diff --git a/CLAUDE.md b/CLAUDE.md
index cf1343b470..9882fb3783 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.1275
+**Current Version:** 0.5.1276
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index f5a16168bd..9ec1ad5619 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5503,7 +5503,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "base64",
@@ -5563,14 +5563,14 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "perry-audio-miniaudio"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "cc",
  "libc",
@@ -5578,7 +5578,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "log",
@@ -5592,7 +5592,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5600,7 +5600,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5608,7 +5608,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5617,7 +5617,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5625,7 +5625,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "base64",
@@ -5637,7 +5637,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5645,7 +5645,7 @@ dependencies = [
 
 [[package]]
 name = "perry-container-compose"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -5674,14 +5674,14 @@ dependencies = [
 
 [[package]]
 name = "perry-container-e2e"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
 ]
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "serde",
  "serde_json",
@@ -5689,7 +5689,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.1275"
+version = "0.5.1276"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5700,7 +5700,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "clap",
@@ -5715,7 +5715,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ads"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "block2",
  "objc2",
@@ -5725,7 +5725,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5733,7 +5733,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5742,7 +5742,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5750,7 +5750,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5758,7 +5758,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5766,7 +5766,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5774,7 +5774,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "chrono",
  "cron",
@@ -5784,7 +5784,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5792,7 +5792,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5800,7 +5800,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5808,7 +5808,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "rand 0.10.1",
@@ -5816,7 +5816,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5824,14 +5824,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5849,7 +5849,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bytes",
  "lazy_static",
@@ -5862,7 +5862,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bytes",
  "h2",
@@ -5886,7 +5886,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5896,7 +5896,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "jsonwebtoken",
@@ -5907,7 +5907,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -5916,7 +5916,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5924,7 +5924,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bson",
  "futures-util",
@@ -5936,7 +5936,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5946,7 +5946,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -5955,7 +5955,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "bytes",
  "perry-ffi",
@@ -5968,7 +5968,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-node-forge"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "const-oid 0.9.6",
  "der 0.7.10",
@@ -5987,7 +5987,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -5997,7 +5997,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pdf"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "printpdf",
@@ -6005,7 +6005,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -6014,7 +6014,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -6022,7 +6022,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "fast_image_resize",
  "image",
@@ -6032,14 +6032,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-slugify"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -6048,7 +6048,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-undici"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -6057,7 +6057,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -6065,7 +6065,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -6075,7 +6075,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -6088,7 +6088,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "brotli",
  "flate2",
@@ -6098,7 +6098,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "dashmap",
  "once_cell",
@@ -6107,7 +6107,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -6125,7 +6125,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -6137,7 +6137,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "base64",
@@ -6178,14 +6178,14 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime-static"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-runtime",
 ]
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "aes 0.8.4",
  "aes 0.9.1",
@@ -6280,14 +6280,14 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib-static"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-stdlib",
 ]
 
 [[package]]
 name = "perry-transform"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -6296,14 +6296,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ui-model",
 ]
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "itoa",
@@ -6320,7 +6320,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "rand 0.10.1",
  "serde",
@@ -6330,7 +6330,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "cairo-rs 0.22.0",
@@ -6353,7 +6353,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "block2",
@@ -6369,7 +6369,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "block2",
@@ -6384,7 +6384,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-model"
-version = "0.5.1275"
+version = "0.5.1276"
 
 [[package]]
 name = "perry-ui-test"
@@ -6395,11 +6395,11 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.1275"
+version = "0.5.1276"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "block2",
@@ -6415,7 +6415,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "block2",
@@ -6431,7 +6431,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "block2",
  "libc",
@@ -6444,7 +6444,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "base64",
  "libc",
@@ -6461,14 +6461,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows-winui"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "perry-ui-windows",
 ]
 
 [[package]]
 name = "perry-updater"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "anyhow",
  "base64",
@@ -6484,7 +6484,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.1275"
+version = "0.5.1276"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 4c0dd894e2..8de3599f96 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -292,7 +292,7 @@ codegen-units = 16
 codegen-units = 16
 
 [workspace.package]
-version = "0.5.1275"
+version = "0.5.1276"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/changelog.d/5756-tanstack-start-compat.md b/changelog.d/5756-tanstack-start-compat.md
new file mode 100644
index 0000000000..70f58e7c5c
--- /dev/null
+++ b/changelog.d/5756-tanstack-start-compat.md
@@ -0,0 +1,8 @@
+- Fix TanStack Start package subpath resolution, JSX/runtime binding selection,
+  closure-contained dynamic imports, and hoisted `TextEncoder`/`TextDecoder`
+  inference.
+- Preserve pull-driven `ReadableStream` bodies through `Response` construction
+  and cloning, reject invalid `GET`/`HEAD` stream bodies before consuming them,
+  and expose the fetch/abort reflection surface expected by response wrappers.
+- Resolve nested `?script-string` assets relative to their importer and preserve
+  their source exactly when generating hydration bootstrap modules.
diff --git a/crates/perry-codegen/src/expr/mod.rs b/crates/perry-codegen/src/expr/mod.rs
index 4b5055341b..b430f5e345 100644
--- a/crates/perry-codegen/src/expr/mod.rs
+++ b/crates/perry-codegen/src/expr/mod.rs
@@ -1527,6 +1527,12 @@ pub(crate) fn class_field_loop_fact_lookup<'f>(
 }
 
 impl<'a> FnCtx<'a> {
+    pub(crate) fn has_imported_extern_binding(&self, name: &str) -> bool {
+        self.imported_vars.contains(name)
+            || self.import_function_prefixes.contains_key(name)
+            || self.import_function_v8_specifiers.contains_key(name)
+    }
+
     /// The `Ptr<Shape>` proof for a receiver expression, if any — the single
     /// entry point every representation-selection object site consults.
     ///
diff --git a/crates/perry-codegen/src/lower_call/extern_func.rs b/crates/perry-codegen/src/lower_call/extern_func.rs
index a272131c5f..f38173d875 100644
--- a/crates/perry-codegen/src/lower_call/extern_func.rs
+++ b/crates/perry-codegen/src/lower_call/extern_func.rs
@@ -1351,7 +1351,7 @@ pub fn try_lower_extern_func_call(
         // scope in #689 and continue to fall through to `js_jsx`; the runtime
         // returns `undefined` for those unrecognised intrinsic sentinels until
         // the rewriter is extended.
-        "jsx" | "jsxs" => {
+        "jsx" | "jsxs" if !ctx.has_imported_extern_binding(name) => {
             if let Some(call) = try_rewrite_perry_tui_jsx_intrinsic(ctx, name == "jsxs", args)? {
                 return Ok(Some(call));
             }
diff --git a/crates/perry-hir/src/dynamic_import/visitors.rs b/crates/perry-hir/src/dynamic_import/visitors.rs
index 48b149bd5f..2c2e8aa9de 100644
--- a/crates/perry-hir/src/dynamic_import/visitors.rs
+++ b/crates/perry-hir/src/dynamic_import/visitors.rs
@@ -461,6 +461,13 @@ fn visit_expr_for_dyn_imports_ref<F: FnMut(&Expr)>(expr: &Expr, f: &mut F) {
             visit_stmt_for_dyn_imports_ref(s, f);
         }
     }
+    // Closure bodies — mirror the mutable visitor so the collect pass and the
+    // fill pass traverse dynamic import sites in the same order.
+    if let Expr::Closure { body, .. } = expr {
+        for s in body {
+            visit_stmt_for_dyn_imports_ref(s, f);
+        }
+    }
     walk_expr_children(expr, &mut |child| visit_expr_for_dyn_imports_ref(child, f));
 }
 
diff --git a/crates/perry-hir/src/jsx.rs b/crates/perry-hir/src/jsx.rs
index 1f496749af..33bc73e0b9 100644
--- a/crates/perry-hir/src/jsx.rs
+++ b/crates/perry-hir/src/jsx.rs
@@ -13,7 +13,8 @@ use crate::lower::{lower_expr, LoweringContext};
 pub(crate) fn lower_jsx_element(ctx: &mut LoweringContext, jsx: &ast::JSXElement) -> Result<Expr> {
     let type_expr = lower_jsx_element_name(ctx, &jsx.opening.name)?;
 
-    let mut props_fields: Vec<(String, Expr)> = Vec::new();
+    let mut props_parts: Vec<(Option<String>, Expr)> = Vec::new();
+    let mut has_spread_attr = false;
     for attr in &jsx.opening.attrs {
         match attr {
             ast::JSXAttrOrSpread::JSXAttr(jsx_attr) => {
@@ -31,12 +32,11 @@ pub(crate) fn lower_jsx_element(ctx: &mut LoweringContext, jsx: &ast::JSXElement
                     None => Expr::Bool(true), // Boolean attribute: <input disabled />
                     Some(val) => lower_jsx_attr_value(ctx, val)?,
                 };
-                props_fields.push((attr_name, attr_val));
+                props_parts.push((Some(attr_name), attr_val));
             }
             ast::JSXAttrOrSpread::SpreadElement(spread) => {
-                // Spread attributes ({...obj}) are not yet representable in HIR Object.
-                // Evaluate for side effects but don't propagate into props.
-                let _ = lower_expr(ctx, &spread.expr);
+                has_spread_attr = true;
+                props_parts.push((None, lower_expr(ctx, &spread.expr)?));
             }
         }
     }
@@ -54,17 +54,24 @@ pub(crate) fn lower_jsx_element(ctx: &mut LoweringContext, jsx: &ast::JSXElement
     match children.len() {
         0 => {}
         1 => {
-            props_fields.push(("children".to_string(), children.remove(0)));
+            props_parts.push((Some("children".to_string()), children.remove(0)));
         }
         _ => {
-            props_fields.push(("children".to_string(), Expr::Array(children)));
+            props_parts.push((Some("children".to_string()), Expr::Array(children)));
         }
     }
 
-    let props_expr = if props_fields.is_empty() {
+    let props_expr = if props_parts.is_empty() {
         Expr::Null
+    } else if has_spread_attr {
+        Expr::ObjectSpread { parts: props_parts }
     } else {
-        Expr::Object(props_fields)
+        Expr::Object(
+            props_parts
+                .into_iter()
+                .map(|(key, value)| (key.expect("non-spread JSX prop"), value))
+                .collect(),
+        )
     };
 
     // #4950: a module that default-imports the npm `react` package gets
diff --git a/crates/perry-hir/src/lower/expr_function.rs b/crates/perry-hir/src/lower/expr_function.rs
index e5e2d7247a..380884ac1a 100644
--- a/crates/perry-hir/src/lower/expr_function.rs
+++ b/crates/perry-hir/src/lower/expr_function.rs
@@ -28,6 +28,9 @@ use crate::lower_patterns::{
     generate_param_destructuring_stmts, get_param_default, get_pat_name, get_pat_type,
     is_destructuring_pattern, is_rest_param,
 };
+use crate::lower_types::hoisted_text_codec::{
+    infer_hoisted_text_codec_var_type, require_literal_specifier,
+};
 
 use super::{lower_expr, LoweringContext};
 
@@ -779,6 +782,7 @@ fn lower_fn_expr_anon(ctx: &mut LoweringContext, fn_expr: &ast::FnExpr) -> Resul
         // shared synthetic class id on the instance and dispatch finds
         // the prototype methods. Same shallow-walk policy as the
         // codegen-side `referenced_from_fn` pre-scan.
+        let mut builtin_aliases_in_var_decl = std::collections::HashSet::new();
         for stmt in &block.stmts {
             if let ast::Stmt::Decl(ast::Decl::Var(var_decl)) = stmt {
                 if var_decl.kind == ast::VarDeclKind::Var {
@@ -801,12 +805,34 @@ fn lower_fn_expr_anon(ctx: &mut LoweringContext, fn_expr: &ast::FnExpr) -> Resul
                             &decl.name, &mut names,
                         );
                         for name in names {
+                            let ty = if let ast::Pat::Ident(ident) = &decl.name {
+                                if decl.init.as_deref().and_then(require_literal_specifier)
+                                    == Some("util")
+                                    || decl.init.as_deref().and_then(require_literal_specifier)
+                                        == Some("node:util")
+                                {
+                                    builtin_aliases_in_var_decl.insert(name.clone());
+                                }
+                                infer_hoisted_text_codec_var_type(decl, ident, |name| {
+                                    builtin_aliases_in_var_decl.contains(name)
+                                        || matches!(
+                                            ctx.lookup_builtin_module_alias(name),
+                                            Some("util" | "node:util")
+                                        )
+                                        || matches!(
+                                            ctx.lookup_native_module(name),
+                                            Some(("util" | "node:util", None))
+                                        )
+                                })
+                            } else {
+                                Type::Any
+                            };
                             let already_in_scope = ctx
                                 .locals
                                 .lookup_index_in_scope(&name, outer_locals_len)
                                 .is_some();
                             if !already_in_scope {
-                                let id = ctx.define_local(name.clone(), Type::Any);
+                                let id = ctx.define_local(name.clone(), ty.clone());
                                 // Mark as hoisted so closures created
                                 // before the var's init expression see
                                 // it through a box (mutable capture),
@@ -855,7 +881,7 @@ fn lower_fn_expr_anon(ctx: &mut LoweringContext, fn_expr: &ast::FnExpr) -> Resul
                                 nested_var_prologue.push(Stmt::Let {
                                     id,
                                     name,
-                                    ty: Type::Any,
+                                    ty,
                                     mutable: true,
                                     init: Some(Expr::Undefined),
                                 });
diff --git a/crates/perry-hir/src/lower/lower_module_fn.rs b/crates/perry-hir/src/lower/lower_module_fn.rs
index 1cfacfce5f..d5268fd86c 100644
--- a/crates/perry-hir/src/lower/lower_module_fn.rs
+++ b/crates/perry-hir/src/lower/lower_module_fn.rs
@@ -14,32 +14,93 @@ use swc_ecma_ast as ast;
 
 use super::*;
 use crate::ir::*;
+use crate::lower_types::hoisted_text_codec::{
+    infer_hoisted_text_codec_var_type, require_literal_specifier,
+};
 
-fn module_has_strict_mode(ast_module: &ast::Module, source_file_path: &str) -> bool {
-    // A file is strict-mode code exactly when Node runs it as an ES module. Three
-    // independent signals make it one (#6542); any is sufficient:
-    //
-    // 1. The module FORMAT — an ESM extension (`.mjs`/`.mts`) or an ESM package
-    //    context (`"type":"module"`). This holds even with NO in-file import/
-    //    export syntax: e.g. Perry's own test-suite `.ts` files carry no module
-    //    syntax yet run strict because the repo's `package.json` sets
-    //    `"type":"module"`, so `Object.freeze(o); o.x = 1` must throw there.
-    if perry_parser::file_is_es_module_by_format(source_file_path) {
-        return true;
+fn should_enable_react_automatic_jsx(name: &str, ast_module: &ast::Module) -> bool {
+    let is_jsx_source = name.ends_with(".tsx")
+        || name.ends_with(".jsx")
+        || name.contains(".tsx?")
+        || name.contains(".jsx?");
+    if !is_jsx_source {
+        return false;
+    }
+
+    let mut has_explicit_react_import = false;
+    let mut has_react_ecosystem_import = false;
+    for item in &ast_module.body {
+        let ast::ModuleItem::ModuleDecl(ast::ModuleDecl::Import(import)) = item else {
+            continue;
+        };
+        let source = import.src.value.to_string_lossy().to_string();
+        let has_runtime_value = !import.type_only
+            && (import.specifiers.is_empty()
+                || import.specifiers.iter().any(|specifier| match specifier {
+                    ast::ImportSpecifier::Named(named) => !named.is_type_only,
+                    ast::ImportSpecifier::Default(_) | ast::ImportSpecifier::Namespace(_) => true,
+                }));
+        let provides_react_object = !import.type_only
+            && import.specifiers.iter().any(|specifier| {
+                matches!(
+                    specifier,
+                    ast::ImportSpecifier::Default(_) | ast::ImportSpecifier::Namespace(_)
+                )
+            });
+        if source == "react" && provides_react_object {
+            has_explicit_react_import = true;
+        }
+        if has_runtime_value
+            && (source.starts_with("@tanstack/react-")
+                || source == "@tanstack/react-router"
+                || source == "react/jsx-runtime")
+        {
+            has_react_ecosystem_import = true;
+        }
+    }
+
+    if has_explicit_react_import {
+        return false;
     }
-    // 2. An ES `import`/`export` ANYWHERE in the body makes the source a Module
-    //    (Source Text Module Record) even outside any package context — the
-    //    declaration need not precede other statements, so a trailing
-    //    `export {}` or a `const x = 1; export function f() {}` both count.
-    if ast_module
-        .body
-        .iter()
-        .any(|item| matches!(item, ast::ModuleItem::ModuleDecl(_)))
+
+    has_react_ecosystem_import
+        || name.contains("node_modules/@tanstack/react-")
+        || name.contains("node_modules/@tanstack/react-router/")
+}
+
+fn enable_react_automatic_jsx(module: &mut Module, ctx: &mut LoweringContext) {
+    const LOCAL: &str = "__perry_react_auto";
+    let local = LOCAL.to_string();
+    ctx.register_imported_func(local.clone(), local.clone());
+    ctx.namespace_import_locals.insert(local.clone());
+    ctx.namespace_import_sources
+        .insert(local.clone(), "react".to_string());
+    ctx.react_default_import_local = Some(local.clone());
+    module.imports.push(Import {
+        source: "react".to_string(),
+        specifiers: vec![ImportSpecifier::Namespace { local }],
+        is_native: false,
+        module_kind: ModuleKind::NativeCompiled,
+        resolved_path: None,
+        type_only: false,
+        is_dynamic: false,
+        is_dynamic_target: false,
+        is_deferred_require: false,
+        is_adopted_require: false,
+    });
+}
+
+fn module_has_strict_mode(ast_module: &ast::Module, source_file_path: &str) -> bool {
+    // Node treats ESM format/package context and any source-text module as
+    // strict even without a directive prologue (#6542).
+    if perry_parser::file_is_es_module_by_format(source_file_path)
+        || ast_module
+            .body
+            .iter()
+            .any(|item| matches!(item, ast::ModuleItem::ModuleDecl(_)))
     {
         return true;
     }
-    // 3. Otherwise this is CommonJS script text; it is strict only if the
-    //    directive prologue opens with a `"use strict"` directive.
     for item in &ast_module.body {
         let ast::ModuleItem::Stmt(stmt) = item else {
             break;
@@ -435,6 +496,9 @@ pub fn lower_module_full(
         ctx.seed_imported_class_accessors(seed);
     }
     let mut module = Module::new(name);
+    if should_enable_react_automatic_jsx(name, ast_module) {
+        enable_react_automatic_jsx(&mut module, &mut ctx);
+    }
 
     // Pre-scan for `new Function` / `Function(...)` constant-argument
     // resolution: single-assignment module vars, `toString`-bearing object
@@ -609,6 +673,7 @@ pub fn lower_module_full(
 
     // Pre-register module-level variable declarations so function bodies
     // declared before the variable can still reference them via lookup_local
+    let mut builtin_aliases_in_module_vars = HashSet::new();
     for item in &ast_module.body {
         let var_decl = match item {
             ast::ModuleItem::Stmt(ast::Stmt::Decl(ast::Decl::Var(v))) => Some(v),
@@ -637,12 +702,24 @@ pub fn lower_module_full(
                 }
                 if let ast::Pat::Ident(ident) = &decl.name {
                     let name = ident.id.sym.to_string();
+                    if decl.init.as_deref().and_then(require_literal_specifier) == Some("util")
+                        || decl.init.as_deref().and_then(require_literal_specifier)
+                            == Some("node:util")
+                    {
+                        builtin_aliases_in_module_vars.insert(name.clone());
+                    }
                     if ctx.lookup_local(&name).is_none() {
-                        let ty = ident
-                            .type_ann
-                            .as_ref()
-                            .map(|ann| extract_ts_type(&ann.type_ann))
-                            .unwrap_or(Type::Any);
+                        let ty = infer_hoisted_text_codec_var_type(decl, ident, |name| {
+                            builtin_aliases_in_module_vars.contains(name)
+                                || matches!(
+                                    ctx.lookup_builtin_module_alias(name),
+                                    Some("util" | "node:util")
+                                )
+                                || matches!(
+                                    ctx.lookup_native_module(name),
+                                    Some(("util" | "node:util", None))
+                                )
+                        });
                         ctx.define_local(name.clone(), ty);
                         ctx.pre_registered_module_vars.insert(name);
                         if var_decl.kind == ast::VarDeclKind::Var {
diff --git a/crates/perry-hir/src/lower/module_decl.rs b/crates/perry-hir/src/lower/module_decl.rs
index 798eae6287..8f30d150ce 100644
--- a/crates/perry-hir/src/lower/module_decl.rs
+++ b/crates/perry-hir/src/lower/module_decl.rs
@@ -412,7 +412,7 @@ pub(crate) fn lower_module_decl(
                             // so JSX in this module lowers to
                             // `<local>.createElement(...)` instead of Perry's
                             // eager `js_jsx` adapter (see jsx.rs).
-                            if source == "react" {
+                            if source == "react" && !whole_decl_type_only {
                                 ctx.react_default_import_local = Some(local.clone());
                             }
                         }
@@ -443,6 +443,15 @@ pub(crate) fn lower_module_decl(
                             // not lower to StaticMethodCall — see the heuristic
                             // in expr_call::static_and_instance.
                             ctx.namespace_import_locals.insert(local.clone());
+                            // React namespace imports are the common TSX shape
+                            // (`import * as React from "react"`). They need the
+                            // same non-eager React element semantics as default
+                            // React imports; Perry's native JSX adapter calls
+                            // function components immediately and therefore runs
+                            // hooks outside the reconciler.
+                            if source == "react" && !whole_decl_type_only {
+                                ctx.react_default_import_local = Some(local.clone());
+                            }
                             // Remember the source so a later bare `export { local }`
                             // re-exports the namespace itself rather than a bare
                             // function symbol (see the local-export branch below).
diff --git a/crates/perry-hir/src/lower_types.rs b/crates/perry-hir/src/lower_types.rs
index 8360c793e1..5e830cbfd2 100644
--- a/crates/perry-hir/src/lower_types.rs
+++ b/crates/perry-hir/src/lower_types.rs
@@ -308,6 +308,8 @@ const INFER_TYPE_RECURSION_CAP: u32 = 48;
 const INFER_TYPE_STACK_RED_ZONE: usize = 256 * 1024;
 const INFER_TYPE_STACK_SEGMENT: usize = 2 * 1024 * 1024;
 
+pub(crate) mod hoisted_text_codec;
+
 pub(crate) fn infer_type_from_expr(expr: &ast::Expr, ctx: &LoweringContext) -> Type {
     thread_local! {
         static INFER_DEPTH: std::cell::Cell<u32> = const { std::cell::Cell::new(0) };
diff --git a/crates/perry-hir/src/lower_types/hoisted_text_codec.rs b/crates/perry-hir/src/lower_types/hoisted_text_codec.rs
new file mode 100644
index 0000000000..e4c41cf48e
--- /dev/null
+++ b/crates/perry-hir/src/lower_types/hoisted_text_codec.rs
@@ -0,0 +1,77 @@
+use crate::types::Type;
+use swc_ecma_ast as ast;
+
+use super::extract_ts_type;
+
+pub(crate) fn peel_expr_for_hoisted_var_type(expr: &ast::Expr) -> &ast::Expr {
+    match expr {
+        ast::Expr::Paren(paren) => peel_expr_for_hoisted_var_type(&paren.expr),
+        ast::Expr::TsAs(ts_as) => peel_expr_for_hoisted_var_type(&ts_as.expr),
+        ast::Expr::TsTypeAssertion(ts_assert) => peel_expr_for_hoisted_var_type(&ts_assert.expr),
+        ast::Expr::TsNonNull(non_null) => peel_expr_for_hoisted_var_type(&non_null.expr),
+        ast::Expr::TsConstAssertion(const_assert) => {
+            peel_expr_for_hoisted_var_type(&const_assert.expr)
+        }
+        _ => expr,
+    }
+}
+
+pub(crate) fn require_literal_specifier(expr: &ast::Expr) -> Option<&str> {
+    let ast::Expr::Call(call) = peel_expr_for_hoisted_var_type(expr) else {
+        return None;
+    };
+    let ast::Callee::Expr(callee) = &call.callee else {
+        return None;
+    };
+    let ast::Expr::Ident(ident) = callee.as_ref() else {
+        return None;
+    };
+    if ident.sym.as_ref() != "require" {
+        return None;
+    }
+    let first_arg = call.args.first()?;
+    let ast::Expr::Lit(ast::Lit::Str(specifier)) = peel_expr_for_hoisted_var_type(&first_arg.expr)
+    else {
+        return None;
+    };
+    Some(specifier.value.as_str().unwrap_or(""))
+}
+
+pub(crate) fn infer_hoisted_text_codec_var_type(
+    decl: &ast::VarDeclarator,
+    ident: &ast::BindingIdent,
+    is_util_alias: impl Fn(&str) -> bool,
+) -> Type {
+    if let Some(ann) = ident.type_ann.as_ref() {
+        return extract_ts_type(&ann.type_ann);
+    }
+
+    let Some(init) = decl.init.as_deref().map(peel_expr_for_hoisted_var_type) else {
+        return Type::Any;
+    };
+    let ast::Expr::New(new_expr) = init else {
+        return Type::Any;
+    };
+
+    match peel_expr_for_hoisted_var_type(new_expr.callee.as_ref()) {
+        ast::Expr::Ident(ctor) => match ctor.sym.as_ref() {
+            "TextEncoder" | "TextDecoder" => Type::Named(ctor.sym.to_string()),
+            _ => Type::Any,
+        },
+        ast::Expr::Member(member) => {
+            let (ast::Expr::Ident(obj), ast::MemberProp::Ident(prop)) =
+                (member.obj.as_ref(), &member.prop)
+            else {
+                return Type::Any;
+            };
+            let prop_name = prop.sym.as_ref();
+            if matches!(prop_name, "TextEncoder" | "TextDecoder") && is_util_alias(obj.sym.as_ref())
+            {
+                Type::Named(prop_name.to_string())
+            } else {
+                Type::Any
+            }
+        }
+        _ => Type::Any,
+    }
+}
diff --git a/crates/perry-runtime/src/object/global_this/fetch_globals.rs b/crates/perry-runtime/src/object/global_this/fetch_globals.rs
index 66e2d66e7b..e342ab31f2 100644
--- a/crates/perry-runtime/src/object/global_this/fetch_globals.rs
+++ b/crates/perry-runtime/src/object/global_this/fetch_globals.rs
@@ -547,6 +547,45 @@ fn is_uncallable_builtin_super_parent(name: &str) -> bool {
     )
 }
 
+fn is_uncallable_builtin_super_parent_class_id(class_id: u32) -> bool {
+    if class_id == 0 {
+        return false;
+    }
+    const NAMES: &[&str] = &[
+        "Map",
+        "Set",
+        "WeakMap",
+        "WeakSet",
+        "Array",
+        "ArrayBuffer",
+        "DataView",
+        "Boolean",
+        "Number",
+        "String",
+        "Date",
+        "RegExp",
+        "Promise",
+        "Function",
+        "BigInt",
+        "Symbol",
+        "Object",
+        "Int8Array",
+        "Uint8Array",
+        "Uint8ClampedArray",
+        "Int16Array",
+        "Uint16Array",
+        "Int32Array",
+        "Uint32Array",
+        "Float32Array",
+        "Float64Array",
+        "BigInt64Array",
+        "BigUint64Array",
+    ];
+    NAMES
+        .iter()
+        .any(|name| super::super::instanceof::global_builtin_constructor_class_id(name) == class_id)
+}
+
 /// `super(...)` for `class X extends <runtime-value constructor>` where the
 /// parent expression is an alias of the global `Request`/`Response` constructor
 /// — e.g. `@hono/node-server`'s `class Request extends GlobalRequest` with
@@ -835,6 +874,17 @@ pub unsafe extern "C" fn js_fetch_or_value_super(
             }
             let usable = if bits & TAG_MASK == POINTER_TAG {
                 let p = (bits & PTR_MASK) as usize;
+                if super::super::class_registry::is_class_object_ptr(p as *const u8) {
+                    let parent_cid = crate::object::js_object_get_class_id(p as *const _);
+                    if parent_cid != 0 {
+                        if let Some(obj) = subclass_this_object_ptr(this_box) {
+                            super::super::class_constructors::run_class_constructor_on_this_flat(
+                                parent_cid, obj as i64, args_ptr, args_len,
+                            );
+                        }
+                    }
+                    return undef;
+                }
                 // A real callability test: a closure, or a per-evaluation class
                 // OBJECT (constructor). The prior `class_id != 0` accepted any
                 // pointer-tagged object with a class id — including non-callable
@@ -842,7 +892,6 @@ pub unsafe extern "C" fn js_fetch_or_value_super(
                 // skipped the `parent_closure_in_chain` recovery below and
                 // dispatched `js_native_call_value` on a non-function.
                 crate::closure::is_closure_ptr(p)
-                    || super::super::class_registry::is_class_object_ptr(p as *const u8)
             } else {
                 // INT32-tagged ClassRefs route through the static super paths
                 // before reaching here; anything else (undefined / a stale
@@ -854,6 +903,15 @@ pub unsafe extern "C" fn js_fetch_or_value_super(
                     let cid = crate::object::js_object_get_class_id(obj);
                     if let Some(addr) = super::super::class_registry::parent_closure_in_chain(cid) {
                         callee = f64::from_bits(POINTER_TAG | addr as u64);
+                    } else if let Some(parent_cid) = crate::object::get_parent_class_id(cid) {
+                        if parent_cid != 0
+                            && !is_uncallable_builtin_super_parent_class_id(parent_cid)
+                        {
+                            super::super::class_constructors::run_class_constructor_on_this_flat(
+                                parent_cid, obj as i64, args_ptr, args_len,
+                            );
+                            return undef;
+                        }
                     }
                 }
             }
diff --git a/crates/perry-runtime/src/object/global_this/proto_methods.rs b/crates/perry-runtime/src/object/global_this/proto_methods.rs
index 3d0d99d200..4a4ee0e086 100644
--- a/crates/perry-runtime/src/object/global_this/proto_methods.rs
+++ b/crates/perry-runtime/src/object/global_this/proto_methods.rs
@@ -649,6 +649,62 @@ pub(crate) fn populate_builtin_prototype_methods(builtin_name: &str, proto_obj:
                     ("text", 0),
                 ],
             );
+            // Web Fetch accessors must be visible as accessor descriptors on
+            // the intrinsic prototype, not just as compiler-known handle
+            // fields. Libraries such as srvx copy `Response.prototype`
+            // descriptors onto lightweight response wrappers and provide their
+            // own getter body. If these names are absent from reflection, the
+            // wrapper's inherited `.body`/`.headers` reads become undefined and
+            // streamed SSR responses are dropped before the underlying stream
+            // is ever pulled.
+            let accessors: &[&str] = if builtin_name == "Response" {
+                &[
+                    "body",
+                    "bodyUsed",
+                    "headers",
+                    "ok",
+                    "redirected",
+                    "status",
+                    "statusText",
+                    "type",
+                    "url",
+                ]
+            } else {
+                &[
+                    "body",
+                    "bodyUsed",
+                    "cache",
+                    "credentials",
+                    "destination",
+                    "duplex",
+                    "headers",
+                    "integrity",
+                    "keepalive",
+                    "method",
+                    "mode",
+                    "redirect",
+                    "referrer",
+                    "referrerPolicy",
+                    "signal",
+                    "url",
+                ]
+            };
+            unsafe {
+                crate::closure::js_register_closure_arity(
+                    global_this_builtin_noop_thunk as *const u8,
+                    0,
+                );
+                for name in accessors {
+                    let getter = crate::closure::js_closure_alloc(
+                        global_this_builtin_noop_thunk as *const u8,
+                        0,
+                    );
+                    if !getter.is_null() {
+                        let getter_bits = crate::value::js_nanbox_pointer(getter as i64).to_bits();
+                        install_builtin_getter(proto_obj, name, getter_bits);
+                    }
+                }
+            }
             install_noop_proto_methods(proto_obj, OBJECT_PROTO_METHODS);
         }
         #[cfg(feature = "global-webfetch")]
diff --git a/crates/perry-runtime/src/object/instanceof.rs b/crates/perry-runtime/src/object/instanceof.rs
index f69b48ae5f..e686164c51 100644
--- a/crates/perry-runtime/src/object/instanceof.rs
+++ b/crates/perry-runtime/src/object/instanceof.rs
@@ -513,6 +513,7 @@ pub(crate) fn global_builtin_constructor_class_id(name: &str) -> u32 {
         "WeakSet" => 0xFFFF002D,
         "RegExp" => 0xFFFF0021,
         "ArrayBuffer" => 0xFFFF0025,
+        "DataView" => 0xFFFF002B,
         "Array" => 0xFFFF0024,
         "Object" => 0xFFFF0050,
         "Function" => CLASS_ID_FUNCTION,
diff --git a/crates/perry-runtime/src/url/abort.rs b/crates/perry-runtime/src/url/abort.rs
index 7fd7c364c9..71756ab3a0 100644
--- a/crates/perry-runtime/src/url/abort.rs
+++ b/crates/perry-runtime/src/url/abort.rs
@@ -21,7 +21,9 @@ const ABORT_METHOD_FIELD: u32 = 2;
 //   field 0: aborted (bool)
 //   field 1: reason (any)
 //   field 2: listeners (array of closure f64 values; may be null/undefined if empty)
-const ABORT_SIGNAL_FIELD_COUNT: u32 = 3;
+//   field 3: addEventListener method
+//   field 4: removeEventListener method
+const ABORT_SIGNAL_FIELD_COUNT: u32 = 5;
 
 const TAG_UNDEFINED_AC: u64 = 0x7FFC_0000_0000_0001;
 const TAG_TRUE_AC: u64 = 0x7FFC_0000_0000_0004;
@@ -53,13 +55,49 @@ fn alloc_abort_signal() -> *mut ObjectHeader {
     signal_keys = js_array_push_f64(signal_keys, create_string_f64("aborted"));
     signal_keys = js_array_push_f64(signal_keys, create_string_f64("reason"));
     signal_keys = js_array_push_f64(signal_keys, create_string_f64("_listeners"));
+    signal_keys = js_array_push_f64(signal_keys, create_string_f64("addEventListener"));
+    signal_keys = js_array_push_f64(signal_keys, create_string_f64("removeEventListener"));
     js_object_set_keys(signal, signal_keys);
     js_object_set_field_f64(signal, 0, f64::from_bits(TAG_FALSE_AC));
     js_object_set_field_f64(signal, 1, f64::from_bits(TAG_UNDEFINED_AC));
     js_object_set_field_f64(signal, 2, f64::from_bits(TAG_UNDEFINED_AC));
+    js_object_set_field_f64(signal, 3, abort_signal_listener_method_value(signal, true));
+    js_object_set_field_f64(signal, 4, abort_signal_listener_method_value(signal, false));
     signal
 }
 
+extern "C" fn abort_signal_add_event_listener_method(
+    closure: *const crate::closure::ClosureHeader,
+    event_type: f64,
+    listener: f64,
+) -> f64 {
+    let signal = crate::closure::js_closure_get_capture_ptr(closure, 0) as *mut ObjectHeader;
+    js_abort_signal_add_listener(signal, event_type, listener);
+    f64::from_bits(crate::value::TAG_UNDEFINED)
+}
+
+extern "C" fn abort_signal_remove_event_listener_method(
+    closure: *const crate::closure::ClosureHeader,
+    event_type: f64,
+    listener: f64,
+) -> f64 {
+    let signal = crate::closure::js_closure_get_capture_ptr(closure, 0) as *mut ObjectHeader;
+    js_abort_signal_remove_listener(signal, event_type, listener);
+    f64::from_bits(crate::value::TAG_UNDEFINED)
+}
+
+fn abort_signal_listener_method_value(signal: *mut ObjectHeader, add: bool) -> f64 {
+    let func = if add {
+        abort_signal_add_event_listener_method as *const u8
+    } else {
+        abort_signal_remove_event_listener_method as *const u8
+    };
+    crate::closure::js_register_closure_arity(func, 2);
+    let closure = crate::closure::js_closure_alloc(func, 1);
+    crate::closure::js_closure_set_capture_ptr(closure, 0, signal as i64);
+    crate::value::js_nanbox_pointer(closure as i64)
+}
+
 extern "C" fn abort_controller_abort_method(
     closure: *const crate::closure::ClosureHeader,
     reason: f64,
diff --git a/crates/perry-stdlib/src/fetch/abort_bridge.rs b/crates/perry-stdlib/src/fetch/abort_bridge.rs
index 3d9a7c401a..f160cd9b1f 100644
--- a/crates/perry-stdlib/src/fetch/abort_bridge.rs
+++ b/crates/perry-stdlib/src/fetch/abort_bridge.rs
@@ -229,6 +229,7 @@ pub(crate) async fn run_request(
                         redirected: false,
                         cached_headers_id: None,
                         cached_body_stream_id: None,
+                        body_stream_id: None,
                     },
                 );
                 let result_bits = super::handle_to_f64(response_id).to_bits();
diff --git a/crates/perry-stdlib/src/fetch/body_metadata.rs b/crates/perry-stdlib/src/fetch/body_metadata.rs
index 86ff208b00..ddf0ece719 100644
--- a/crates/perry-stdlib/src/fetch/body_metadata.rs
+++ b/crates/perry-stdlib/src/fetch/body_metadata.rs
@@ -202,6 +202,7 @@ pub extern "C" fn js_response_static_error() -> f64 {
             redirected: false,
             cached_headers_id: None,
             cached_body_stream_id: None,
+            body_stream_id: None,
         },
     );
     handle_to_f64(id)
diff --git a/crates/perry-stdlib/src/fetch/dispatch.rs b/crates/perry-stdlib/src/fetch/dispatch.rs
index ef824cc38b..2f5530eaff 100644
--- a/crates/perry-stdlib/src/fetch/dispatch.rs
+++ b/crates/perry-stdlib/src/fetch/dispatch.rs
@@ -64,10 +64,13 @@ pub extern "C" fn js_response_body_init_ptr(value: f64) -> i64 {
             .contains(&value)
     {
         let id = value as usize;
-        // kind == 1 ⇒ live ReadableStream.
+        // kind == 1 ⇒ live ReadableStream. Stash it for the constructor that
+        // requested the body-init conversion: Request drains it to bytes, while
+        // Response preserves it lazily because transformed SSR streams often
+        // produce data only when the downstream consumer pulls.
         if crate::streams::js_stream_handle_kind(id) == 1 {
-            let bytes = crate::streams::drain_readable_into_bytes(id);
-            return js_string_from_bytes(bytes.as_ptr(), bytes.len() as u32) as i64;
+            PENDING_FETCH_BODY_STREAM_ID.with(|pending| pending.set(id));
+            return 0;
         }
     }
     // #5437: a Node `IncomingMessage` body — the request-body bridge Next.js's
diff --git a/crates/perry-stdlib/src/fetch/mod.rs b/crates/perry-stdlib/src/fetch/mod.rs
index 09bd4b2779..5560d2cd9f 100644
--- a/crates/perry-stdlib/src/fetch/mod.rs
+++ b/crates/perry-stdlib/src/fetch/mod.rs
@@ -7,6 +7,7 @@ use perry_runtime::{
     js_array_alloc, js_array_push, js_object_alloc, js_object_set_field, js_object_set_keys,
     js_string_from_bytes, JSValue, StringHeader,
 };
+use std::cell::Cell;
 use std::collections::HashMap;
 use std::sync::Mutex;
 
@@ -44,6 +45,12 @@ pub use body_metadata::*;
 mod request_ctor;
 pub use request_ctor::*;
 
+// Web Fetch `Response` constructor/accessors — split out to keep this file
+// under the 2,000-line lint gate.
+mod response_ctor;
+use response_ctor::alloc_response;
+pub use response_ctor::{js_response_clone, js_response_get_headers, js_response_new};
+
 // Web Fetch constructor validation helpers (#2640 / #2643) — split out to
 // keep this file under the 2,000-line lint gate.
 mod validation;
@@ -264,6 +271,27 @@ struct FetchResponse {
     /// each time would silently un-lock a reader). None for an empty body —
     /// `Response.body` is `ReadableStream | null` (#1650).
     cached_body_stream_id: Option<usize>,
+    /// Original ReadableStream body passed to `new Response(stream, init)`.
+    /// Unlike buffered bodies, this must stay lazy: constructing a Response
+    /// must not synchronously drain a producer whose chunks appear only after
+    /// downstream pulls (TanStack Start / React SSR relies on that).
+    body_stream_id: Option<usize>,
+}
+
+thread_local! {
+    static PENDING_FETCH_BODY_STREAM_ID: Cell<usize> = const { Cell::new(0) };
+}
+
+fn take_pending_fetch_body_stream_id() -> Option<usize> {
+    PENDING_FETCH_BODY_STREAM_ID.with(|pending| {
+        let id = pending.get();
+        pending.set(0);
+        if id != 0 && crate::streams::js_stream_handle_kind(id) == 1 {
+            Some(id)
+        } else {
+            None
+        }
+    })
 }
 
 /// Extract the registry id from a Web Fetch handle f64 value.
@@ -428,6 +456,7 @@ pub unsafe extern "C" fn js_fetch_get(url_ptr: *const StringHeader) -> *mut perr
                         redirected: false,
                         cached_headers_id: None,
                         cached_body_stream_id: None,
+                        body_stream_id: None,
                     },
                 );
 
@@ -503,6 +532,7 @@ pub unsafe extern "C" fn js_fetch_get_with_auth(
                         redirected: false,
                         cached_headers_id: None,
                         cached_body_stream_id: None,
+                        body_stream_id: None,
                     },
                 );
 
@@ -580,6 +610,7 @@ pub unsafe extern "C" fn js_fetch_post_with_auth(
                         redirected: false,
                         cached_headers_id: None,
                         cached_body_stream_id: None,
+                        body_stream_id: None,
                     },
                 );
 
@@ -664,6 +695,7 @@ pub unsafe extern "C" fn js_fetch_post(
                         redirected: false,
                         cached_headers_id: None,
                         cached_body_stream_id: None,
+                        body_stream_id: None,
                     },
                 );
 
@@ -793,18 +825,24 @@ pub extern "C" fn js_response_body_used(handle: f64) -> f64 {
 
 fn consume_response_body(handle: f64) -> Result<Vec<u8>, &'static str> {
     let response_id = handle_id(handle);
-    let mut guard = FETCH_RESPONSES.lock().unwrap();
-    let resp = guard
-        .get_mut(&response_id)
-        .ok_or("Invalid response handle")?;
-    if !resp.body_present {
-        return Ok(Vec::new());
-    }
-    if resp.body_used {
-        return Err(BODY_ALREADY_USED_MESSAGE);
+    let (body, stream_id) = {
+        let mut guard = FETCH_RESPONSES.lock().unwrap();
+        let resp = guard
+            .get_mut(&response_id)
+            .ok_or("Invalid response handle")?;
+        if !resp.body_present {
+            return Ok(Vec::new());
+        }
+        if resp.body_used {
+            return Err(BODY_ALREADY_USED_MESSAGE);
+        }
+        resp.body_used = true;
+        (resp.body.clone(), resp.body_stream_id)
+    };
+    if let Some(stream_id) = stream_id {
+        return Ok(crate::streams::drain_readable_into_bytes(stream_id));
     }
-    resp.body_used = true;
-    Ok(resp.body.clone())
+    Ok(body)
 }
 
 /// Get response body as text
@@ -1264,156 +1302,12 @@ fn alloc_headers(store: HeadersStore) -> usize {
     id
 }
 
-fn alloc_response(
-    status: u16,
-    status_text: String,
-    headers: HeadersStore,
-    body: Vec<u8>,
-    body_present: bool,
-) -> usize {
-    let id = alloc_fetch_handle_id();
-    FETCH_RESPONSES.lock().unwrap().insert(
-        id,
-        FetchResponse {
-            status,
-            status_text,
-            headers,
-            body,
-            body_present,
-            body_used: false,
-            type_name: "default".to_string(),
-            url: String::new(),
-            redirected: false,
-            cached_headers_id: None,
-            cached_body_stream_id: None,
-        },
-    );
-    id
-}
-
 // ----------------- Headers FFI -----------------
 // Moved to the `headers` sub-module (#1649 pushed fetch.rs past the 2,000-line
 // lint gate; mirrors the earlier fetch_blob.rs extraction). Re-exported below.
 
 // ----------------- Response FFI (constructor + extra methods) -----------------
 
-/// new Response(body, statusOpt, statusTextPtrOpt, headersHandleOpt)
-/// - body_ptr: StringHeader for the body, or null for ""
-/// - status: f64 (200 default)
-/// - status_text_ptr: StringHeader for statusText, or null for ""
-/// - headers_handle: f64 numeric handle from js_headers_new, or 0
-#[no_mangle]
-pub unsafe extern "C" fn js_response_new(
-    body_ptr: *const StringHeader,
-    status: f64,
-    status_text_ptr: *const StringHeader,
-    headers_handle: f64,
-) -> f64 {
-    // Lossless raw-byte read so binary bodies survive byte-for-byte (#5435).
-    let body_opt = dispatch::body_bytes_from_header(body_ptr);
-    let body_present = body_opt.is_some();
-    let body = body_opt.unwrap_or_default();
-    // NaN / 0.0 are the codegen "no status field" sentinels. Node defaults
-    // missing status to 200; any explicit value is truncated toward zero
-    // then range-checked against 200..=599 (199.9 → RangeError, 599.9 →
-    // 599). Refs #2640.
-    let status_u16 = if status.is_nan() || status == 0.0 {
-        200
-    } else {
-        let truncated = status.trunc();
-        if !(200.0..=599.0).contains(&truncated) {
-            throw_fetch_range_error(
-                "init[\"status\"] must be in the range of 200 to 599, inclusive.",
-            );
-        }
-        truncated as u16
-    };
-    // Node defaults statusText to the empty string (NOT the canonical
-    // reason phrase) and validates the reason-phrase token. Refs #2640.
-    let status_text = match string_from_header(status_text_ptr) {
-        Some(s) => {
-            if !is_valid_status_text(&s) {
-                throw_fetch_type_error("Invalid statusText");
-            }
-            s
-        }
-        None => String::new(),
-    };
-    if body_present && is_null_body_status(status_u16) {
-        throw_fetch_type_error(&format!(
-            "Response constructor: Invalid response status code {status_u16}"
-        ));
-    }
-    let headers_id = handle_id(headers_handle);
-    let headers = if headers_id != 0 {
-        HEADERS_REGISTRY
-            .lock()
-            .unwrap()
-            .get(&headers_id)
-            .cloned()
-            .unwrap_or_default()
-    } else {
-        HeadersStore::default()
-    };
-    handle_to_f64(alloc_response(
-        status_u16,
-        status_text,
-        headers,
-        body,
-        body_present,
-    ))
-}
-
-/// response.headers — returns a Headers handle (f64). Lazily allocates a Headers entry
-/// from the response's stored header HashMap if one doesn't exist yet.
-#[no_mangle]
-pub extern "C" fn js_response_get_headers(handle: f64) -> f64 {
-    let id = handle_id(handle);
-    let store = {
-        let guard = FETCH_RESPONSES.lock().unwrap();
-        match guard.get(&id) {
-            Some(resp) => resp.headers.clone(),
-            None => return f64::from_bits(TAG_UNDEFINED),
-        }
-    };
-    handle_to_f64(alloc_headers(store))
-}
-
-/// response.clone() — duplicates the response (deep copy of body + headers)
-#[no_mangle]
-pub extern "C" fn js_response_clone(handle: f64) -> f64 {
-    let id = handle_id(handle);
-    let cloned = {
-        let guard = FETCH_RESPONSES.lock().unwrap();
-        guard.get(&id).map(|resp| {
-            if resp.body_present && resp.body_used {
-                unsafe {
-                    throw_fetch_type_error("Response.clone: Body has already been consumed.")
-                };
-            }
-            FetchResponse {
-                status: resp.status,
-                status_text: resp.status_text.clone(),
-                headers: resp.headers.clone(),
-                body: resp.body.clone(),
-                body_present: resp.body_present,
-                body_used: false,
-                type_name: resp.type_name.clone(),
-                url: resp.url.clone(),
-                redirected: resp.redirected,
-                cached_headers_id: None,
-                cached_body_stream_id: None,
-            }
-        })
-    };
-    if let Some(new_resp) = cloned {
-        let new_id = alloc_fetch_handle_id();
-        FETCH_RESPONSES.lock().unwrap().insert(new_id, new_resp);
-        return handle_to_f64(new_id);
-    }
-    f64::from_bits(TAG_UNDEFINED)
-}
-
 /// response.arrayBuffer() — returns a real BufferHeader holding the body bytes,
 /// NaN-boxed as POINTER_TAG so that `new Uint8Array(buf)` and `Buffer.from(buf)`
 /// see the actual byte contents. `.byteLength` / `.length` access routes through
@@ -1681,6 +1575,14 @@ pub unsafe extern "C" fn js_blob_stream(handle: f64) -> f64 {
 /// single stream, and a fresh one each call would silently unlock a held
 /// reader (#1650).
 fn response_body_stream(resp_id: usize) -> f64 {
+    if let Some(id) = FETCH_RESPONSES
+        .lock()
+        .unwrap()
+        .get(&resp_id)
+        .and_then(|r| r.body_stream_id)
+    {
+        return id as f64;
+    }
     if let Some(id) = FETCH_RESPONSES
         .lock()
         .unwrap()
diff --git a/crates/perry-stdlib/src/fetch/request_ctor.rs b/crates/perry-stdlib/src/fetch/request_ctor.rs
index b87792c09f..471b04c593 100644
--- a/crates/perry-stdlib/src/fetch/request_ctor.rs
+++ b/crates/perry-stdlib/src/fetch/request_ctor.rs
@@ -61,7 +61,8 @@ pub unsafe extern "C" fn js_request_new(
     // real Blob / buffer / string body is untouched. Mirrors the #5437 fix already
     // in `js_response_body_init_ptr` (the Response twin), which falls through via
     // `or_else` rather than if/else.
-    let body: Option<Vec<u8>> =
+    let pending_stream_id = take_pending_fetch_body_stream_id();
+    let non_stream_body: Option<Vec<u8>> =
         if perry_runtime::value::addr_class::is_handle_band(body_ptr as usize) {
             crate::fetch::blob_bytes_clone(body_ptr as usize)
                 .or_else(|| dispatch::incoming_message_raw_body_bytes(body_ptr as usize))
@@ -73,9 +74,14 @@ pub unsafe extern "C" fn js_request_new(
                 .or_else(|| dispatch::body_bytes_from_header(body_ptr))
         };
     // GET/HEAD requests may not carry a body (WHATWG fetch). Refs #2643.
-    if body.is_some() && (method == "GET" || method == "HEAD") {
+    if (pending_stream_id.is_some() || non_stream_body.is_some())
+        && (method == "GET" || method == "HEAD")
+    {
         throw_fetch_type_error("Request with GET/HEAD method cannot have body.");
     }
+    let body = pending_stream_id
+        .map(crate::streams::drain_readable_into_bytes)
+        .or(non_stream_body);
     let headers_id_in = handle_id(headers_handle);
     let headers = if headers_id_in != 0 {
         HEADERS_REGISTRY
diff --git a/crates/perry-stdlib/src/fetch/response_ctor.rs b/crates/perry-stdlib/src/fetch/response_ctor.rs
new file mode 100644
index 0000000000..964ebc67b8
--- /dev/null
+++ b/crates/perry-stdlib/src/fetch/response_ctor.rs
@@ -0,0 +1,156 @@
+use super::*;
+
+pub(super) fn alloc_response(
+    status: u16,
+    status_text: String,
+    headers: HeadersStore,
+    body: Vec<u8>,
+    body_present: bool,
+) -> usize {
+    let id = alloc_fetch_handle_id();
+    FETCH_RESPONSES.lock().unwrap().insert(
+        id,
+        FetchResponse {
+            status,
+            status_text,
+            headers,
+            body,
+            body_present,
+            body_used: false,
+            type_name: "default".to_string(),
+            url: String::new(),
+            redirected: false,
+            cached_headers_id: None,
+            cached_body_stream_id: None,
+            body_stream_id: None,
+        },
+    );
+    id
+}
+
+/// new Response(body, statusOpt, statusTextPtrOpt, headersHandleOpt)
+/// - body_ptr: StringHeader for the body, or null for ""
+/// - status: f64 (200 default)
+/// - status_text_ptr: StringHeader for statusText, or null for ""
+/// - headers_handle: f64 numeric handle from js_headers_new, or 0
+#[no_mangle]
+pub unsafe extern "C" fn js_response_new(
+    body_ptr: *const StringHeader,
+    status: f64,
+    status_text_ptr: *const StringHeader,
+    headers_handle: f64,
+) -> f64 {
+    let body_stream_id = take_pending_fetch_body_stream_id();
+    // Lossless raw-byte read so binary bodies survive byte-for-byte (#5435).
+    let body_opt = dispatch::body_bytes_from_header(body_ptr);
+    let body_present = body_opt.is_some() || body_stream_id.is_some();
+    let body = body_opt.unwrap_or_default();
+    // NaN / 0.0 are the codegen "no status field" sentinels. Node defaults
+    // missing status to 200; any explicit value is truncated toward zero
+    // then range-checked against 200..=599 (199.9 → RangeError, 599.9 →
+    // 599). Refs #2640.
+    let status_u16 = if status.is_nan() || status == 0.0 {
+        200
+    } else {
+        let truncated = status.trunc();
+        if !(200.0..=599.0).contains(&truncated) {
+            throw_fetch_range_error(
+                "init[\"status\"] must be in the range of 200 to 599, inclusive.",
+            );
+        }
+        truncated as u16
+    };
+    // Node defaults statusText to the empty string (NOT the canonical
+    // reason phrase) and validates the reason-phrase token. Refs #2640.
+    let status_text = match string_from_header(status_text_ptr) {
+        Some(s) => {
+            if !is_valid_status_text(&s) {
+                throw_fetch_type_error("Invalid statusText");
+            }
+            s
+        }
+        None => String::new(),
+    };
+    if body_present && is_null_body_status(status_u16) {
+        throw_fetch_type_error(&format!(
+            "Response constructor: Invalid response status code {status_u16}"
+        ));
+    }
+    let headers_id = handle_id(headers_handle);
+    let headers = if headers_id != 0 {
+        HEADERS_REGISTRY
+            .lock()
+            .unwrap()
+            .get(&headers_id)
+            .cloned()
+            .unwrap_or_default()
+    } else {
+        HeadersStore::default()
+    };
+    let id = alloc_response(status_u16, status_text, headers, body, body_present);
+    if let Some(stream_id) = body_stream_id {
+        if let Some(resp) = FETCH_RESPONSES.lock().unwrap().get_mut(&id) {
+            resp.body_stream_id = Some(stream_id);
+            resp.cached_body_stream_id = Some(stream_id);
+        }
+    }
+    handle_to_f64(id)
+}
+
+/// response.headers — returns a Headers handle (f64). Lazily allocates a Headers entry
+/// from the response's stored header HashMap if one doesn't exist yet.
+#[no_mangle]
+pub extern "C" fn js_response_get_headers(handle: f64) -> f64 {
+    let id = handle_id(handle);
+    let store = {
+        let guard = FETCH_RESPONSES.lock().unwrap();
+        match guard.get(&id) {
+            Some(resp) => resp.headers.clone(),
+            None => return f64::from_bits(TAG_UNDEFINED),
+        }
+    };
+    handle_to_f64(alloc_headers(store))
+}
+
+/// response.clone() — duplicates the response (deep copy of body + headers)
+#[no_mangle]
+pub extern "C" fn js_response_clone(handle: f64) -> f64 {
+    let id = handle_id(handle);
+    let cloned = {
+        let mut guard = FETCH_RESPONSES.lock().unwrap();
+        guard.get_mut(&id).map(|resp| {
+            if resp.body_present && resp.body_used {
+                unsafe {
+                    throw_fetch_type_error("Response.clone: Body has already been consumed.")
+                };
+            }
+            let cloned_stream_id = resp.body_stream_id.map(|stream_id| {
+                let (original, cloned) =
+                    unsafe { crate::streams::tee_readable_stream_ids(stream_id) };
+                resp.body_stream_id = Some(original);
+                resp.cached_body_stream_id = Some(original);
+                cloned
+            });
+            FetchResponse {
+                status: resp.status,
+                status_text: resp.status_text.clone(),
+                headers: resp.headers.clone(),
+                body: resp.body.clone(),
+                body_present: resp.body_present,
+                body_used: false,
+                type_name: resp.type_name.clone(),
+                url: resp.url.clone(),
+                redirected: resp.redirected,
+                cached_headers_id: None,
+                cached_body_stream_id: cloned_stream_id,
+                body_stream_id: cloned_stream_id,
+            }
+        })
+    };
+    if let Some(new_resp) = cloned {
+        let new_id = alloc_fetch_handle_id();
+        FETCH_RESPONSES.lock().unwrap().insert(new_id, new_resp);
+        return handle_to_f64(new_id);
+    }
+    f64::from_bits(TAG_UNDEFINED)
+}
diff --git a/crates/perry-stdlib/src/streams.rs b/crates/perry-stdlib/src/streams.rs
index c1f61684bc..2099457f0e 100644
--- a/crates/perry-stdlib/src/streams.rs
+++ b/crates/perry-stdlib/src/streams.rs
@@ -98,6 +98,7 @@ mod transform;
 mod writable;
 
 pub use tee::js_readable_stream_tee;
+pub(crate) use tee::tee_readable_stream_ids;
 use tee::{tee_branches_of, tee_error_branches, tee_source_of};
 
 pub use self::byob::{
diff --git a/crates/perry-stdlib/src/streams/tee.rs b/crates/perry-stdlib/src/streams/tee.rs
index 323a41125b..69f090d507 100644
--- a/crates/perry-stdlib/src/streams/tee.rs
+++ b/crates/perry-stdlib/src/streams/tee.rs
@@ -453,9 +453,7 @@ extern "C" fn tee_pull_microtask(closure: *const ClosureHeader) -> f64 {
 /// previous implementation snapshot-drained the source's current buffer and
 /// closed it, which yielded two empty branches for a pull-driven source (e.g.
 /// react-server-dom's RSC flight producer, which only produces on pull) — #5989.
-#[no_mangle]
-pub unsafe extern "C" fn js_readable_stream_tee(stream_handle: f64) -> f64 {
-    let id = stream_handle as usize;
+pub(crate) unsafe fn tee_readable_stream_ids(id: usize) -> (usize, usize) {
     let mut was_locked = false;
     let mut is_byte_stream = false;
     let mut source_state = ReadableState::Readable;
@@ -549,6 +547,12 @@ pub unsafe extern "C" fn js_readable_stream_tee(stream_handle: f64) -> f64 {
         idalloc::retire_readable_terminal(id_b);
     }
 
+    (id_a, id_b)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn js_readable_stream_tee(stream_handle: f64) -> f64 {
+    let (id_a, id_b) = tee_readable_stream_ids(stream_handle as usize);
     let arr = js_array_alloc(2);
     js_array_push(arr, JSValue::from_bits(f64::to_bits(id_a as f64)));
     js_array_push(arr, JSValue::from_bits(f64::to_bits(id_b as f64)));
diff --git a/crates/perry/src/commands/compile/collect_modules.rs b/crates/perry/src/commands/compile/collect_modules.rs
index dcecd5b564..8340583463 100644
--- a/crates/perry/src/commands/compile/collect_modules.rs
+++ b/crates/perry/src/commands/compile/collect_modules.rs
@@ -1,13 +1,8 @@
 //! Module discovery + transitive import walk.
-//!
-//! Tier 2.1 follow-up (v0.5.341) — extracts `collect_modules` (~380
-//! LOC) from `compile.rs`. Walks the import graph from the entry
-//! file, lowers every TypeScript module to HIR, classifies each as
-//! native-compiled vs JS-runtime-loaded, and accumulates the result
-//! in `CompilationContext.native_modules` / `js_modules`. Runs
-//! per-module HIR passes (inline_functions, transform_generators)
-//! before adding the module to the context. Source hashes feed the
-//! V2.2 codegen cache key derivation.
+//! Walks the import graph, lowers TypeScript to HIR, classifies native-compiled
+//! versus JS-runtime-loaded modules, and accumulates them in the compilation context.
+//! Per-module HIR passes run before insertion, and source hashes feed
+//! the V2.2 codegen cache key.
 
 use anyhow::{anyhow, Result};
 use perry_hir::ModuleKind;
@@ -39,6 +34,7 @@ mod feature_detect;
 mod import_helpers;
 mod native_addon;
 mod parse_error;
+mod script_string;
 mod static_require_transform;
 #[cfg(test)]
 mod tests;
@@ -1303,6 +1299,10 @@ fn collect_module_one(
             continue;
         }
 
+        if script_string::resolve(ctx, &canonical, import, &mut pending)? {
+            continue;
+        }
+
         if let Some(resolved) =
             cached_resolve_import_with_lexical_base(&import.source, entry_path, &canonical, ctx)
         {
diff --git a/crates/perry/src/commands/compile/collect_modules/script_string.rs b/crates/perry/src/commands/compile/collect_modules/script_string.rs
new file mode 100644
index 0000000000..b6540af5e8
--- /dev/null
+++ b/crates/perry/src/commands/compile/collect_modules/script_string.rs
@@ -0,0 +1,75 @@
+//! `?script-string` asset imports used by TanStack Start's hydration bootstrap.
+
+use anyhow::{anyhow, Result};
+use perry_hir::{Import, ModuleKind};
+use std::fs;
+use std::hash::{Hash, Hasher};
+use std::path::{Path, PathBuf};
+
+use super::super::CompilationContext;
+
+fn import_target(specifier: &str) -> Option<&str> {
+    let (path, query) = specifier.split_once('?')?;
+    query
+        .split('&')
+        .any(|part| part == "script-string")
+        .then_some(path)
+}
+
+fn source_path(target: &str, importer_path: &Path) -> Option<PathBuf> {
+    if target.starts_with('/') {
+        super::super::resolve::resolve_absolute_import_paths(target).map(|path| path.canonical_path)
+    } else {
+        super::super::resolve::resolve_relative_import_path(target, importer_path)
+    }
+}
+
+/// Materialize a string asset as a synthetic TypeScript default export.
+///
+/// The source is deliberately preserved byte-for-byte. It is executable text,
+/// so whitespace trimming or inferred semicolon insertion can change its
+/// meaning. Relative targets use the current module, not the graph entry.
+pub(super) fn resolve(
+    ctx: &CompilationContext,
+    importer_path: &Path,
+    import: &mut Import,
+    pending: &mut Vec<PathBuf>,
+) -> Result<bool> {
+    let Some(target) = import_target(&import.source) else {
+        return Ok(false);
+    };
+    let Some(source_path) = source_path(target, importer_path) else {
+        return Ok(false);
+    };
+    let script = fs::read_to_string(&source_path)
+        .map_err(|e| anyhow!("Failed to read {}: {}", source_path.display(), e))?;
+    let literal = serde_json::to_string(&script).map_err(|e| {
+        anyhow!(
+            "Failed to encode script-string asset {} as a string literal: {}",
+            source_path.display(),
+            e
+        )
+    })?;
+
+    let mut hasher = std::collections::hash_map::DefaultHasher::new();
+    source_path.hash(&mut hasher);
+    import.source.hash(&mut hasher);
+    script.hash(&mut hasher);
+    let filename = format!("script-string-{:016x}.ts", hasher.finish());
+    let dir = ctx.cache_dir.join("synthetic-modules");
+    fs::create_dir_all(&dir).map_err(|e| anyhow!("Failed to create {}: {}", dir.display(), e))?;
+    let synthetic_path = dir.join(filename);
+    fs::write(&synthetic_path, format!("export default {};\n", literal))
+        .map_err(|e| anyhow!("Failed to write {}: {}", synthetic_path.display(), e))?;
+    let canonical = synthetic_path.canonicalize().map_err(|e| {
+        anyhow!(
+            "Failed to canonicalize synthetic module {}: {}",
+            synthetic_path.display(),
+            e
+        )
+    })?;
+    import.resolved_path = Some(canonical.to_string_lossy().into_owned());
+    import.module_kind = ModuleKind::NativeCompiled;
+    pending.push(synthetic_path);
+    Ok(true)
+}
diff --git a/crates/perry/src/commands/compile/resolve.rs b/crates/perry/src/commands/compile/resolve.rs
index 4a43004f35..dbcdf23be9 100644
--- a/crates/perry/src/commands/compile/resolve.rs
+++ b/crates/perry/src/commands/compile/resolve.rs
@@ -824,7 +824,11 @@ pub(super) fn resolve_package_source_entry(
         }
     }
 
-    // For subpaths, try src/<subpath>.ts
+    // For subpaths, try src/<subpath>.ts first. If that shorthand does not
+    // exist, respect package.json "exports" for the subpath before considering
+    // the package root. Falling back to src/index.ts for a subpath misroutes
+    // imports like `@tanstack/router-core/isServer` to the root barrel and
+    // leaves callers linked against symbols that the root never exports.
     if let Some(sub) = subpath {
         let src_path = package_dir.join("src").join(sub);
         if let Some(resolved) = resolve_with_extensions(&src_path) {
@@ -832,6 +836,9 @@ pub(super) fn resolve_package_source_entry(
                 return Some(resolved);
             }
         }
+
+        let normal_entry = normal_entry?;
+        return prefer_ts_source_for_package_entry(package_dir, normal_entry);
     }
 
     // Try src/index.ts (most common TS source entry)
@@ -844,24 +851,38 @@ pub(super) fn resolve_package_source_entry(
 
     // Try using normal entry resolution but prefer TS over JS
     let normal_entry = normal_entry?;
-    if is_js_file(&normal_entry) {
-        // Try .ts equivalent of the .js entry
-        let ts_path = normal_entry.with_extension("ts");
-        if ts_path.exists() && !is_hybrid_cjs_emit_input(&ts_path) {
+    prefer_ts_source_for_package_entry(package_dir, normal_entry)
+}
+
+fn prefer_ts_source_for_package_entry(
+    package_dir: &Path,
+    normal_entry: PathBuf,
+) -> Option<PathBuf> {
+    if !is_js_file(&normal_entry) {
+        return Some(normal_entry);
+    }
+
+    // Try native TypeScript equivalents of the JS entry first, in the
+    // same preference order used by resolve_with_extensions.
+    for ext in ["ts", "tsx", "mts"] {
+        let ts_path = normal_entry.with_extension(ext);
+        if ts_path.is_file() && !is_hybrid_cjs_emit_input(&ts_path) {
             return Some(ts_path);
         }
-        // Check src/ directory mirror of lib/ or dist/ path
-        if let Ok(rel) = normal_entry.strip_prefix(package_dir) {
-            let rel_str = rel.to_string_lossy();
-            if rel_str.starts_with("lib") || rel_str.starts_with("dist") {
-                let stripped = if rel_str.starts_with("lib") {
-                    rel.strip_prefix("lib")
-                } else {
-                    rel.strip_prefix("dist")
-                };
-                if let Ok(rest) = stripped {
-                    let src_equiv = package_dir.join("src").join(rest).with_extension("ts");
-                    if src_equiv.exists() && !is_hybrid_cjs_emit_input(&src_equiv) {
+    }
+    // Check src/ directory mirror of lib/ or dist/ path
+    if let Ok(rel) = normal_entry.strip_prefix(package_dir) {
+        let rel_str = rel.to_string_lossy();
+        if rel_str.starts_with("lib") || rel_str.starts_with("dist") {
+            let stripped = if rel_str.starts_with("lib") {
+                rel.strip_prefix("lib")
+            } else {
+                rel.strip_prefix("dist")
+            };
+            if let Ok(rest) = stripped {
+                for ext in ["ts", "tsx", "mts"] {
+                    let src_equiv = package_dir.join("src").join(rest).with_extension(ext);
+                    if src_equiv.is_file() && !is_hybrid_cjs_emit_input(&src_equiv) {
                         return Some(src_equiv);
                     }
                 }
diff --git a/crates/perry/src/commands/compile/resolve/tests.rs b/crates/perry/src/commands/compile/resolve/tests.rs
index bfd18d7c77..95ed9c0792 100644
--- a/crates/perry/src/commands/compile/resolve/tests.rs
+++ b/crates/perry/src/commands/compile/resolve/tests.rs
@@ -1452,6 +1452,8 @@ mod declaration_sidecar_tests {
     use super::*;
     use std::collections::{HashMap, HashSet};
 
+    mod compile_package;
+
     fn write_typed_js_package(root: &Path, package_name: &str) -> (PathBuf, PathBuf, PathBuf) {
         let package_dir = root.join("node_modules").join(package_name);
         std::fs::create_dir_all(package_dir.join("dist")).expect("mkdir package dist");
@@ -1559,35 +1561,6 @@ mod declaration_sidecar_tests {
         );
     }
 
-    #[test]
-    fn extract_compile_package_dir_uses_path_components() {
-        let dir = tempfile::tempdir().expect("tempdir");
-        let root = dir.path();
-        let path = root
-            .join("node_modules")
-            .join("@noble")
-            .join("curves")
-            .join("node_modules")
-            .join("@noble")
-            .join("hashes")
-            .join("src")
-            .join("sha256.ts");
-
-        assert_eq!(
-            extract_compile_package_dir(&path, "@noble/hashes").expect("package dir"),
-            root.join("node_modules")
-                .join("@noble")
-                .join("curves")
-                .join("node_modules")
-                .join("@noble")
-                .join("hashes")
-        );
-        assert_eq!(
-            extract_compile_package_dir(&path, "@noble/curves").expect("outer package dir"),
-            root.join("node_modules").join("@noble").join("curves")
-        );
-    }
-
     #[test]
     fn compile_package_membership_uses_path_components() {
         let dir = tempfile::tempdir().expect("tempdir");
diff --git a/crates/perry/src/commands/compile/resolve/tests/declaration_sidecar_tests/compile_package.rs b/crates/perry/src/commands/compile/resolve/tests/declaration_sidecar_tests/compile_package.rs
new file mode 100644
index 0000000000..e813826dd1
--- /dev/null
+++ b/crates/perry/src/commands/compile/resolve/tests/declaration_sidecar_tests/compile_package.rs
@@ -0,0 +1,84 @@
+use super::*;
+
+#[test]
+fn subpath_exports_do_not_fall_back_to_src_index() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let root = dir.path();
+    let package_dir = root.join("node_modules").join("pkg");
+    std::fs::create_dir_all(package_dir.join("src/feature")).expect("mkdir package");
+    std::fs::write(
+        package_dir.join("package.json"),
+        r#"{
+          "name": "pkg",
+          "type": "module",
+          "exports": {
+            ".": { "import": { "default": "./src/index.ts" } },
+            "./feature": { "import": { "default": "./src/feature/server.ts" } }
+          }
+        }"#,
+    )
+    .expect("write package.json");
+    std::fs::write(
+        package_dir.join("src/index.ts"),
+        "export const rootOnly = 1;\n",
+    )
+    .expect("write root");
+    std::fs::write(
+        package_dir.join("src/feature/server.ts"),
+        "export const subValue = 41;\n",
+    )
+    .expect("write subpath");
+
+    let importer_dir = root.join("src");
+    std::fs::create_dir_all(&importer_dir).expect("mkdir src");
+    let importer = importer_dir.join("main.ts");
+    std::fs::write(&importer, "import { subValue } from 'pkg/feature';\n").expect("write importer");
+
+    let compile_packages = HashSet::from(["pkg".to_string()]);
+    let resolved = resolve_import(
+        "pkg/feature",
+        &importer,
+        root,
+        &compile_packages,
+        &HashMap::new(),
+    )
+    .expect("resolve pkg/feature");
+
+    assert_eq!(resolved.1, ModuleKind::NativeCompiled);
+    assert_eq!(
+        resolved.0,
+        package_dir
+            .join("src/feature/server.ts")
+            .canonicalize()
+            .expect("canonical subpath")
+    );
+}
+
+#[test]
+fn compile_package_dir_uses_path_components() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let root = dir.path();
+    let path = root
+        .join("node_modules")
+        .join("@noble")
+        .join("curves")
+        .join("node_modules")
+        .join("@noble")
+        .join("hashes")
+        .join("src")
+        .join("sha256.ts");
+
+    assert_eq!(
+        extract_compile_package_dir(&path, "@noble/hashes").expect("package dir"),
+        root.join("node_modules")
+            .join("@noble")
+            .join("curves")
+            .join("node_modules")
+            .join("@noble")
+            .join("hashes")
+    );
+    assert_eq!(
+        extract_compile_package_dir(&path, "@noble/curves").expect("outer package dir"),
+        root.join("node_modules").join("@noble").join("curves")
+    );
+}
diff --git a/crates/perry/src/commands/compile/run_pipeline.rs b/crates/perry/src/commands/compile/run_pipeline.rs
index e0161e2108..677ef4563b 100644
--- a/crates/perry/src/commands/compile/run_pipeline.rs
+++ b/crates/perry/src/commands/compile/run_pipeline.rs
@@ -3343,7 +3343,10 @@ pub fn run_with_parse_cache(
                     let origin_key_under_origin_name = resolved_origin_name
                         .as_ref()
                         .map(|n| (origin_path.clone(), n.clone()));
-                    if exported_var_names.contains(&origin_key)
+                    let source_exports_object =
+                        exported_var_names.contains(&(resolved_path_str.clone(), exported_name.clone()));
+                    if source_exports_object
+                        || exported_var_names.contains(&origin_key)
                         || origin_key_under_origin_name
                             .as_ref()
                             .map(|k| exported_var_names.contains(k))
diff --git a/crates/perry/tests/issue_5756_response_stream_body.rs b/crates/perry/tests/issue_5756_response_stream_body.rs
new file mode 100644
index 0000000000..0df5877942
--- /dev/null
+++ b/crates/perry/tests/issue_5756_response_stream_body.rs
@@ -0,0 +1,338 @@
+//! Regression coverage for TanStack Start SSR streaming through Response
+//! wrappers. The app path constructs `Response(ReadableStream)` values whose
+//! chunks are produced lazily from downstream pulls; eagerly draining only
+//! already-buffered chunks turns a valid HTML response into an empty body.
+
+use std::path::PathBuf;
+use std::process::Command;
+
+fn perry_bin() -> PathBuf {
+    PathBuf::from(env!("CARGO_BIN_EXE_perry"))
+}
+
+fn compile_and_run(dir: &std::path::Path, source: &str) -> String {
+    let entry = dir.join("main.js");
+    let output = dir.join("main_bin");
+    std::fs::write(&entry, source).expect("write entry");
+
+    let compile = Command::new(perry_bin())
+        .current_dir(dir)
+        .arg("compile")
+        .arg(&entry)
+        .arg("-o")
+        .arg(&output)
+        .output()
+        .expect("run perry compile");
+    assert!(
+        compile.status.success(),
+        "perry compile failed\nstdout:\n{}\nstderr:\n{}",
+        String::from_utf8_lossy(&compile.stdout),
+        String::from_utf8_lossy(&compile.stderr)
+    );
+
+    let run = Command::new(&output)
+        .current_dir(dir)
+        .output()
+        .expect("run compiled binary");
+    assert!(
+        run.status.success(),
+        "compiled binary failed\nstatus: {:?}\nstdout:\n{}\nstderr:\n{}",
+        run.status,
+        String::from_utf8_lossy(&run.stdout),
+        String::from_utf8_lossy(&run.stderr)
+    );
+    String::from_utf8_lossy(&run.stdout).into_owned()
+}
+
+fn compile_and_run_entry(dir: &std::path::Path, entry_name: &str) -> String {
+    let entry = dir.join(entry_name);
+    let output = dir.join("main_bin");
+
+    let compile = Command::new(perry_bin())
+        .current_dir(dir)
+        .arg("compile")
+        .arg(&entry)
+        .arg("-o")
+        .arg(&output)
+        .output()
+        .expect("run perry compile");
+    assert!(
+        compile.status.success(),
+        "perry compile failed\nstdout:\n{}\nstderr:\n{}",
+        String::from_utf8_lossy(&compile.stdout),
+        String::from_utf8_lossy(&compile.stderr)
+    );
+
+    let run = Command::new(&output)
+        .current_dir(dir)
+        .output()
+        .expect("run compiled binary");
+    assert!(
+        run.status.success(),
+        "compiled binary failed\nstatus: {:?}\nstdout:\n{}\nstderr:\n{}",
+        run.status,
+        String::from_utf8_lossy(&run.stdout),
+        String::from_utf8_lossy(&run.stderr)
+    );
+    String::from_utf8_lossy(&run.stdout).into_owned()
+}
+
+#[test]
+fn response_preserves_pull_driven_readable_stream_body() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let stdout = compile_and_run(
+        dir.path(),
+        r#"
+const enc = new TextEncoder()
+let pulls = 0
+const stream = new ReadableStream({
+  pull(controller) {
+    pulls++
+    controller.enqueue(enc.encode('hello'))
+    controller.close()
+  }
+})
+const response = new Response(stream, { status: 200 })
+const reader = response.body.getReader()
+const first = await reader.read()
+console.log('done=' + first.done + ',len=' + (first.value ? first.value.byteLength : 0) + ',pulls=' + pulls)
+"#,
+    );
+    assert_eq!(stdout, "done=false,len=5,pulls=1\n");
+}
+
+#[test]
+fn response_clone_tees_pull_driven_stream_body() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let stdout = compile_and_run(
+        dir.path(),
+        r#"
+const enc = new TextEncoder()
+let pulls = 0
+const response = new Response(new ReadableStream({
+  pull(controller) {
+    pulls++
+    controller.enqueue(enc.encode('hello'))
+    controller.close()
+  }
+}))
+const clone = response.clone()
+const originalRead = await response.body.getReader().read()
+const cloneRead = await clone.body.getReader().read()
+console.log(originalRead.value.byteLength + ',' + cloneRead.value.byteLength + ',' + pulls)
+"#,
+    );
+    assert_eq!(stdout, "5,5,1\n");
+}
+
+#[test]
+fn request_rejects_get_stream_body_without_pulling_it() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let stdout = compile_and_run(
+        dir.path(),
+        r#"
+let pulls = 0
+const body = new ReadableStream({ pull() { pulls++ } })
+try {
+  new Request('https://example.test/', { method: 'GET', body, duplex: 'half' })
+  console.log('did-not-throw')
+} catch (error) {
+  console.log((error instanceof TypeError) + ',' + pulls)
+}
+"#,
+    );
+    assert_eq!(stdout, "true,0\n");
+}
+
+#[test]
+fn response_prototype_exposes_fetch_accessors_for_wrappers() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let stdout = compile_and_run(
+        dir.path(),
+        r#"
+const names = Object.getOwnPropertyNames(Response.prototype)
+const body = Object.getOwnPropertyDescriptor(Response.prototype, 'body')
+const headers = Object.getOwnPropertyDescriptor(Response.prototype, 'headers')
+console.log(names.includes('body') + ',' + (typeof body?.get) + ',' + names.includes('headers') + ',' + (typeof headers?.get))
+"#,
+    );
+    assert_eq!(stdout, "true,function,true,function\n");
+}
+
+#[test]
+fn dynamic_import_inside_arrow_closure_is_collected() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(
+        dir.path().join("main.js"),
+        r#"
+const importer = () => import('./lazy.js')
+const mod = await importer()
+console.log('answer=' + mod.answer)
+"#,
+    )
+    .expect("write main");
+    std::fs::write(dir.path().join("lazy.js"), "export const answer = 42\n").expect("write lazy");
+    let stdout = compile_and_run_entry(dir.path(), "main.js");
+    assert_eq!(stdout, "answer=42\n");
+}
+
+#[test]
+fn script_string_query_imports_compile_to_default_string_asset() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(
+        dir.path().join("package.json"),
+        r#"{
+          "type": "module",
+          "perry": {
+            "compilePackages": ["pkg"],
+            "allow": { "compilePackages": ["pkg"] }
+          }
+        }"#,
+    )
+    .expect("write package");
+    let pkg = dir.path().join("node_modules/pkg");
+    std::fs::create_dir_all(pkg.join("src")).expect("mkdir pkg");
+    std::fs::write(
+        pkg.join("package.json"),
+        r#"{
+          "name": "pkg",
+          "type": "module",
+          "exports": { ".": { "import": { "default": "./src/index.ts" } } }
+        }"#,
+    )
+    .expect("write pkg package");
+    std::fs::write(
+        pkg.join("src/index.ts"),
+        "import boot from './boot?script-string'\nexport function readBoot() { return boot }\n",
+    )
+    .expect("write pkg index");
+    std::fs::write(
+        pkg.join("src/boot.ts"),
+        "// preserve formatting\nself.$_TSR = {\n  buffer: []\n}\n",
+    )
+    .expect("write script source");
+    std::fs::write(
+        dir.path().join("main.js"),
+        "import { readBoot } from 'pkg'\nconst boot = readBoot()\nconsole.log(typeof boot)\nconsole.log(boot.includes('self.$_TSR ='))\nconsole.log(JSON.stringify(boot))\n",
+    )
+    .expect("write main");
+
+    let stdout = compile_and_run_entry(dir.path(), "main.js");
+    assert_eq!(
+        stdout,
+        "string\ntrue\n\"// preserve formatting\\nself.$_TSR = {\\n  buffer: []\\n}\\n\"\n"
+    );
+}
+
+#[test]
+fn map_foreach_property_receiver_preserves_map_callback_shape() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let stdout = compile_and_run(
+        dir.path(),
+        r#"
+const renderState = { styles: new Map() }
+renderState.styles.set('default', {
+  precedence: 'default',
+  sheets: new Map([['/assets/styles.css', { href: '/assets/styles.css' }]])
+})
+const seen = []
+renderState.styles.forEach(function(styleQueue, key, map) {
+  seen.push(
+    key + ':' +
+    styleQueue.precedence + ':' +
+    styleQueue.sheets.size + ':' +
+    (map === renderState.styles) + ':' +
+    this.destination
+  )
+}, { destination: 'html' })
+console.log(seen.join('|'))
+"#,
+    );
+    assert_eq!(stdout, "default:default:1:true:html\n");
+}
+
+#[test]
+fn imported_jsx_named_function_remains_an_import_binding() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(
+        dir.path().join("main.js"),
+        "import { jsx } from './jsx-lib.js'\nconsole.log(jsx('value'))\n",
+    )
+    .expect("write main");
+    std::fs::write(
+        dir.path().join("jsx-lib.js"),
+        "export function jsx(value) { return 'imported:' + value }\n",
+    )
+    .expect("write lib");
+
+    let stdout = compile_and_run_entry(dir.path(), "main.js");
+    assert_eq!(stdout, "imported:value\n");
+}
+
+#[test]
+fn react_type_only_import_does_not_disable_automatic_jsx_runtime_binding() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(
+        dir.path().join("package.json"),
+        r#"{
+          "type": "module",
+          "perry": {
+            "compilePackages": ["react", "@tanstack/react-router"],
+            "allow": { "compilePackages": ["react", "@tanstack/react-router"] }
+          }
+        }"#,
+    )
+    .expect("write package");
+    let react = dir.path().join("node_modules/react");
+    std::fs::create_dir_all(&react).expect("mkdir react");
+    std::fs::write(
+        react.join("package.json"),
+        r#"{"name":"react","type":"module","exports":{".":"./index.js"}}"#,
+    )
+    .expect("write react package");
+    std::fs::write(
+        react.join("index.js"),
+        "export function createElement(type, props, ...children) { return 'react:' + type + ':' + children.join('|') }\n",
+    )
+    .expect("write react index");
+    let router = dir.path().join("node_modules/@tanstack/react-router");
+    std::fs::create_dir_all(&router).expect("mkdir router");
+    std::fs::write(
+        router.join("package.json"),
+        r#"{"name":"@tanstack/react-router","type":"module","exports":{".":"./index.js"}}"#,
+    )
+    .expect("write router package");
+    std::fs::write(router.join("index.js"), "export const Link = 'link'\n")
+        .expect("write router index");
+    std::fs::write(
+        dir.path().join("main.tsx"),
+        r#"
+import type * as React from 'react'
+import { Link } from '@tanstack/react-router'
+function App() { return <div>Hello</div> }
+console.log(App())
+"#,
+    )
+    .expect("write main");
+
+    let stdout = compile_and_run_entry(dir.path(), "main.tsx");
+    assert_eq!(stdout, "react:div:\n");
+}
+
+#[test]
+fn named_imported_exported_function_as_value_stays_callable() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(
+        dir.path().join("main.js"),
+        "import { callMe } from './lib.js'\nconst fn = callMe\nconsole.log(fn('x'))\n",
+    )
+    .expect("write main");
+    std::fs::write(
+        dir.path().join("lib.js"),
+        "export function callMe(value) { return 'fn:' + value }\n",
+    )
+    .expect("write lib");
+
+    let stdout = compile_and_run_entry(dir.path(), "main.js");
+    assert_eq!(stdout, "fn:x\n");
+}
diff --git a/tests/test_compile_package_exports_subpath_source.sh b/tests/test_compile_package_exports_subpath_source.sh
new file mode 100755
index 0000000000..7375e33638
--- /dev/null
+++ b/tests/test_compile_package_exports_subpath_source.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+# Regression: compilePackages subpath exports must resolve to the subpath's
+# declared source entry, not fall back to the package root src/index.ts.
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+PERRY="${PERRY_BIN:-$SCRIPT_DIR/../target/release/perry}"
+[ ! -x "$PERRY" ] && PERRY="$SCRIPT_DIR/../target/debug/perry"
+if [ ! -x "$PERRY" ]; then
+  echo "SKIP: perry binary not found (build with cargo build --release)"
+  exit 0
+fi
+
+TMPDIR=$(mktemp -d)
+trap "rm -rf $TMPDIR" EXIT
+
+PKG="$TMPDIR/node_modules/pkg"
+CONSUMER="$TMPDIR/node_modules/consumer"
+mkdir -p "$PKG/dist/feature" "$PKG/src/feature" "$CONSUMER/src"
+
+cat > "$TMPDIR/package.json" << 'JSON'
+{
+  "type": "module",
+  "perry": {
+    "compilePackages": ["pkg", "consumer"],
+    "allow": { "compilePackages": ["pkg", "consumer"] }
+  }
+}
+JSON
+
+cat > "$TMPDIR/main.ts" << 'TS'
+import { run } from 'consumer'
+console.log('value=' + run())
+TS
+
+cat > "$PKG/package.json" << 'JSON'
+{
+  "name": "pkg",
+  "type": "module",
+  "exports": {
+    ".": { "import": { "default": "./src/index.ts" } },
+    "./feature": { "import": { "default": "./dist/feature/server.js" } }
+  }
+}
+JSON
+
+cat > "$PKG/src/index.ts" << 'TS'
+export const rootOnly = 1
+TS
+
+cat > "$PKG/dist/feature/server.js" << 'JS'
+export const subValue = 0
+JS
+
+cat > "$PKG/src/feature/server.tsx" << 'TS'
+export const subValue = 41
+TS
+
+cat > "$CONSUMER/package.json" << 'JSON'
+{
+  "name": "consumer",
+  "type": "module",
+  "exports": {
+    ".": { "import": { "default": "./src/index.ts" } }
+  },
+  "dependencies": {
+    "pkg": "1.0.0"
+  }
+}
+JSON
+
+cat > "$CONSUMER/src/index.ts" << 'TS'
+import { subValue } from 'pkg/feature'
+export function run() { return subValue + 1 }
+TS
+
+cd "$TMPDIR"
+COMPILE_OUTPUT=$("$PERRY" compile --no-cache main.ts -o out 2>&1) || {
+  echo "FAIL: compile error"
+  echo "$COMPILE_OUTPUT" | tail -40
+  exit 1
+}
+
+RUN_OUTPUT=$(./out 2>&1)
+if [ "$RUN_OUTPUT" = "value=42" ]; then
+  echo "PASS"
+  exit 0
+fi
+
+echo "FAIL: package subpath exports output mismatch"
+echo "Expected: value=42"
+echo "Got:      $RUN_OUTPUT"
+exit 1
diff --git a/tests/test_textencoder_hoisted_function_decl.sh b/tests/test_textencoder_hoisted_function_decl.sh
new file mode 100755
index 0000000000..f34cfe68e2
--- /dev/null
+++ b/tests/test_textencoder_hoisted_function_decl.sh
@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+PERRY="${PERRY_BIN:-${PERRY:-$REPO_ROOT/target/release/perry}}"
+if [[ ! -x "$PERRY" ]]; then
+  PERRY="$REPO_ROOT/target/debug/perry"
+fi
+if [[ ! -x "$PERRY" ]]; then
+  echo "Perry binary not found; run cargo build -p perry first" >&2
+  exit 1
+fi
+
+TMPDIR="$(mktemp -d)"
+trap 'rm -rf "$TMPDIR"' EXIT
+
+cat > "$TMPDIR/main.js" <<'JS'
+var util = require('util')
+
+function encodeLength(content) {
+  content = textEncoder.encode(content)
+  return content.byteLength
+}
+
+var textEncoder = new util.TextEncoder()
+
+var nestedLen = (function () {
+  function encodeLengthNested(content) {
+    content = nestedTextEncoder.encode(content)
+    return content.byteLength
+  }
+
+  var nestedTextEncoder = new util.TextEncoder()
+  return encodeLengthNested('world')
+})()
+
+console.log('len=' + encodeLength('hello') + ',nested=' + nestedLen)
+JS
+
+"$PERRY" compile --no-cache "$TMPDIR/main.js" -o "$TMPDIR/out" >"$TMPDIR/compile.log" 2>&1 || {
+  cat "$TMPDIR/compile.log" >&2
+  exit 1
+}
+
+output="$($TMPDIR/out)"
+if [[ "$output" != "len=5,nested=5" ]]; then
+  echo "Unexpected output: $output" >&2
+  exit 1
+fi