chore(webapp,core): remove v3 (engine V1) execution code

v3 (engine V1) is end-of-life. This removes the V1 execution stack while keeping
every still-on-v3 request on a graceful 4xx path (never a 5xx):

- the MarQS queue and its shared/dev queue consumers
- the V1 socket.io namespaces (coordinator, provider, shared-queue) and the V1
  attempt, checkpoint, and batch-resume lifecycle services
- the graphile-worker / zod-worker background job stack
- the DEPRECATE_V3_ENABLED flag (V1 is now rejected unconditionally) and the
  @trigger.dev/core v3/zodNamespace export

Live queue reads (concurrency limits, env queue length, project metrics, admin
queue debug) now read from the v2 run engine instead of MarQS. The batchTriggerV3
service and batch-completion worker stay live for current clients. A fresh dev
environment now defaults to V2.

Author: ericallam

.changeset/retire-v3-zod-namespace.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/core": patch
+---
+
+Removed the unused `@trigger.dev/core/v3/zodNamespace` export, which was only used by the retired v3 engine.

.claude/rules/legacy-v3-code.md

@@ -3,31 +3,24 @@ paths:
   - "apps/webapp/app/v3/**"
 ---
 
-# Legacy V1 Engine Code in `app/v3/`
+# v3 (engine V1) has been removed
 
-The `v3/` directory name is misleading - most code here is actively used by the current V2 engine. Only the specific files below are legacy V1-only code.
+The v3 engine (RunEngineVersion `V1`: MarQS queue + Graphile worker) is end-of-life and its execution code has been removed from the webapp. The `app/v3/` directory name is historical: everything under it now serves the current V2 engine (`@internal/run-engine` + `@trigger.dev/redis-worker`).
 
-## V1-Only Files - Never Modify
+There is no `V1` execution path anymore. If you find a `RunEngineVersion` branch, the `V1` arm should only ever produce a graceful rejection, never run work. Do not reintroduce MarQS, the graphile worker, or the v3 socket.io namespaces.
 
-- `marqs/` directory (entire MarQS queue system: sharedQueueConsumer, devQueueConsumer, fairDequeuingStrategy, devPubSub)
-- `legacyRunEngineWorker.server.ts` (V1 background job worker)
-- `services/triggerTaskV1.server.ts` (deprecated V1 task triggering)
-- `services/cancelTaskRunV1.server.ts` (deprecated V1 cancellation)
-- `authenticatedSocketConnection.server.ts` (V1 dev WebSocket using DevQueueConsumer)
-- `sharedSocketConnection.ts` (V1 shared queue socket using SharedQueueConsumer)
+## The deprecation boundary (keep this)
 
-## V1/V2 Branching Pattern
+Requests from clients still on v3 (old SDK/CLI) or historical V1 runs must return a clean 4xx, never a 5xx. The boundary lives in:
 
-Some services act as routers that branch on `RunEngineVersion`:
-- `services/cancelTaskRun.server.ts` - calls V1 service or `engine.cancelRun()` for V2
-- `services/batchTriggerV3.server.ts` - uses marqs for V1 path, run-engine for V2
+- `engineDeprecation.server.ts` - the `V3_TRIGGER_DEPRECATION_MESSAGE` / `V3_DEV_DEPRECATION_MESSAGE` / `V3_MIGRATION_URL` upgrade messages.
+- `engineVersion.server.ts` - `determineEngineVersion()` still detects a V1 project/run so callers can reject it.
+- `services/triggerTask.server.ts`, `services/cancelTaskRun.server.ts`, `services/rescheduleTaskRun.server.ts` - the `V1` arm rejects or finalizes gracefully instead of executing.
+- `services/initializeDeployment.server.ts` - the `DEPRECATE_V3_CLI_DEPLOYS_ENABLED`-gated v3 CLI deploy rejection.
+- `handleWebsockets.server.ts` - the legacy `trigger dev` websocket closes with the upgrade message.
 
-When editing these shared services, only modify V2 code paths.
+## V2 modern stack
 
-## V2 Modern Stack
-
-- **Run lifecycle**: `@internal/run-engine` (internal-packages/run-engine)
-- **Background jobs**: `@trigger.dev/redis-worker` (not graphile-worker/zodworker)
-- **Queue operations**: RunQueue inside run-engine (not MarQS)
-- **V2 engine singleton**: `runEngine.server.ts`, `runEngineHandlers.server.ts`
-- **V2 workers**: `commonWorker.server.ts`, `alertsWorker.server.ts`, `batchTriggerWorker.server.ts`
+- **Run lifecycle**: `@internal/run-engine` (`runEngine.server.ts`, `runEngineHandlers.server.ts`)
+- **Background jobs**: `@trigger.dev/redis-worker` (`commonWorker.server.ts`, `alertsWorker.server.ts`, `batchTriggerWorker.server.ts`; `legacyRunEngineWorker.server.ts` still hosts the live batch-completion jobs)
+- **Queue operations**: RunQueue inside run-engine (`runQueue.server.ts`), not MarQS

.server-changes/remove-v3-engine.md

@@ -0,0 +1,6 @@
+---
+area: webapp
+type: breaking
+---
+
+Removed support for the end-of-life v3 engine. Instances or projects still on v3 must stay on the 4.5.x release line or upgrade to v4; v3 triggers, batch triggers, reschedules, and deploys now return a clear upgrade message instead of running.

apps/webapp/app/components/admin/debugRun.tsx

@@ -104,7 +104,7 @@ function DebugRunDataEngineV2({
   envConcurrencyLimit,
   envCurrentConcurrency,
   keys,
-}: UseDataFunctionReturn<typeof loader>) {
+}: Extract<UseDataFunctionReturn<typeof loader>, { engine: "V2" }>) {
   return (
     <Property.Table>
       <Property.Item>

apps/webapp/app/entry.server.tsx

@@ -7,7 +7,6 @@ import { parseAcceptLanguage } from "intl-parse-accept-language";
 import isbot from "isbot";
 import { renderToPipeableStream } from "react-dom/server";
 import { PassThrough } from "stream";
-import * as Worker from "~/services/worker.server";
 import { initMollifierDrainerWorker } from "~/v3/mollifierDrainerWorker.server";
 import { initMollifierStaleSweepWorker } from "~/v3/mollifierStaleSweepWorker.server";
 import { initBillingLimitWorker } from "~/v3/billingLimitWorker.server";
@@ -227,10 +226,6 @@ export const handleError = wrapHandleErrorWithSentry((error, { request }) => {
   }
 });
 
-Worker.init().catch((error) => {
-  logError(error);
-});
-
 initMollifierDrainerWorker();
 initMollifierStaleSweepWorker();
 initBillingLimitWorker();
@@ -241,10 +236,6 @@ bootstrap().catch((error) => {
 
 function logError(error: unknown, request?: Request) {
   console.error(error);
-
-  if (error instanceof Error && error.message.startsWith("There are locked jobs present")) {
-    console.log("⚠️  graphile-worker migration issue detected!");
-  }
 }
 
 process.on("uncaughtException", (error, origin) => {

apps/webapp/app/env.server.ts

@@ -224,9 +224,6 @@ const EnvironmentSchema = z
     PLAIN_CUSTOMER_CARDS_SECRET: z.string().optional(),
     PLAIN_CUSTOMER_CARDS_KEY: z.string().optional(),
     PLAIN_CUSTOMER_CARDS_HEADERS: z.string().optional(),
-    WORKER_SCHEMA: z.string().default("graphile_worker"),
-    WORKER_CONCURRENCY: z.coerce.number().int().default(10),
-    WORKER_POLL_INTERVAL: z.coerce.number().int().default(1000),
     // How often each replica reloads the global flags snapshot from the DB.
     // Sets kill/ramp propagation latency.
     GLOBAL_FLAGS_RELOAD_INTERVAL_MS: z.coerce.number().int().min(1000).default(5000),
@@ -528,9 +525,6 @@ const EnvironmentSchema = z
     API_RATE_LIMIT_JWT_WINDOW: z.string().default("1m"),
     API_RATE_LIMIT_JWT_TOKENS: z.coerce.number().int().default(60),
 
-    //v3
-    PROVIDER_SECRET: z.string().default("provider-secret"),
-    COORDINATOR_SECRET: z.string().default("coordinator-secret"),
     DEPOT_TOKEN: z.string().optional(),
     DEPOT_ORG_ID: z.string().optional(),
     DEPOT_REGION: z.string().default("us-east-1"),
@@ -618,15 +612,6 @@ const EnvironmentSchema = z
     // log-only mode before enforcement.
     DEPRECATE_V3_CLI_DEPLOYS_ENABLED: z.string().default("0"),
 
-    // Master switch for the v3 engine (RunEngineVersion.V1) shutdown. When
-    // enabled it: rejects triggers that resolve to V1 (single, batch, schedule,
-    // replay, triggerAndWait) with a graceful error pointing at the v4 migration
-    // guide; closes the legacy `trigger dev` websocket used by v3 CLIs; and turns
-    // the V1 run-lifecycle background jobs (heartbeat timeout, TTL expiry, retry,
-    // resume, scheduled fires) into no-ops so abandoned V1 runs stop generating
-    // database load. v4 (V2) is never affected (every gate also checks the run is
-    // V1). Defaults to off so self-hosted instances still on V1 keep working.
-    DEPRECATE_V3_ENABLED: z.string().default("0"),
 
     // Verify the deploy image exists before promoting. Disable for out-of-band/air-gapped push. ECR only.
     DEPLOY_IMAGE_VERIFICATION_ENABLED: BoolEnv.default(true),
@@ -815,7 +800,6 @@ const EnvironmentSchema = z
 
     PROD_TASK_HEARTBEAT_INTERVAL_MS: z.coerce.number().int().optional(),
 
-    VERBOSE_GRAPHILE_LOGGING: z.string().default("false"),
     V2_MARQS_ENABLED: z.string().default("0"),
     V2_MARQS_CONSUMER_POOL_ENABLED: z.string().default("0"),
     V2_MARQS_CONSUMER_POOL_SIZE: z.coerce.number().int().default(10),

apps/webapp/app/routes/admin.concurrency.tsx

@@ -1,7 +1,6 @@
 import { parseWithZod } from "@conform-to/zod";
 import type { ActionFunction } from "@remix-run/node";
 import { json } from "@remix-run/node";
-import { assertExhaustive } from "@trigger.dev/core/utils";
 import { z } from "zod";
 import { prisma } from "~/db.server";
 import { redirectWithErrorMessage, redirectWithSuccessMessage } from "~/models/message.server";
@@ -10,7 +9,7 @@ import { requireUserId } from "~/services/session.server";
 import { sanitizeRedirectPath } from "~/utils";
 import { runStore } from "~/v3/runStore.server";
 import { findBatchRunIdForUser } from "~/v3/services/batchRunAccess.server";
-import { ResumeBatchRunService } from "~/v3/services/resumeBatchRun.server";
+import { tryCompleteBatchV3 } from "~/v3/services/batchTriggerV3.server";
 
 export const checkCompletionSchema = z.object({
   redirectUrl: z.string(),
@@ -44,35 +43,10 @@ export const action: ActionFunction = async ({ request, params }) => {
   }
 
   try {
-    const resumeBatchRunService = new ResumeBatchRunService();
-    // Resume by the resolved internal id: the service looks up strictly by
-    // `{ id }`, so passing a friendlyId param would resolve to nothing.
-    const resumeResult = await resumeBatchRunService.call(ownedBatchRunId);
+    // v3 (engine V1) is retired; finalize the batch through the v2 completion path (no-op if not ready).
+    await tryCompleteBatchV3(ownedBatchRunId, prisma, true);
 
-    let message: string | undefined;
-
-    switch (resumeResult) {
-      case "ERROR": {
-        throw "Unknown error during batch completion check";
-      }
-      case "ALREADY_COMPLETED": {
-        message = "Batch already completed.";
-        break;
-      }
-      case "COMPLETED": {
-        message = "Batch completed and parent tasks resumed.";
-        break;
-      }
-      case "PENDING": {
-        message = "Child runs still in progress. Please try again later.";
-        break;
-      }
-      default: {
-        assertExhaustive(resumeResult);
-      }
-    }
-
-    return redirectWithSuccessMessage(safeRedirectUrl, request, message);
+    return redirectWithSuccessMessage(safeRedirectUrl, request, "Batch completion checked.");
   } catch (error) {
     if (error instanceof Error) {
       logger.error("Failed to check batch completion", {

apps/webapp/app/routes/api.v1.runs.$runParam.attempts.ts

@@ -118,7 +118,7 @@ export async function loader({ request, params }: LoaderFunctionArgs) {
     ];
 
     return typedjson({
-      engine: "V2",
+      engine: "V2" as const,
       run,
       environment,
       queueConcurrencyLimit,