feat(anthropic_official): support Claude Haiku 5.5

changelog/unreleased/2026-10-09-claude-haiku-5-5.md

@@ -0,0 +1,18 @@
+# Support Claude Haiku 5.5
+
+- **Date:** 2026-10-09
+- **Type:** feature
+- **Scope:** `anthropic_official`, `registry`
+- **PR:** [#249](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/249)
+
+[中文版](2026-10-09-claude-haiku-5-5.zh.md)
+
+## What changed
+
+- `anthropic-official` serves `claude-haiku-5-5`, matched by version on every platform, Bedrock's `anthropic.` prefix included:
+  - `thinking_level="none"` sends adaptive thinking at `low` effort, as on Opus 5.5 and Fable 5.1, and the other levels send the effort of the same name.
+  - `tool_choice="required"` and a list of tool names raise `UnsupportedParameterError`, as on Opus 5.5 and Sonnet 5.5.
+  - `fast_mode` raises `UnsupportedParameterError`.
+- `list_supported_models` lists `claude-haiku-5-5` at $0.10 / $0.50 per million tokens with cache reads at $0.01, the price for prompts up to 100K tokens (every rate is 5x above it), and OpenRouter's `anthropic/claude-haiku-5.5` at the same prices. Cache reads on `claude-sonnet-5-5` and `anthropic/claude-sonnet-5.5` drop to $0.10.
+- The end-to-end tests also run `claude-haiku-5-5`.
+- `llmsdk_docs/claude5_5/` adds the Haiku 5.5 pages and Anthropic's pricing page. The site and the skills list the new model.

changelog/unreleased/2026-10-09-claude-haiku-5-5.zh.md

@@ -0,0 +1,18 @@
+# 支持 Claude Haiku 5.5
+
+- **Date:** 2026-10-09
+- **Type:** feature
+- **Scope:** `anthropic_official`, `registry`
+- **PR:** [#249](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/249)
+
+[English](2026-10-09-claude-haiku-5-5.md)
+
+## 变更内容
+
+- `anthropic-official` 支持 `claude-haiku-5-5`，在各平台按版本匹配，包括带 `anthropic.` 前缀的 Bedrock id：
+  - `thinking_level="none"` 发送 `low` 档位的自适应思考，与 Opus 5.5 和 Fable 5.1 相同；其余档位发送同名的思考档位。
+  - `tool_choice="required"` 和工具名列表抛出 `UnsupportedParameterError`，与 Opus 5.5 和 Sonnet 5.5 相同。
+  - `fast_mode` 抛出 `UnsupportedParameterError`。
+- `list_supported_models` 列出 `claude-haiku-5-5`，每百万 token 输入 0.10 美元、输出 0.50 美元，缓存读取 0.01 美元，这是提示不超过 100K token 时的价格（超过后每项价格均为 5 倍）；OpenRouter 上的 `anthropic/claude-haiku-5.5` 价格相同。`claude-sonnet-5-5` 和 `anthropic/claude-sonnet-5.5` 的缓存读取降到 0.10 美元。
+- 端到端测试新增 `claude-haiku-5-5`。
+- `llmsdk_docs/claude5_5/` 新增 Haiku 5.5 的页面和 Anthropic 的价格页面。站点和 skill 列出了新模型。

changelog/unreleased/README.md

@@ -2,5 +2,6 @@
 
 [中文版](README.zh.md)
 
+- [2026-10-09] Support Claude Haiku 5.5: `anthropic-official` serves `claude-haiku-5-5` and `list_supported_models` lists it with OpenRouter's `anthropic/claude-haiku-5.5`; cache reads on Claude Sonnet 5.5 drop to $0.10. ([details](2026-10-09-claude-haiku-5-5.md), [#249](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/249))
 - [2026-10-09] The official Gemini client is `google-official` (alias `gemini-official`), named after its vendor like the other official clients; its class is `GoogleOfficialClient`. ([details](2026-10-09-google-official.md), [#248](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/248))
 - [2026-10-02] An MMSP server serves the models of a table over HTTP as MMSP streams (`python -m mmsp.integration.server --config FILE`, `npm run server -- --config FILE`); the playground's `/server/` page saves a table to a config file, starts one from it and draws its metrics over the last 60 days, and the `mmsp` client calls it; an error the server reports comes back as the new `UpstreamError`. ([details](2026-10-02-mmsp-server.md), [#247](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/247))

changelog/unreleased/README.zh.md

@@ -2,5 +2,6 @@
 
 [English](README.md)
 
+- [2026-10-09] 支持 Claude Haiku 5.5：`anthropic-official` 支持 `claude-haiku-5-5`，`list_supported_models` 列出它和 OpenRouter 上的 `anthropic/claude-haiku-5.5`；Claude Sonnet 5.5 的缓存读取降到 0.10 美元。([详情](2026-10-09-claude-haiku-5-5.zh.md), [#249](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/249))
 - [2026-10-09] Gemini 官方客户端改名为 `google-official`（别名 `gemini-official`），与其他官方客户端一样以厂商命名；类名改为 `GoogleOfficialClient`。([详情](2026-10-09-google-official.zh.md), [#248](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/248))
 - [2026-10-02] 新增 MMSP 服务端，通过 HTTP 把一张表里的模型提供为 MMSP 流（`python -m mmsp.integration.server --config FILE`、`npm run server -- --config FILE`）；Playground 的 `/server/` 页面把表保存到配置文件，据此启动服务端并画出其最近 60 天的指标；新增调用它的 `mmsp` 客户端；服务端报告的错误以新增的 `UpstreamError` 抛出。([详情](2026-10-02-mmsp-server.zh.md), [#247](https://github.com/Prism-Shadow/model-message-stream-protocol/pull/247))

llmsdk_docs/README.md

@@ -8,7 +8,7 @@ To use a specific model, please refer to its dedicated README:
 
 - **[Anthropic Messages protocol](./ant_messages/README.md)** - The Anthropic Messages-compatible protocol across Anthropic, OpenRouter, DeepSeek, Z.AI, and MiniMax (generic `ant_messages` client)
 - **[Claude 5.1](./claude5_1/README.md)** - Anthropic's Claude Fable 5.1: always-on thinking, no forced tool choice, history-bound thinking blocks
-- **[Claude 5.5](./claude5_5/README.md)** - Anthropic's Claude Opus 5.5 and Sonnet 5.5: always-on thinking on Opus, `between_tools` on Sonnet, no forced tool choice
+- **[Claude 5.5](./claude5_5/README.md)** - Anthropic's Claude Opus 5.5, Sonnet 5.5 and Haiku 5.5: always-on thinking on Opus, `between_tools` on Sonnet, adaptive thinking and long context pricing on Haiku
 - **[Claude 4.6](./claude4_6/README.md)** - Anthropic's Claude 4.6 API documentation and examples
 - **[Claude 4.7](./claude4_7/README.md)** - Anthropic's Claude 4.7 API documentation and examples
 - **[Claude 4.8](./claude4_8/README.md)** - Anthropic's Claude 4.8 API documentation and examples

llmsdk_docs/claude5_5/README.md

@@ -1,11 +1,15 @@
 # Claude 5.5 SDK Documentation
 
-Snapshot of Anthropic's documentation for Claude Opus 5.5 (`claude-opus-5-5`) and Claude Sonnet 5.5 (`claude-sonnet-5-5`), retrieved 2026-09-30 from platform.claude.com.
+Snapshot of Anthropic's documentation for Claude Opus 5.5 (`claude-opus-5-5`), Claude Sonnet 5.5 (`claude-sonnet-5-5`) and Claude Haiku 5.5 (`claude-haiku-5-5`), retrieved 2026-10-09 from platform.claude.com.
 
 ## Documentation
 
 - [models-overview.md](./docs/models-overview.md) - The current lineup: ids per platform, pricing, thinking modes, default effort
+- [pricing.md](./docs/pricing.md) - Model pricing, including Haiku 5.5's long context pricing (prompts over 100,000 tokens pay higher prices)
 - [overview-opus-5-5.md](./docs/overview-opus-5-5.md) - Claude Opus 5.5 model page
 - [migration-guide-opus-5-5.md](./docs/migration-guide-opus-5-5.md) - Migrating to Opus 5.5: thinking always on, `medium` default effort, forced `tool_choice` returns 400, no sampling parameters, thinking text omitted by default
 - [overview-sonnet-5-5.md](./docs/overview-sonnet-5-5.md) - Claude Sonnet 5.5 model page
-- [migration-guide-sonnet-5-5.md](./docs/migration-guide-sonnet-5-5.md) - Migrating to Sonnet 5.5: `thinking: {type: "between_tools"}` replaces `disabled` and is accepted only at `high` effort or below, forced `tool_choice` returns 400
+- [migration-guide-sonnet-5-5.md](./docs/migration-guide-sonnet-5-5.md) - Migrating to Sonnet 5.5: `thinking: {type: "between_tools"}` replaces `disabled` and is accepted only at `high` effort or below, forced `tool_choice` returns 400, cache reads at $0.10 / MTok
+- [overview-haiku-5-5.md](./docs/overview-haiku-5-5.md) - Claude Haiku 5.5 model page
+- [whats-new-haiku-5-5.md](./docs/whats-new-haiku-5-5.md) - What changed from Haiku 4.5: adaptive thinking on by default, `disabled` accepted at `high` effort or below, 1M context, 128K output
+- [migration-guide-haiku-5-5.md](./docs/migration-guide-haiku-5-5.md) - Migrating to Haiku 5.5: `budget_tokens` returns 400, sampling parameters restricted, no prefill, forced `tool_choice` accepted without thinking