feat(anthropic_official): support Claude Haiku 5.5

[hiyouga]

Summary

Support Claude Haiku 5.5 (claude-haiku-5-5, released 2026-10-07) and refresh the Claude 5.5 docs snapshot. Opus 5.5 and Sonnet 5.5 were already supported. Their official pages changed only in the lineup table and in Sonnet 5.5's cache-read price.

• anthropic-official serves claude-haiku-5-5, matched by the explicit haiku-5-5 version substring. That also covers Bedrock's anthropic.claude-haiku-5-5.
  • thinking_level="none" → adaptive thinking at low effort, as on Opus 5.5 / Fable 5.1. The other levels send the effort of the same name.
  • tool_choice="required" or a tool-name list → UnsupportedParameterError, as on Opus 5.5 / Sonnet 5.5.
  • fast_mode → UnsupportedParameterError.
  • The _ALWAYS_THINKING tuple is renamed _LOW_EFFORT_FOR_NONE (TS LOW_EFFORT_FOR_NONE), because Haiku 5.5 is not always-thinking.
• Registry
  • New claude-haiku-5-5 row: $0.10 / $0.50, cache reads $0.01, 1M context. This is the ≤100K-prompt tier; a comment notes that every rate is 5× above 100K, the same convention as MiniMax-M3 and gpt-6.1-sol.
  • New OpenRouter anthropic/claude-haiku-5.5 row, with prices from the live /models API.
  • Sonnet 5.5 cache reads drop $0.20 → $0.10 in both the official and OpenRouter rows, per the official pricing page and OpenRouter's API.
• Tests: a claude-haiku-5-5 entry in AVAILABLE_MODELS, and rows in the existing thinking-level and summary mapping tables.
• Docs
  • llmsdk_docs/claude5_5/ adds the Haiku 5.5 overview, migration guide and what's-new pages, plus the pricing page. The models overview, the Opus and Sonnet 5.5 pages and their migration guides are refreshed.
  • The site and skills list the new model.
• Changelog: changelog/unreleased/2026-10-09-claude-haiku-5-5.md (+ .zh.md).

Live probes (claude-haiku-5-5, raw HTTP, 2026-10-09)

Request	Result
no thinking config	200; adaptive thinking runs by default (it thinks at max even when no display is asked for)
thinking: disabled, effort default / low / high	200, no thinking
thinking: disabled, effort xhigh / max	400 "effort 'xhigh' is not supported when thinking is disabled on this model"
thinking: disabled + display	400 "Extra inputs are not permitted"
between_tools	400 "not supported for this model"
enabled + budget_tokens	400
adaptive, effort low … max	200
speed: "fast" (+ beta)	400 "does not support the speed parameter"
temperature: 1 / 0.5	200 / 400 "temperature is deprecated for this model" (the client already rejects ≠ 1 for all Claude)
tool_choice any / named tool	200, but the response has no thinking block
top-level cache_control 5m / 1h	200

Replay of a thinking-bearing assistant turn, both before tool results and in a later follow-up:

• Missing signature → 400 "Field required".
• Tampered signature → 400 "Invalid signature".
• Empty or edited thinking text → 200, with the input token count unchanged, so the signature carries the thinking.
• Dropping the thinking block → 200, but the thinking is lost.
• Dropping the tool_use caller field → 200.

The existing replay (thinking text + signature) is therefore kept unchanged. Usage now also carries output_tokens_details.thinking_tokens; the client keeps reading output_tokens as before.

Decisions (confirmed with the owner)

• NONE: Haiku 5.5 does accept disabled, but NONE maps to adaptive + low, consistent with Opus 5.5 / Fable 5.1. The alternatives were disabled and omitting the config (which leaves adaptive thinking at the default effort).
• Forced tool_choice: the API accepts it but silently skips thinking. It is rejected for consistency with the rest of the 5.5 family.
• Tiered pricing: the registry has a single price per bucket, so it stores the ≤100K tier and notes the 5× factor in a comment.

Test plan (vps4)

• Python unit: 635 passed, 15 skipped. ruff check and ruff format --check are clean.
• TS unit: 623 passed. eslint, tsc --noEmit, prettier and build are clean.
• Python e2e -k claude-haiku-5-5: 12 passed, 3 skipped (image generation / TTS / embedding are off by capability flags).
• TS e2e -t claude-haiku-5-5: 15 passed.

🤖 Generated with Claude Code

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