* Update claude-api skill: Claude Opus 5
- Add Claude Opus 5 (`claude-opus-5`) as the default model across all
SDK examples, model tables, pricing, and migration guidance.
- Add an Opus 5 migration section covering the API changes that come
with it, and move Opus 4.8 into the previous-generation slot.
- Drop the Opus 4.7 fast-mode guidance, which no longer applies.
- Scope the server-side fallbacks beta header to the current version.
* Update claude-api skill: Opus 5 fast-follow corrections
- Server-side refusal fallbacks are available on Claude Platform on AWS,
not just the Claude API. Correct the availability statements in
SKILL.md, the migration guide, and the platform-availability table.
- Simplify the effort guidance: start at `high` (the API default) and
sweep down, rather than starting at `xhigh` for coding work.
- Add a time-to-first-token section with the prompt instruction that
reduces pre-answer thinking on latency-sensitive routes.
- Replace the two separate thinking-disabled mitigations with the single
combined instruction that covers both failure modes.
- Add Claude Fable 5 and Claude Mythos 5 to the model tables with pricing,
context window, and model-selection guidance
- Document Fable-specific API behavior: always-on adaptive thinking (explicit
disabled returns 400), protected-thinking display and replay rules, new
tokenizer (~30% more tokens), refusal stop reason with server-side fallbacks
and SDK fallback middleware, 30-day data-retention requirement
- Add the full Migrating to Claude Fable 5 guide section and checklist,
including the Mythos Preview migration path
- Refresh skill trigger description, effort/compaction/task-budget notes,
caching minimums, structured-output and dynamic-filtering support tables
Documentation skill for building applications with the Claude API
and Agent SDK. Covers Python, TypeScript, Java, Go, Ruby, C#, PHP,
and cURL with language-specific guides for:
- Messages API basics, streaming, and error handling
- Tool use (tool runner and manual agentic loop)
- Structured outputs and adaptive thinking
- Batches and Files APIs
- Agent SDK patterns (Python/TypeScript)
- Model catalog and selection guidance
Lance Martin