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2626* **Streaming patterns:** Implementation details for building chat UIs and handling incremental display
2727* **Batch processing:** Offline batch processing at 50% cost
2828* **Prompt caching:** Prefix-stability design, breakpoint placement, and silent-invalidator audit
29* **Model migration:** Step-by-step guidance for migrating to newer Claude models (including the breaking changes and behavior shifts on [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/migration-guide#migrating-from-claude-opus-4-8-to-claude-opus-5) and [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/migration-guide))
29* **Model migration:** Step-by-step guidance for migrating to newer Claude models (including the breaking changes and behavior shifts on [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5) and [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/migration-guide))
3030* **Current model information:** Model IDs, context window sizes, and pricing
3131* **Common pitfalls:** Detailed guidance on avoiding frequent mistakes when integrating with the API
3232
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102102The Claude API skill can perform Claude model migrations across a code base. Invoke it directly with `/claude-api migrate`:
103103
104104```text wrap
105/claude-api migrate this project to claude-opus-5
105/claude-api migrate this project to claude-opus-5-5
106106```
107107
108108You can also pass a specific scope up front to skip the scope-confirmation question:
109109
110110```text wrap
111/claude-api migrate everything under src/ to claude-opus-5
112/claude-api migrate apps/api.py and apps/worker.py to claude-opus-5
111/claude-api migrate everything under src/ to claude-opus-5-5
112/claude-api migrate apps/api.py and apps/worker.py to claude-opus-5-5
113113```
114114
115115When the scope is ambiguous (for example, a bare `/claude-api migrate to claude-opus-5`), the skill asks you to choose between the entire working directory, a specific subdirectory, or an explicit file list before editing any files. This applies to both Messages API and Managed Agents callers.
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124124* **Effort calibration**, recommending an `output_config.effort` starting point for the target model (for example, the default `high` on Claude Opus 5, and `xhigh` for coding and agentic use cases on Claude Opus 4.8 and Claude Opus 4.7)
125125* **Prompt-behavior tuning**, flagging length-control, tool-triggering, subagent, and instruction-following prompts that may behave differently on the target model
126126* **Silent default handling**, opting back into thinking summarization (`thinking.display: "summarized"`) when reasoning is surfaced to users on Claude Opus 4.8 and Claude Opus 4.7
127* **Refusal fallback configuration**, adding `stop_reason: "refusal"` handling before reading response content and setting up a [fallback retry path](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback) when the target is Claude Fable 5.1, Claude Fable 5, or Claude Opus 5 (the server-side `fallbacks` parameter, typically in its `"default"` mode, the SDK refusal-fallback middleware, or a fallback-credit retry), and updating fallback code written against earlier preview shapes
127* **Refusal fallback configuration**, adding `stop_reason: "refusal"` handling before reading response content and setting up a [fallback retry path](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback) when the target is Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, or Claude Opus 5 (the server-side `fallbacks` parameter, typically in its `"default"` mode, the SDK refusal-fallback middleware, or a fallback-credit retry), and updating fallback code written against earlier preview shapes
128128
129129As it edits, the skill explains each change and its motivation inline. On completion, it produces a checklist of items that require manual verification (typically integration tests, length-control prompt tuning, and cost/rate-limit re-baselining).
130130
131For the full list of model-specific changes the skill applies, see [Migrating to Claude Opus 5 from Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-5/migration-guide#migrating-from-claude-opus-4-8-to-claude-opus-5) and [Migrating to Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/migration-guide).
131For the full list of model-specific changes the skill applies, see [Migrating to Claude Opus 5.5 from Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5), [Migrating to Claude Opus 5 from Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-5/migration-guide#migrating-from-claude-opus-4-8-to-claude-opus-5), and [Migrating to Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/migration-guide).
132132
133133## Setting up a Managed Agent
134134
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155155**Migrating an existing project:**
156156
157157```text wrap
158/claude-api migrate this codebase to claude-opus-5 and re-tune effort
158/claude-api migrate this codebase to claude-opus-5-5 and re-tune effort
159159```
160160
161161**Onboarding a new Managed Agent:**