--- name: claude-opus-4-5-migration-ec3f9c16195a description: Migrate prompts and code from Claude Sonnet 4.0, Sonnet 4.5, or Opus 4.1 to Opus 4.5. Use when the user wants to update their codebase, prompts, or API calls to use Opus 4.5. Handles model string updates and prompt adjustments for known Opus 4.5 behavioral differences. Does NOT migrate Haiku 4.5. --- # Opus 4.5 Migration Guide One-shot migration from Sonnet 4.0, Sonnet 4.5, or Opus 4.1 to Opus 4.5. ## Migration Workflow 1. Search codebase for model strings and API calls 2. Update model strings to Opus 4.5 (see platform-specific strings below) 3. Remove unsupported beta headers 4. Add effort parameter set to `"high"` (see `references/effort.md`) 5. Summarize all changes made 6. Tell the user: "If you encounter any issues with Opus 4.5, let me know and I can help adjust your prompts." ## Model String Updates Identify which platform the codebase uses, then replace model strings accordingly. ### Unsupported Beta Headers Remove the `context-1m-2025-08-07` beta header if present—it is not yet supported with Opus 4.5. Leave a comment noting this: ```python # Note: 1M context beta (context-1m-2025-08-07) not yet supported with Opus 4.5 ``` ### Target Model Strings (Opus 4.5) | Platform | Opus 4.5 Model String | |----------|----------------------| | Anthropic API (1P) | `claude-opus-4-5-20251101` | | AWS Bedrock | `anthropic.claude-opus-4-5-20251101-v1:0` | | Google Vertex AI | `claude-opus-4-5@20251101` | | Azure AI Foundry | `claude-opus-4-5-20251101` | ### Source Model Strings to Replace | Source Model | Anthropic API (1P) | AWS Bedrock | Google Vertex AI | |--------------|-------------------|-------------|------------------| | Sonnet 4.0 | `claude-sonnet-4-20250514` | `anthropic.claude-sonnet-4-20250514-v1:0` | `claude-sonnet-4@20250514` | | Sonnet 4.5 | `claude-sonnet-4-5-20250929` | `anthropic.claude-sonnet-4-5-20250929-v1:0` | `claude-sonnet-4-5@20250929` | | Opus 4.1 | `claude-opus-4-1-20250422` | `anthropic.claude-opus-4-1-20250422-v1:0` | `claude-opus-4-1@20250422` | **Do NOT migrate**: Any Haiku models (e.g., `claude-haiku-4-5-20251001`). ## Prompt Adjustments Opus 4.5 has known behavioral differences from previous models. **Only apply these fixes if the user explicitly requests them or reports a specific issue.** By default, just update model strings. **Integration guidelines**: When adding snippets, don't just append them to prompts. Integrate them thoughtfully: - Use XML tags (e.g., ``, ``) to organize additions - Match the style and structure of the existing prompt - Place snippets in logical locations (e.g., coding guidelines near other coding instructions) - If the prompt already uses XML tags, add new content within appropriate existing tags or create consistent new ones ### 1. Tool Overtriggering Opus 4.5 is more responsive to system prompts. Aggressive language that prevented undertriggering on previous models may now cause overtriggering. **Apply if**: User reports tools being called too frequently or unnecessarily. **Find and soften**: - `CRITICAL:` → remove or soften - `You MUST...` → `You should...` - `ALWAYS do X` → `Do X` - `NEVER skip...` → `Don't skip...` - `REQUIRED` → remove or soften Only apply to tool-triggering instructions. Leave other uses of emphasis alone. ### 2. Over-Engineering Prevention Opus 4.5 tends to create extra files, add unnecessary abstractions, or build unrequested flexibility. **Apply if**: User reports unwanted files, excessive abstraction, or unrequested features. Add the snippet from `references/prompt-snippets.md`. ### 3. Code Exploration Opus 4.5 can be overly conservative about exploring code, proposing solutions without reading files. **Apply if**: User reports the model proposing fixes without inspecting relevant code. Add the snippet from `references/prompt-snippets.md`. ### 4. Frontend Design **Apply if**: User requests improved frontend design quality or reports generic-looking outputs. Add the frontend aesthetics snippet from `references/prompt-snippets.md`. ### 5. Thinking Sensitivity When extended thinking is not enabled (the default), Opus 4.5 is particularly sensitive to the word "think" and its variants. Extended thinking is enabled only if the API request contains a `thinking` parameter. **Apply if**: User reports issues related to "thinking" while extended thinking is not enabled (no `thinking` parameter in request). Replace "think" with alternatives like "consider," "believe," or "evaluate." ## Reference See `references/prompt-snippets.md` for the full text of each snippet to add. See `references/effort.md` for configuring the effort parameter (only if user requests it). --- Source attribution: Activer007 Original project: https://github.com/Activer007/ordinary-claude-skills/blob/e3e1b3d55f9a132a68d242040d23048a7ba8f85c/skills_all/claude-opus-4-5-migration/SKILL.md License: MIT License information: https://opensource.org/license/mit Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice MIT License Copyright (c) 2025 Microck Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. i did not write most of these. i just collected them. * **anthropic skills:** mit license (mostly) * **community skills:** check the `LICENSE` file in each specific folder. credits go to https://github.com/anthropics, https://github.com/obra, https://github.com/ComposioHQ, and the other people listed in the source tables. if you own one of these and want me to take it down, just open an issue and i will nuke it. # Mega AI Hub resource metadata Creator / publisher: Activer007 Original project: https://github.com/Activer007/ordinary-claude-skills/blob/e3e1b3d55f9a132a68d242040d23048a7ba8f85c/skills_all/claude-opus-4-5-migration/SKILL.md Attribution basis: Source repository record Fields of work: Development & Engineering, Product Management Roles: Backend Developer, ML / AI Engineer, Product Manager Specialties: API, Backend Tools: Anthropic Api, Aws Bedrock, Azure Ai Foundry, Google Vertex Ai Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 1bd2e4ee94365518c91824ccb81c50920cc7a59b98beb7325fb8fb23a6d1992a