Morph Fast Apply
Fast, AI-powered file editing using the Morph Apply API. Edit files without reading them first. Processes at 10,500 tokens/sec with 98% accuracy.
When to Use Fast file edits without reading entire file first Batch edits to a file (multiple changes in one operation) When you know what to change but file is large Large files where reading would consume too many tokens Key Pattern: Code Markers
Use // ... existing code ... (or language-appropriate comments) to mark where edits go:
... existing code ...
try: result = process() except Exception as e: log.error(e)
... existing code ...
The API intelligently places your edit in the right location.
Usage Add error handling uv run python -m runtime.harness scripts/mcp/morph_apply.py \ --file "src/auth.py" \ --instruction "Add error handling to login function" \ --code_edit "# ... existing code ... try: user = authenticate(credentials) except AuthError as e: log.error(f'Auth failed: {e}') raise
... existing code ..."
Add logging uv run python -m runtime.harness scripts/mcp/morph_apply.py \ --file "src/api.py" \ --instruction "Add debug logging" \ --code_edit "# ... existing code ... logger.debug(f'Processing request: {request.id}')
... existing code ..."
TypeScript example uv run python -m runtime.harness scripts/mcp/morph_apply.py \ --file "src/types.ts" \ --instruction "Add user validation" \ --code_edit "// ... existing code ... if (!user) throw new Error('User not found'); if (!user.isActive) throw new Error('User inactive'); // ... existing code ..."
Parameters Parameter Description --file File path to edit (required) --instruction Human description of the change (required) --code_edit Code snippet with markers showing where to place edit (required) vs Claude's Edit Tool Tool Best For morph-apply Fast edits, don't need to read file first, large files, batch edits Claude Edit Small precise edits when file is already in context
Use morph-apply when:
File is not in context and reading it would be expensive File is very large (>500 lines) Making multiple related edits at once You know the context of the change (function name, class, etc.)
Use Claude Edit when:
File is already in context from prior Read Very precise edits requiring exact old/new string matching Small files (<200 lines) MCP Server Required
Requires morph server in mcp_config.json with MORPH_API_KEY.
Performance Speed: 10,500 tokens/sec Accuracy: 98% correct placement Token savings: Don't need to read entire file first