vibeeval 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