edit.md

Edit files using find-and-replace. Must read file first with view.

<when_to_use> Use Edit when:

  • Making targeted changes to existing code
  • Changing specific functions, lines, or blocks
  • Single file, 1-3 changes

Do NOT use Edit when:

  • Creating new files → use write
  • Complete file rewrite → use write
  • Multiple changes to same file → use multiedit
  • Moving/renaming files → use bash with mv </when_to_use>

<critical_rule> ALWAYS view the file first. The old_string must match EXACTLY—every space, tab, newline, and blank line. </critical_rule>

- file_path: Absolute path (required) - old_string: Exact text to find (required for edits, empty for new file) - new_string: Replacement text (required) - replace_all: Replace all occurrences (default: false)

<special_cases>

  • Create file: provide file_path + new_string, leave old_string empty
  • Delete content: provide file_path + old_string, leave new_string empty </special_cases>

<matching_rules> Include 3-5 lines of context to ensure unique match:

Good: Match entire function signature + first lines
old_string: "func ProcessUser(id string) error {\n    if id == \"\" {\n        return errors.New(\"empty\")\n    }"

Bad: Match just one line that appears many times
old_string: "return nil"

Tip: In large files, include the function or class signature as context to disambiguate similar code blocks. </matching_rules>

<common_failures>

Expected: "    func foo() {"     (4 spaces)
Provided: "  func foo() {"       (2 spaces) ❌

Expected: "}\n\nfunc bar()"      (blank line between)
Provided: "}\nfunc bar()"        (no blank line) ❌

Expected: "// comment"           (space after //)
Provided: "//comment"            ❌

</common_failures>

If "old_string not found": 1. `view` the file at target location 2. Copy exact text character-by-character 3. Include more surrounding context 4. Check tabs vs spaces, blank lines