openclaw - 💡(How to fix) Fix [Bug]: edit tool fails with "Expected ',' or ']'" error when edits array contains multi-line oldText/newText [1 participants]

Bug type

Crash (process/app exits or hangs)

Beta release blocker

No

Summary

edit Tool JSON Parameter Encoding Breaks with Multi-Line Text in Nested Arrays

Steps to reproduce

1. Call the edit tool with an edits array containing multi-line text:

{ "path": "path/to/file.md", "edits": [ { "oldText": "Line 1\nLine 2\nLine 3", "newText": "Replacement text with\nmultiple lines" } ] }

1. The tool call succeeds locally but fails with a JSON parse error when sent to Anthropic's API

Expected behavior

• The edit tool should successfully replace multi-line text blocks • Files with newlines, special characters, and Unicode should be editable

Actual behavior

• JSON parameter encoding breaks when the edits array contains multi-line strings • Error originates from Anthropic's JSON parser (not a tool execution error) • The error message is misleading — appears to be a file content issue, but is actually a parameter serialization issue

OpenClaw version

v24.14.0

Operating system

Windows 10

Install method

npm global

Model

claud-opus-4.6

Provider / routing chain

openclaw

Additional provider/model setup details

No response

Logs, screenshots, and evidence

Gateway error log shows: error=Expected ',' or ']' after array element in JSON at position 1164 (line 1 column 1165)

The raw_params logged show the edits array parameter is truncated/corrupted in the JSON before reaching the API.

Suggested Fix:

• Ensure proper JSON escaping (newlines as \n, quotes as \", etc.) when serializing nested edits array parameters
• Or: Use JSON.stringify with proper encoding for complex parameter types
• Test with multi-line text in nested array parameters before API calls

Impact and severity

Affected users/systems/channels:

• Any OpenClaw user attempting to use the edit tool with multi-line text in file modifications • Specifically: developers, documentarians, and agents working with markdown, code, or spec files

Severity: Blocks workflow. The edit tool becomes unusable for any real-world file editing task (most files have multi-line content). Users must abandon the tool and use workarounds (write + read cycle).

Frequency: Always — occurs consistently whenever multi-line oldText or newText is provided to the edits array. Not an edge case; it's the normal use case for file editing.

Consequence:

• Lost productivity: extra steps required (read → modify → write instead of direct edit) • Confusion: error message is misleading (appears to be file corruption, not parameter encoding) • 15+ hour diagnostic lag: errors visible in logs but not caught proactively (from lesson #130, happened 2026-04-23 14:14:54, not caught until 2026-04-24 05:55+) • Repeated mistakes: same issue recurred in this session because the underlying tool bug was never fixed

Evidence:

• Gateway logs: consistent JSON parse errors at Anthropic API boundary (position 1164, 1486, etc.) • Reproduction: every attempt to use edit with newlines fails; simple single-line edits succeed • Workaround effectiveness: switching to write tool resolves the issue immediately (confirmed working)

Additional information

Regression history:

• First observed: 2026-04-23 14:14:54 (gateway logs show "Bad Unicode escape in JSON at position 784") • Related to: Lesson #130 documented the same pattern occurring on files with emoji/special characters • Root cause then: PowerShell encoding layer mangling UTF-8 during edit operations • Root cause now: JSON parameter encoding breaking on nested array structures with multi-line text • Pattern: Same tool (edit), same class of error (JSON parse failures), different underlying cause

Related issues/lessons:

• Lesson #130: "JSON corruption errors from edit tool when writing emoji files" (2026-04-23) • This appears to be a broader issue with the edit tool's parameter serialization, not just emoji-related

Affected tool versions:

• Tool: edit (OpenClaw built-in) • Consistent behavior across multiple sessions (2026-04-23 and 2026-04-24) • No version number change observed between sessions, issue persists

Diagnostic evidence:

• Gateway logs show raw_params with truncated JSON in error messages • The truncation point correlates with position of multi-line oldText content • Simple parameter values (no newlines) serialize cleanly; complex nested arrays with newlines fail consistently

Workaround effectiveness:

• write tool (simple string parameters) works reliably • Node.js fs module (handles UTF-8 explicitly) works reliably • Issue is isolated to edit tool's parameter encoding, not to the underlying filesystem or OpenClaw runtime