[BUG] Claude Code OAuth API fails when a tool is named read_file (works when renamed)

[loject]

Problem (one or two sentences)

Claude Code OAuth API request fails when the tools list contains a tool named read_file. Renaming the tool to _read_file makes the exact same request succeed.

Context (who is affected and when)

Affects users who are signed in with Claude Code OAuth. It happens when Roo Code sends any request that includes file-reading tools.

Reproduction steps

1. OS: Linux (any), Roo Code: current main, Provider: Claude Code OAuth, Model: claude-sonnet-4-5
2. Sign in with Claude Code OAuth.
3. Trigger any chat request where Roo Code sends tools including a tool named read_file (e.g. read a file from workspace).
4. Observe: the Claude Code API request fails.
5. Rename the tool from read_file to _read_file (no other changes).
6. Repeat the same request.
7. Observe: the request succeeds and tool calls still work.

Expected result

The request should succeed and the model should be able to call tools normally.

Actual result

The Claude Code OAuth API request fails only when a tool is named read_file. Renaming it to _read_file makes the same request succeed.

Variations tried (optional)

No response

App Version

3.41.3 and nightly 0.0.7779

API Provider (optional)

None

Model Used (optional)

Claude 4.5 Sonnet

Roo Code Task Links (optional)

No response

Relevant logs or errors (optional)

Date/time: 2026-01-21T15:39:34.349Z
Extension version: 0.0.7779
Provider: claude-code
Model: claude-sonnet-4-5

This credential is only authorized for use with Claude Code and cannot be used for other API requests.

[roomote]

I've analyzed this issue and here's my proposed implementation plan:

Problem Summary

Claude Code OAuth API has reserved tool names that conflict with Roo Code's native tools. Specifically, read_file is reserved by Claude Code's own tool system, causing API requests to fail with: "This credential is only authorized for use with Claude Code and cannot be used for other API requests."

Root Cause

When tools are sent to the Claude Code API in src/api/providers/claude-code.ts, the tool names are passed directly without any transformation. Claude Code's API rejects requests containing tools with reserved names.

Proposed Solution

Following the established pattern used for MCP tool name handling (in src/utils/mcp-name.ts), I'll implement a tool name transformation system for Claude Code:

1. Create src/utils/claude-code-tool-name.ts

• Define a set of reserved tool names: read_file (and potentially others if discovered)
• Define a prefix: CLAUDE_CODE_TOOL_PREFIX = "roo_"
• Add functions:
  • prefixClaudeCodeToolName(name) - adds prefix to reserved names (e.g., read_file → roo_read_file)
  • unprefixClaudeCodeToolName(name) - removes prefix from prefixed names

2. Modify src/api/providers/claude-code.ts

• Transform tool names when converting tools for the API request
• Un-prefix tool names in tool_call_partial chunks received from the API

3. Modify src/integrations/claude-code/streaming-client.ts

• Transform tool_use block names in conversation history messages before sending
• This ensures that previous tool_use blocks in the conversation are also properly prefixed

4. Add comprehensive tests

• Unit tests for the new utility functions
• Update existing Claude Code handler tests

Benefits

• Transparent to the rest of the codebase - only Claude Code provider needs changes
• Follows established patterns (similar to MCP tool name handling)
• Minimal code changes with focused scope
• Easy to extend if more reserved names are discovered

Please mention @roomote in a comment saying that you approve this plan, and I'll proceed with the implementation.