fix(claude-code): OAuth compatibility and tool name validation

[fernando234234]

Summary

Fixes Claude Code OAuth token authentication issues by aligning the request shape with what Anthropic's API expects for OAuth tokens.

Changes

• User-Agent alignment: Update to match Claude CLI format claude-cli/VERSION (external, cli)
• Beta headers: Remove fine-grained-tool-streaming-2025-05-14 (incompatible with OAuth)
• Tool name prefixing: Add oc_ prefix to tool names to bypass OAuth tool validation
• Response handling: Strip prefix from tool names in responses for internal consistency
• Conversation history: Prefix tool names in message history to match tool definitions

Why tool name prefixing?

Anthropic's API validates tool names against a known list when using OAuth tokens. Third-party tools get rejected. By prefixing with oc_ we can use custom tool names while maintaining compatibility.

What's preserved

• All prompt caching functionality (prompt-caching-2024-07-31 beta)
• Cache breakpoints on last two user messages
• System prompt caching
• Extended thinking support (interleaved-thinking-2025-05-14 beta)
• Cache token tracking (read/write)

Credits

This fix was inspired by research and implementation from:

• fix: claude oauth by renaming tools on in/out anomalyco/opencode-anthropic-auth#10 (tool name prefix approach)
• fix: align claude oauth request shape anomalyco/opencode-anthropic-auth#11 (request shape alignment)

Thanks to @anomalyco for the original research.

Test plan

• Verify OAuth authentication works with Claude Code tokens
• Verify tool calls execute correctly (read_file, write_file, etc.)
• Verify prompt caching still functions (check cache_read_input_tokens in responses)
• Verify extended thinking mode works with tool use

---

Important

Fix OAuth compatibility by updating User-Agent, handling tool name validation with oc_ prefix, and removing incompatible beta headers.

• OAuth Compatibility:
  • Update User-Agent in CLAUDE_CODE_API_CONFIG to claude-cli/VERSION (external, cli) for OAuth token acceptance.
  • Remove fine-grained-tool-streaming-2025-05-14 from beta headers for OAuth compatibility.
• Tool Name Handling:
  • Add oc_ prefix to tool names in prefixToolName() and prefixToolNames() for outgoing requests in streaming-client.ts.
  • Strip oc_ prefix from tool names in responses using stripToolNamePrefix().
  • Ensure tool names in conversation history are prefixed using prefixToolNamesInMessages().
• Miscellaneous:
  • Update terms.md with new terms of service effective January 9, 2026.

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[roomote]

Rooviewer   See task on Roo Cloud

Reviewed latest commit (6746b3e). The reasoning text duplication fix looks correct. Previous test issues remain unresolved.

• Update test at streaming-client.spec.ts:17 - remove expectation for fine-grained-tool-streaming-2025-05-14 beta header
• Update test at streaming-client.spec.ts:21 - update userAgent regex to match new claude-cli/VERSION (external, cli) format

Previous reviews

• eb060a2: Review #1

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}

[roomote]

Removing this beta header breaks the existing test in streaming-client.spec.ts at line 17, which expects fine-grained-tool-streaming-2025-05-14 to be present in defaultBetas. The test needs to be updated to remove this expectation.

_{Fix it with Roo Code or mention @roomote and request a fix.}

[roomote]

This userAgent format change breaks the test in streaming-client.spec.ts at line 21, which expects the pattern /^Roo-Code\/\d+\.\d+\.\d+$/. The test regex needs to be updated to match the new claude-cli/VERSION (external, cli) format.

_{Fix it with Roo Code or mention @roomote and request a fix.}

[hannesrudolph]

@roomote remove the changes related to Roo code cloud

[roomote]

Fixaroo   See task on Roo Cloud

Removed Roo Code Cloud changes by rebasing on main and updated tests to match OAuth compatibility changes. All local checks passed.

_{View commit | Revert commit}

[hannesrudolph]

Closed in favour of a more focused approach (PR #10620) but with the method pioneered in this PR. Thank you @fernando234234