fix: add missing API request headers for parity with Claude Code#109
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griffinmartin merged 2 commits intomainfrom Mar 31, 2026
Merged
fix: add missing API request headers for parity with Claude Code#109griffinmartin merged 2 commits intomainfrom
griffinmartin merged 2 commits intomainfrom
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Add headers that Claude Code sends on every API request: - anthropic-version: 2023-06-01 - x-client-request-id: unique UUID per request - X-Claude-Code-Session-Id: stable UUID per process lifetime Also fixes user-agent format from 'claude-cli/<v> (external, cli)' to 'claude-code/<v>' and bumps ccVersion to 2.1.88. Adds validate-oauth and validate-oauth-dry Makefile targets.
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@minzique thoughts? |
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I will take a look later today and let you know https://minzique.github.io/claude-code-re/ should have all the request formats auto documented going forward but i need to double check it, the pipeline's only been running for a couple weeks |
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@minzique Thanks for the resource. An hour after I opened this and went through the effort to decompile the bun binary the cc source code leaked 🤣 |
Claude Code's API User-Agent is 'claude-cli/<v> (external, cli)', not 'claude-code/<v>'. The latter is used for non-SDK HTTP requests only (transports, telemetry). Revert to the correct format.
griffinmartin
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Apr 3, 2026
## Summary Fixes #119 — API 400 for `claude-haiku-4-5-20251001`. - Adds a `haiku` model override in `model-config.ts` to exclude the `interleaved-thinking-2025-05-14` beta flag from haiku requests - Haiku 4.5 has limited extended thinking support (no adaptive thinking) and does not benefit from this beta — excluding it reduces the surface for API validation errors ## Root cause analysis The reported 400 error on plugin v1.3.0 was primarily caused by: 1. **Malformed billing header** — v1.3.0 used `cch=00000` (hardcoded) with the model ID embedded in the version string (`cc_version=2.1.80.claude-haiku-4-5-20251001`), which doesn't match the expected `cc_version=X.Y.Z.{3-char-hash}` format. Fixed in v1.4.3 (#116). 2. **Missing API headers** — `anthropic-version`, `x-client-request-id`, and `X-Claude-Code-Session-Id` were absent. Fixed in v1.4.2 (#109). This PR adds a defensive fix on top: excluding the `interleaved-thinking-2025-05-14` beta for haiku, since Claude Code CLI historically sent fewer betas to haiku (ref: `claude-code` v2.1.78 changelog) and the interleaved-thinking-with-tools behavior is not well-documented for haiku models. ## Changes - `src/model-config.ts` — Add `haiku` entry to `modelOverrides` excluding `interleaved-thinking-2025-05-14` - `src/betas.test.ts` — Update haiku test to verify excluded betas are rejected; add dedicated test for both `claude-haiku-4-5` and `claude-haiku-4-5-20251001` ## Test results ``` 191 tests, 0 failures lint: clean ```
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Summary
Adds missing HTTP headers to API requests to match what Claude Code sends, and bumps the version identifier to 2.1.88.
Changes
Headers added to
buildRequestHeaders(src/index.ts)anthropic-version: 2023-06-01— API version headerx-client-request-id— unique UUID per request for tracingX-Claude-Code-Session-Id— stable UUID per process lifetime (generated once viacrypto.randomUUID()at module load, never persisted to disk)User-Agent
claude-cli/<v> (external, cli)to match Claude Code's primary API User-Agent (src/utils/http.ts:getUserAgent()). Note:claude-code/<v>is used upstream only for non-SDK HTTP requests (transports, telemetry), not for API calls.Other fixes
ccVersionbumped from2.1.80to2.1.88validate-oauthandvalidate-oauth-dryMakefile targetsTests (
src/index.test.ts)x-client-request-idis unique per callX-Claude-Code-Session-Idis stable across callsAll 161 tests pass. Lint and build clean.