Problem

After the chroot key helper fix (PR #1508), the script copy and config path updates work correctly, and the firewall allows traffic through to api.anthropic.com. However, all Anthropic API calls fail with error: "unknown", error_status: null, and zero tokens consumed — indicating the requests reach Anthropic but are rejected.

Observed behavior (from gh-aw#23614 comment)

[entrypoint] ✓ Updated apiKeyHelper path in /host/home/runner/.claude.json
[entrypoint] ✓ Updated apiKeyHelper path in /host/home/runner/.claude/settings.json
[entrypoint] Claude key helper copied to chroot at /tmp/awf-lib/get-claude-key.sh

• ✅ Chroot fix works (paths updated)
• ✅ Squid allows 4 requests to api.anthropic.com (0 blocked)
• ❌ All 10 API retries fail: error: "unknown", error_status: null
• ❌ Zero tokens consumed, zero cost — API never successfully authenticated

The ANTHROPIC_API_KEY works fine outside gh-aw (validated by the activation step).

Environment

• AWF: v0.25.4
• gh-aw: v0.64.5
• Claude Code CLI: 2.1.88
• Failed run: https://github.com/usepepper/salsa/actions/runs/23814978435

Authentication Chain Analysis

The expected chain:

Claude Code → apiKeyHelper (get-claude-key.sh)
  → returns "sk-ant-placeholder-key-for-credential-isolation"
  → sends x-api-key: <placeholder> to ANTHROPIC_BASE_URL (http://172.30.0.30:10001)
  → api-proxy strips x-api-key, injects real ANTHROPIC_API_KEY
  → forwards through Squid to api.anthropic.com
  → Anthropic authenticates with real key

The chain breaks somewhere between the api-proxy injecting the key and Anthropic accepting the request.

Hypotheses

H1: Claude Code 2.1.88 auth mechanism mismatch

Claude Code may use a different auth flow than the standard Anthropic SDK:

• Might send Authorization: Bearer instead of or in addition to x-api-key
• Might use a different API endpoint path (e.g., /v1/complete vs /v1/messages)
• Might require an anthropic-version header value newer than the proxy's default 2023-06-01

The api-proxy strips authorization and x-api-key headers and only injects x-api-key. If Claude Code requires a header the proxy doesn't inject, auth would fail.

H2: ANTHROPIC_AUTH_TOKEN interference

The agent has TWO different placeholder values:

• ANTHROPIC_AUTH_TOKEN=placeholder-token-for-credential-isolation (env var, docker-manager.ts:1450)
• apiKeyHelper returns sk-ant-placeholder-key-for-credential-isolation (script output)

Claude Code might prefer ANTHROPIC_AUTH_TOKEN over apiKeyHelper for certain operations, sending it as a different header that the proxy doesn't handle. Or the two conflicting values might cause confusion in Claude Code's auth logic.

H3: SSE streaming response not proxied correctly

The error_status: null (not 401/403) suggests Claude Code can't parse the response rather than receiving a clear auth error. The api-proxy uses proxyRequest() which pipes the upstream response back — if SSE chunked encoding is mangled, Claude Code would see "unknown" errors.

H4: Squid CONNECT tunnel issue

The 4 "allowed" Squid requests might be CONNECT tunnel establishments (HTTP 200), not the actual API calls. The real API responses within the tunnel might be failing. Squid logs showing TCP_TUNNEL:HIER_DIRECT with status 200 only means the tunnel was established, not that the API call succeeded.

Suggested Investigation

1. Enable api-proxy debug logging and check if requests are being received and forwarded with the correct x-api-key header
2. Compare headers sent by Claude Code 2.1.88 vs what the proxy expects — check if Claude Code sends auth in a header the proxy doesn't handle
3. Check the Anthropic response status in the api-proxy logs (before it's sent back to the agent)
4. Test with curl through the same proxy chain to isolate whether it's a Claude Code-specific issue:

   curl -v http://172.30.0.30:10001/v1/messages \
     -H "content-type: application/json" \
     -H "anthropic-version: 2023-06-01" \
     -d '{"model":"claude-sonnet-4-20250514","max_tokens":10,"messages":[{"role":"user","content":"hi"}]}'

5. Try removing ANTHROPIC_AUTH_TOKEN from the agent environment to see if it interferes with apiKeyHelper

References

• Upstream: engine: claude — get-claude-key.sh missing in chroot (AWF v0.25.4), apiKeyHelper exit 127 gh-aw#23614
• Chroot fix: fix: copy get-claude-key.sh to chroot-accessible path #1508
• Config path fix: fix: write apiKeyHelper to ~/.claude/settings.json for Claude Code v2.1.81+ #1414
• Api-proxy Anthropic handler: containers/api-proxy/server.js:718-749
• Key helper: containers/agent/get-claude-key.sh
• Agent env setup: src/docker-manager.ts:1438-1457
• Api-proxy env setup: src/docker-manager.ts:1358-1370