[docs] Document Anthropic deprecated beta header retry handling

[github-actions]

Documentation Sync - Anthropic Beta Header Retry Handling

This PR synchronizes documentation with code changes from commit 881da1d by documenting the automatic retry behavior for deprecated Anthropic anthropic-beta header values.

Changes Made

• docs/api-proxy-sidecar.md: Added section documenting automatic retry and correction for deprecated anthropic-beta header values
  • Explains that the proxy detects and automatically retries requests when Anthropic rejects deprecated beta values
  • Documents the "learning" behavior where deprecated values are proactively stripped from subsequent requests
  • Clarifies that this behavior is transparent to clients and requires no code changes

Code Changes Referenced

• 881da1d - "Retry Anthropic requests after deprecated anthropic-beta header rejection (Retry Anthropic requests after deprecated anthropic-beta header rejection #3657)"
  • Implements automatic detection of deprecated Anthropic API beta values
  • Adds retry logic that removes deprecated values and re-sends requests
  • Tracks deprecated values to proactively strip them from future requests

Verification

• Code review: Verified the retry logic in containers/api-proxy/proxy-request.js
• Documentation consistency: Updated API proxy sidecar docs to match implementation
• Examples: Added clear example of how the retry behavior works with multiple beta values
• Style: Documentation uses consistent format with existing sections

This is a documentation-only change that improves clarity for users relying on the Anthropic API proxy without changing any behavior or logic.

Generated by Documentation Maintainer · ● 66.4K · ◷

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Documentation Preview

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Built from commit eefde10

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Smoke Test Results

PR #3667 — [docs] Document Anthropic deprecated beta header retry handling

• ✅ GitHub MCP connectivity (verified PR Retry Anthropic requests after deprecated anthropic-beta header rejection #3657)
• ❓ GitHub.com HTTP test (pre-step data unavailable)
• ❌ File write/read test (file not found)

Overall Status: FAIL ⚠️

cc @github-actions[bot]

📰 BREAKING: Report filed by Smoke Copilot

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Smoke Test Results ✅

All validation checks passed:

• ✅ GitHub API: 2 recent PR entries confirmed
• ✅ GitHub check: playwright_check PASS
• ✅ File verify: smoke-test-claude-26353446492.txt exists

Status: PASS — Claude engine validation complete.

💥 [THE END] — Illustrated by Smoke Claude

[github-actions]

Smoke Test: Copilot BYOK (Offline Mode) ✅

• ✅ GitHub MCP: Retrieved PR Retry Anthropic requests after deprecated anthropic-beta header rejection #3657 (Retry Anthropic requests after deprecated anthropic-beta header rejection)
• ❌ File test: /tmp/gh-aw/agent/smoke-test.txt not found
• ✅ BYOK inference: Running in offline mode (COPILOT_OFFLINE=true) via api-proxy → api.githubcopilot.com

Status: PARTIAL PASS (1 file test failed, core BYOK functionality working)

@github-actions[bot]

🔑 BYOK report filed by Smoke Copilot BYOK

[github-actions]

✅ GitHub MCP: Retry Anthropic requests after deprecated anthropic-beta header rejection; Refactor agent volume assembly into focused mount modules
❌ Safe Inputs GH CLI: safeinputs-gh unavailable; queried PRs with gh fallback
✅ Playwright: title contains GitHub
❌ Tavily: MCP server exposed no callable search tool
✅ File/Bash: smoke file created and read
✅ Discussion: oracle comment posted to #3676
✅ Build: npm ci && npm run build
Overall status: FAIL

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

• registry.npmjs.org

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "registry.npmjs.org"

See Network Configuration for more information.

🔮 The oracle has spoken through Smoke Codex

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Service Connectivity Results

❌ Redis: Connection timeout (no PONG response)
❌ PostgreSQL pg_isready: Connection timeout (no response)
❌ PostgreSQL SELECT: Not tested (pg_isready failed)

Overall: FAIL — Services on host.docker.internal are not reachable from AWF sandbox

🔌 Service connectivity validated by Smoke Services

[github-actions]

Gemini Smoke Test Results: FAIL (MCP/Connectivity failed, File/Bash passed)

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

• localhost

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "localhost"

See Network Configuration for more information.

💎 Faceted by Smoke Gemini

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🏗️ Build Test Suite Results

Ecosystem	Project	Build/Install	Tests	Status
Bun	elysia	✅	1/1 passed	✅ PASS
Bun	hono	✅	1/1 passed	✅ PASS
C++	fmt	✅	N/A	✅ PASS
C++	json	✅	N/A	✅ PASS
Deno	oak	N/A	1/1 passed	✅ PASS
Deno	std	N/A	1/1 passed	✅ PASS
.NET	hello-world	✅	N/A	✅ PASS
.NET	json-parse	✅	N/A	✅ PASS
Go	color	✅	all passed	✅ PASS
Go	env	✅	all passed	✅ PASS
Go	uuid	✅	all passed	✅ PASS
Java	gson	✅	1/1 passed	✅ PASS
Java	caffeine	✅	1/1 passed	✅ PASS
Node.js	clsx	✅	all passed	✅ PASS
Node.js	execa	✅	all passed	✅ PASS
Node.js	p-limit	✅	all passed	✅ PASS
Rust	fd	✅	1/1 passed	✅ PASS
Rust	zoxide	✅	1/1 passed	✅ PASS

Overall: 8/8 ecosystems passed — ✅ PASS

All build and test operations completed successfully across all supported language ecosystems.

Generated by Build Test Suite for issue #3667 · ● 16.6M · ◷