## Description Codex's subscription usage window (primary/secondary rate-limit gauges) stopped populating for ChatGPT-OAuth sessions. This PR restores it by polling Codex's dedicated usage endpoint instead of relying on response headers that are no longer sent. ### Why the previous approach no longer works The existing code populates `CodexRateLimitState` from `x-codex-*` rate-limit headers captured on the `/v1/responses` WebSocket handshake (`update_from_headers` at WS accept). That worked when OpenAI returned `x-codex-primary-used-percent`, `x-codex-primary-window-minutes`, etc. on the handshake response. OpenAI has since stopped sending those headers on the ChatGPT WebSocket handshake. I confirmed this by faithfully replaying a real Plus-account handshake (both `prewarm` and regular `request_kind`): no `x-codex-*` headers come back on either. This matches OpenAI's own move to a dedicated usage endpoint (`GET /backend-api/codex/usage` in CodexApi mode) and reports such as openai/codex#14728. So `update_from_headers` now runs on every accept but finds nothing to parse, and the window silently stays empty. The headers aren't coming back, so there is nothing to fix in the parsing path. The data now lives behind a request we have to make ourselves. ## Type of Change - [x] Bug fix (non-breaking change that fixes an issue) ## Changes Made - `subscription/codex_rate_limits.py`: - `parse_codex_usage_payload()` / `update_from_usage_payload()` — map the `GET /backend-api/wham/usage` JSON (`rate_limit.primary_window` / `secondary_window` with `used_percent`, `limit_window_seconds`, `reset_at`; `credits`; `rate_limit_reached_type`) into the existing `CodexRateLimitState`. `limit_window_seconds` is converted to window-minutes with the same round-up codex-rs uses (`(secs + 59) // 60`). - `maybe_schedule_usage_poll()` — fire-and-forget, throttled to one request per 60s, scoped to ChatGPT sessions (requires both a Bearer token and `ChatGPT-Account-Id`; API-key traffic is skipped). Uses an in-flight guard so concurrent accepts don't stack polls. Endpoint is overridable via `HEADROOM_CODEX_USAGE_URL`. - `proxy/handlers/openai.py`: - At the Codex WS accept site, after the now-usually-empty `update_from_headers` block, schedule the usage poll. Wrapped in `contextlib.suppress` and fully non-blocking so it can never delay or fail the WebSocket accept. The old header-capture path is intentionally left in place as a no-cost fallback in case OpenAI restores the headers. ## Testing - [x] Unit tests pass (`pytest`) - [x] Linting passes (`ruff check .`) - [x] Type checking passes (`mypy headroom`) - [x] New tests added for new functionality - [x] Manual testing performed (live `/wham/usage` replay against a Plus account returned HTTP 200 with the expected schema; payload fixture in tests mirrors that real shape) ## Test Output ``` $ uv run pytest tests/test_codex_rate_limits.py -q ........................................ [100%] 41 passed in 0.16s $ uv run ruff check headroom/subscription/codex_rate_limits.py headroom/proxy/handlers/openai.py tests/test_codex_rate_limits.py All checks passed! $ uv run mypy headroom/subscription/codex_rate_limits.py Success: no issues found in 1 source file ``` ## Additional Notes - New tests cover: full-payload mapping, window-minutes round-up, credits balance kept only when `has_credits`, promo object vs string, empty payload returns `None`, missing `used_percent` skipped, header-gating (requires Bearer + account-id), poll throttling, and no-event-loop safety. - Scoping to `ChatGPT-Account-Id` keeps the poll off API-key traffic, and the 60s throttle plus in-flight guard bound it to at most one lightweight GET per minute per running proxy. --------- Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com> |
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|---|---|---|
| .claude-plugin | ||
| .devcontainer | ||
| .github | ||
| benchmarks | ||
| crates | ||
| docker | ||
| docs | ||
| e2e | ||
| examples | ||
| headroom | ||
| plugins | ||
| REALIGNMENT | ||
| scripts | ||
| sdk/typescript | ||
| sql | ||
| tests | ||
| wiki | ||
| .actrc | ||
| .actrc.local.example | ||
| .changelog.md | ||
| .commitlintrc.json | ||
| .dockerignore | ||
| .env.act.example | ||
| .env.example | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitguardian.yaml | ||
| .gitignore | ||
| .pre-commit-config.yaml | ||
| .release-please-config.json | ||
| .release-please-manifest.json | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| claude_analysis_ttl.py | ||
| CODE_OF_CONDUCT.md | ||
| codecov.yml | ||
| CONTRIBUTING.md | ||
| deny.toml | ||
| docker-bake.hcl | ||
| docker-compose.yml | ||
| Dockerfile | ||
| ENTERPRISE.md | ||
| Headroom-2.gif | ||
| headroom-savings.png | ||
| headroom_learn.gif | ||
| HeadroomDemo-Fast.gif | ||
| LICENSE | ||
| llms.txt | ||
| Makefile | ||
| mkdocs.yml | ||
| NOTICE | ||
| PR.md | ||
| pyproject.toml | ||
| README.md | ||
| rust-toolchain.toml | ||
| RUST_DEV.md | ||
| SECURITY.md | ||
| TESTING-copilot-subscription.md | ||
| uv.lock | ||
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The context compression layer for AI agents
60–95% fewer tokens · library · proxy · MCP · 6 algorithms · local-first · reversible
Docs · Install · Proof · Agents · Discord · llms.txt · Enterprise
AI agents / LLMs: read /llms.txt here, or fetch the live index / full docs blob.
Headroom compresses everything your AI agent reads — tool outputs, logs, RAG chunks, files, and conversation history — before it reaches the LLM. Same answers, fraction of the tokens.
Live: 10,144 → 1,260 tokens — same FATAL found.
What it does
- Library —
compress(messages)in Python or TypeScript, inline in any app - Proxy —
headroom proxy --port 8787, zero code changes, any language - Agent wrap —
headroom wrap claude|codex|cursor|aider|copilotin one command - MCP server —
headroom_compress,headroom_retrieve,headroom_statsfor any MCP client - Cross-agent memory — shared store across Claude, Codex, Gemini, auto-dedup
headroom learn— mines failed sessions, writes corrections toCLAUDE.md/AGENTS.md- Reversible (CCR) — originals are cached for retrieval on demand
How it works (30 seconds)
Your agent / app
(Claude Code, Cursor, Codex, LangChain, Agno, Strands, your own code…)
│ prompts · tool outputs · logs · RAG results · files
▼
┌────────────────────────────────────────────────────┐
│ Headroom (runs locally — your data stays here) │
│ ──────────────────────────────────────────────── │
│ CacheAligner → ContentRouter → CCR │
│ ├─ SmartCrusher (JSON) │
│ ├─ CodeCompressor (AST) │
│ └─ Kompress-base (text, HF) │
│ │
│ Cross-agent memory · headroom learn · MCP │
└────────────────────────────────────────────────────┘
│ compressed prompt + retrieval tool
▼
LLM provider (Anthropic · OpenAI · Bedrock · …)
- ContentRouter — detects content type, selects the right compressor
- SmartCrusher / CodeCompressor / Kompress-base — compress JSON, AST, or prose
- CacheAligner — stabilizes prefixes so provider KV caches actually hit
- CCR — stores originals locally; LLM calls
headroom_retrieveif it needs them
→ Architecture · CCR reversible compression · Kompress-v2-base model card
Get started (60 seconds)
# 1 — Install
pip install "headroom-ai[all]" # Python
npm install headroom-ai # Node / TypeScript
# 2 — Pick your mode
headroom wrap claude # wrap a coding agent
headroom proxy --port 8787 # drop-in proxy, zero code changes
# or: from headroom import compress # inline library
# 3 — See the savings
headroom perf
Granular extras: [proxy], [mcp], [ml], [code], [memory], [relevance], [image], [agno], [langchain], [evals], [pytorch-mps] (Apple-GPU memory-embedder offload — set HEADROOM_EMBEDDER_RUNTIME=pytorch_mps). Requires Python 3.10+.
Proof
Savings on real agent workloads:
| Workload | Before | After | Savings |
|---|---|---|---|
| Code search (100 results) | 17,765 | 1,408 | 92% |
| SRE incident debugging | 65,694 | 5,118 | 92% |
| GitHub issue triage | 54,174 | 14,761 | 73% |
| Codebase exploration | 78,502 | 41,254 | 47% |
Accuracy preserved on standard benchmarks:
| Benchmark | Category | N | Baseline | Headroom | Delta |
|---|---|---|---|---|---|
| GSM8K | Math | 100 | 0.870 | 0.870 | ±0.000 |
| TruthfulQA | Factual | 100 | 0.530 | 0.560 | +0.030 |
| SQuAD v2 | QA | 100 | — | 97% | 19% compression |
| BFCL | Tools | 100 | — | 97% | 32% compression |
Reproduce: python -m headroom.evals suite --tier 1 · Full benchmarks & methodology
Agent compatibility matrix
| Agent | headroom wrap |
Notes |
|---|---|---|
| Claude Code | ✅ | --memory · --code-graph |
| Codex | ✅ | shares memory with Claude |
| Cursor | ✅ | prints config — paste once |
| Aider | ✅ | starts proxy + launches |
| Copilot CLI | ✅ | starts proxy + launches |
| OpenClaw | ✅ | installs as ContextEngine plugin |
Any OpenAI-compatible client works via headroom proxy. MCP-native: headroom mcp install.
GitHub Copilot CLI subscription mode
Headroom can route GitHub Copilot CLI subscription traffic through the local proxy:
headroom wrap copilot --subscription -- --model gpt-4o
This lets Headroom intercept OpenAI-compatible Copilot CLI requests and apply the same proxy compression pipeline before forwarding to GitHub Copilot's hosted API. The wrapper resolves the account-specific Copilot API endpoint and prints it as COPILOT_PROVIDER_API_URL=... during launch.
Platform support note: macOS auth reuse via Copilot CLI Keychain storage has been smoke-tested. Windows Credential Manager, Linux Secret Service / secret-tool, and Docker/CI token-injection paths are implemented or planned as auth-discovery paths, but still need real OS validation before they should be considered fully vetted. For Docker and CI, prefer passing an explicit GITHUB_COPILOT_TOKEN or GITHUB_COPILOT_GITHUB_TOKEN rather than relying on host keychain access.
When to use · When to skip
Great fit if you…
- run AI coding agents daily and want savings without changing your code
- work across multiple agents and want shared memory
- need reversible compression — originals are retrievable via CCR within the configured TTL
Skip it if you…
- only use a single provider's native compaction and don't need cross-agent memory
- work in a sandboxed environment where local processes can't run
Integrations — drop Headroom into any stack
| Your setup | Hook in with |
|---|---|
| Any Python app | compress(messages, model=…) |
| Any TypeScript app | await compress(messages, { model }) |
| Anthropic / OpenAI SDK | withHeadroom(new Anthropic()) · withHeadroom(new OpenAI()) |
| Vercel AI SDK | wrapLanguageModel({ model, middleware: headroomMiddleware() }) |
| LiteLLM | litellm.callbacks = [HeadroomCallback()] |
| LangChain | HeadroomChatModel(your_llm) |
| Agno | HeadroomAgnoModel(your_model) |
| Strands | Strands guide |
| ASGI apps | app.add_middleware(CompressionMiddleware) |
| Multi-agent | SharedContext().put / .get |
| MCP clients | headroom mcp install |
What's inside
- SmartCrusher — universal JSON: arrays of dicts, nested objects, mixed types.
- CodeCompressor — AST-aware for Python, JS, Go, Rust, Java, C++.
- Kompress-base — our HuggingFace model, trained on agentic traces.
- Image compression — 40–90% reduction via trained ML router.
- CacheAligner — stabilizes prefixes so Anthropic/OpenAI KV caches actually hit.
- IntelligentContext — score-based context fitting with learned importance.
- CCR — reversible compression; LLM retrieves originals on demand.
- Cross-agent memory — shared store, agent provenance, auto-dedup.
- SharedContext — compressed context passing across multi-agent workflows.
headroom learn— plugin-based failure mining for Claude, Codex, Gemini.
Pipeline internals
Headroom exposes one stable request lifecycle across compress(), the SDK, and the proxy:
Setup → Pre-Start → Post-Start → Input Received → Input Cached → Input Routed → Input Compressed → Input Remembered → Pre-Send → Post-Send → Response Received
- Transforms do the work: CacheAligner, ContentRouter, SmartCrusher, CodeCompressor, Kompress-base, IntelligentContext / RollingWindow.
- Pipeline extensions observe or customize lifecycle stages via
on_pipeline_event(...). - Compression hooks sit alongside the canonical lifecycle as an additional extension seam.
- Proxy extensions remain the server/app integration seam for ASGI middleware, routes, and startup policy.
Provider and tool-specific behavior lives under headroom/providers/ so core orchestration stays focused on lifecycle, sequencing, and policy.
- CLI/tool slices:
headroom/providers/claude,copilot,codex,openclaw - Provider runtime slices:
headroom/providers/claude,gemini, plus shared backend/runtime dispatch inheadroom/providers/registry.py - Core files stay orchestration-first:
wrap.py,client.py,cli/proxy.py, andproxy/server.pydelegate provider-specific env shaping, API target normalization, backend selection, and transport dispatch.
Install
pip install "headroom-ai[all]" # Python, everything
npm install headroom-ai # TypeScript / Node
docker pull ghcr.io/chopratejas/headroom:latest
Granular extras: [proxy], [mcp], [ml] (Kompress-base), [code], [memory], [relevance], [image], [agno], [langchain], [evals], [pytorch-mps] (Apple-GPU memory-embedder offload — set HEADROOM_EMBEDDER_RUNTIME=pytorch_mps). Requires Python 3.10+.
Using pipx? Choose a supported interpreter explicitly:
pipx install --python python3.13 "headroom-ai[all]"
→ Installation guide — Docker tags, persistent service, PowerShell, devcontainers.
Corporate / SSL-inspection environments
If pip install "headroom-ai[all]" fails with CERTIFICATE_VERIFY_FAILED
(unable to get local issuer certificate), your network uses SSL inspection — a MITM
proxy presenting a company-issued CA. The build backend (maturin) downloads rustup over a
connection your TLS stack doesn't trust. Install Rust first so the build doesn't fetch it:
# macOS / Linux
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh && rustup default stable
# Windows
winget install Rustlang.Rustup && rustup default stable
Restart your shell, then pip install "headroom-ai[all]". A prebuilt wheel avoids the Rust
build entirely where available: pip install --only-binary headroom-ai headroom-ai.
Two runtime assets are fetched over TLS; if they are blocked, trust your corporate CA via
REQUESTS_CA_BUNDLE / SSL_CERT_FILE / CURL_CA_BUNDLE:
cdn.pyke.io— the ONNX Runtime for the Rust core. Alternatively pre-provide it withORT_STRATEGY=systemandORT_LIB_LOCATION=/path/to/onnxruntime.huggingface.co— thekompress-basecompression model. Pre-download it and run withHF_HUB_OFFLINE=1, or setHF_ENDPOINTto a trusted mirror.
Running with compression disabled (pure gateway) requires neither asset.
headroom learn
headroom learn — mines failed sessions, writes corrections to CLAUDE.md / AGENTS.md / GEMINI.md.
Documentation
| Start here | Go deeper |
|---|---|
| Quickstart | Architecture |
| Proxy | How compression works |
| MCP tools | CCR — reversible compression |
| Memory | Cache optimization |
| Failure learning | Benchmarks |
| Configuration | Limitations |
Compared to
Headroom runs locally, covers every content type, works with every major framework, and is reversible.
| Scope | Deploy | Local | Reversible | |
|---|---|---|---|---|
| Headroom | All context — tools, RAG, logs, files, history | Proxy · library · middleware · MCP | Yes | Yes |
| RTK | CLI command outputs | CLI wrapper | Yes | No |
| lean-ctx | CLI commands, MCP tools, editor rules | CLI wrapper · MCP | Yes | No |
| Compresr, Token Co. | Text sent to their API | Hosted API call | No | No |
| OpenAI Compaction | Conversation history | Provider-native | No | No |
Attribution. Headroom ships with the excellent RTK binary for shell-output rewriting —
git show --short, scopedls, summarized installers. Huge thanks to the RTK team; their tool is a first-class part of our stack, and Headroom compresses everything downstream of it. Headroom can also use lean-ctx as the selected CLI context tool; setHEADROOM_CONTEXT_TOOL=lean-ctxbefore runningheadroom wrap ....
Contributing
git clone https://github.com/chopratejas/headroom.git && cd headroom
pip install -e ".[dev]" && pytest
Devcontainers in .devcontainer/ (default + memory-stack with Qdrant & Neo4j). See CONTRIBUTING.md.
Community
- Discord — questions, feedback, war stories.
- Kompress-v2-base on HuggingFace — the model behind our text compression.
License
Apache 2.0 — see LICENSE.