headroom/README.md
Joel Belanger 0b4a4bd483
fix: support Copilot Business subscription auth (#641)
## Description

Adds a first-party `headroom copilot-auth login` flow for Copilot
subscription
mode and uses the resulting Copilot OAuth token to perform GitHub's
Copilot
token exchange before launching the wrapped Copilot CLI.

This fixes Business/Enterprise Cloud accounts where a generic
GitHub/Copilot
token can read Copilot account metadata but is rejected by the Copilot
token
exchange endpoint. It also avoids treating GitHub.com Enterprise Cloud
account
URLs such as `github.com/enterprises/acme` as API hostnames.

Fixes #635
Related: #488, #610
Builds on #576

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [x] New feature (non-breaking change that adds functionality)
- [x] Documentation update
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- Adds `headroom copilot-auth login` and `headroom copilot-auth status`.
- Stores a Headroom-specific Copilot OAuth token under Headroom's state
dir.
- Exchanges reusable Copilot OAuth tokens with Copilot Chat-compatible
headers before subscription-mode launch.
- Carries the resolved Copilot API endpoint into `headroom wrap copilot
--subscription`.
- Handles GitHub.com Enterprise Cloud URLs without synthesizing invalid
`api.github.com/enterprises/...` hosts.
- Adds focused unit tests and README guidance for subscription login.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [ ] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```console
ruff check headroom/copilot_auth.py headroom/cli/copilot_auth.py headroom/cli/main.py headroom/cli/__init__.py headroom/cli/wrap.py tests/test_copilot_auth.py tests/test_cli/test_copilot_auth.py tests/test_cli/test_wrap_copilot.py tests/test_copilot_subscription_smoke.py
# All checks passed!

ruff format --check headroom/copilot_auth.py headroom/cli/copilot_auth.py headroom/cli/main.py headroom/cli/__init__.py headroom/cli/wrap.py tests/test_copilot_auth.py tests/test_cli/test_copilot_auth.py tests/test_cli/test_wrap_copilot.py tests/test_copilot_subscription_smoke.py
# 9 files already formatted

python -m py_compile headroom/copilot_auth.py headroom/cli/copilot_auth.py headroom/cli/main.py headroom/cli/__init__.py headroom/cli/wrap.py tests/test_copilot_auth.py tests/test_cli/test_copilot_auth.py tests/test_cli/test_wrap_copilot.py tests/test_copilot_subscription_smoke.py

uv run --no-project --with pytest --with pytest-asyncio --with click --with rich --with opentelemetry-api --with pydantic --with tiktoken --with 'litellm==1.82.3' --with fastapi --with uvicorn --with 'httpx[http2]' --with openai --with mcp --with magika --with zstandard --with websockets --with onnxruntime --with transformers --with watchdog --with sqlite-vec pytest tests/test_copilot_auth.py tests/test_cli/test_copilot_auth.py tests/test_cli/test_wrap_copilot.py tests/test_cli_proxy_env.py tests/test_copilot_subscription_smoke.py
# 127 passed
```

Local note: `uv run pytest ...` against the project currently fails
before
running tests because `uv.lock` has an unrelated `gitpython`
wheel/version
mismatch.

## Manual Validation

I tested this with an existing GitHub Copilot Business subscription
associated with a GitHub.com Enterprise Cloud account.

The Enterprise Cloud value I tested was in the form:

```text
github.com/enterprises/<enterprise>
```

The tested flow was:

```text
headroom copilot-auth login
headroom wrap copilot --subscription -- --model gpt-5.4
```

This validated that Headroom does not treat
github.com/enterprises/<enterprise> as a Copilot API hostname. Instead,
token exchange uses GitHub.com and Headroom routes subscription-mode
traffic to the Copilot API endpoint returned by GitHub for the signed-in
account.

I did not test this with GitHub Enterprise Server or a custom enterprise
domain such as ghe.example.com.

No tokens, request IDs, or organization-specific identifiers are
included in this PR.

## Real Behavior Proof

- Environment: macOS Darwin, Python 3.12.7, local checkout on
`codex/copilot-business-auth`.
- Exact command / steps: Ran `headroom copilot-auth login`, then
launched `headroom wrap copilot --subscription -- --model gpt-5.4` with
a GitHub Copilot Business subscription tied to a GitHub.com Enterprise
Cloud account.
- Observed result: Headroom did not treat
`github.com/enterprises/<enterprise>` as a Copilot API hostname; token
exchange used GitHub.com and subscription traffic was routed to the
Copilot API endpoint returned for the signed-in account. The latest
focused Copilot auth/proxy tests pass locally (`127 passed`).
- Not tested: GitHub Enterprise Server or custom enterprise domains such
as `ghe.example.com`; Windows Credential Manager integration still needs
confirmation from someone on Windows.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing targeted unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Screenshots (if applicable)

N/A

## Additional Notes

Acknowledgement: the OAuth/token-exchange behavior was informed by
`anomalyco/opencode-copilot-auth` by Aiden Cline.

No tokens are printed by the new login/status commands; only a short
SHA-256
fingerprint is displayed for troubleshooting.

The interactive login is included because the missing piece is not just
an
Enterprise URL or routing hint. For GitHub.com Enterprise Cloud
accounts,
URLs like `github.com/enterprises/acme` identify the enterprise account
but
are not Copilot API hostnames; token exchange still happens through
GitHub.com
and then returns the account-specific Copilot API endpoint. A
command-line
enterprise argument can help for true GitHub Enterprise
Server/custom-domain
deployments, but it cannot produce the Copilot OAuth token class that
the
token-exchange endpoint accepts.

Ideally, Headroom would avoid an extra interactive login and reuse an
existing
GitHub/Copilot CLI session everywhere. In practice, some
reusable-looking
tokens can read Copilot account metadata but are rejected by Copilot
token
exchange, which leaves Business/Enterprise Cloud users with missing
model
catalogs. The explicit login command is the smallest independent way to
obtain
and persist the token needed for that exchange without asking users to
pass a
secret on the command line.

---------

Co-authored-by: jbelanger <your-username@users.noreply.github.com>
2026-06-12 20:46:38 -05:00

20 KiB
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                  The context compression layer for AI agents

6095% fewer tokens · library · proxy · MCP · 6 algorithms · local-first · reversible

CI codecov PyPI npm Model: Kompress-v2-base License: Apache 2.0 Docs

Docs · Install · Proof · Agents · Discord · llms.txt · Enterprise

AI agents / LLMs: read /llms.txt here, or fetch the live index / full docs blob.


chopratejas%2Fheadroom | Trendshift

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.

Headroom in action
Live: 10,144 → 1,260 tokens — same FATAL found.

What it does

  • Librarycompress(messages) in Python or TypeScript, inline in any app
  • Proxyheadroom proxy --port 8787, zero code changes, any language
  • Agent wrapheadroom wrap claude|codex|cursor|aider|copilot in one command
  • MCP serverheadroom_compress, headroom_retrieve, headroom_stats for any MCP client
  • Cross-agent memory — shared store across Claude, Codex, Gemini, auto-dedup
  • headroom learn — mines failed sessions, writes corrections to CLAUDE.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_retrieve if 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

Star History Chart

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 copilot-auth login
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 exchanges Headroom's reusable GitHub OAuth token for Copilot's short-lived API token and prints the upstream endpoint as COPILOT_PROVIDER_API_URL=... during launch.

headroom copilot-auth login stores a Headroom-specific Copilot OAuth token. This avoids relying on generic GitHub or Copilot CLI tokens that can read Copilot account metadata but may still be rejected by Copilot's token-exchange endpoint.

For GitHub Enterprise Server or custom-domain Copilot deployments, set the deployment domain before launching:

export GITHUB_COPILOT_ENTERPRISE_DOMAIN=ghe.example.com

For GitHub.com Enterprise Cloud URLs such as github.com/enterprises/your-enterprise, do not set an enterprise-domain override. Headroom uses GitHub's normal token-exchange endpoint and the Copilot API endpoint advertised for the signed-in account.

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 — 4090% 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:

SetupPre-StartPost-StartInput ReceivedInput CachedInput RoutedInput CompressedInput RememberedPre-SendPost-SendResponse 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 in headroom/providers/registry.py
  • Core files stay orchestration-first: wrap.py, client.py, cli/proxy.py, and proxy/server.py delegate 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 with ORT_STRATEGY=system and ORT_LIB_LOCATION=/path/to/onnxruntime.
  • huggingface.co — the kompress-base compression model. Pre-download it and run with HF_HUB_OFFLINE=1, or set HF_ENDPOINT to a trusted mirror.

Running with compression disabled (pure gateway) requires neither asset.

headroom learn

headroom learn in action

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, scoped ls, 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; set HEADROOM_CONTEXT_TOOL=lean-ctx before running headroom wrap ....

Contributing

git clone https://github.com/chopratejas/headroom.git && cd headroom
uv sync --extra dev && uv run pytest

Devcontainers in .devcontainer/ (default + memory-stack with Qdrant & Neo4j). See CONTRIBUTING.md.

Community

License

Apache 2.0 — see LICENSE.