headroom/README.md

  ██╗  ██╗███████╗ █████╗ ██████╗ ██████╗  ██████╗  ██████╗ ███╗   ███╗
  ██║  ██║██╔════╝██╔══██╗██╔══██╗██╔══██╗██╔═══██╗██╔═══██╗████╗ ████║
  ███████║█████╗  ███████║██║  ██║██████╔╝██║   ██║██║   ██║██╔████╔██║
  ██╔══██║██╔══╝  ██╔══██║██║  ██║██╔══██╗██║   ██║██║   ██║██║╚██╔╝██║
  ██║  ██║███████╗██║  ██║██████╔╝██║  ██║╚██████╔╝╚██████╔╝██║ ╚═╝ ██║
  ╚═╝  ╚═╝╚══════╝╚═╝  ╚═╝╚═════╝ ╚═╝  ╚═╝ ╚═════╝  ╚═════╝ ╚═╝     ╚═╝
                  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|copilot|cursor|aider|opencode|cline|continue|goose|openhands|openclaw|vibe in one command; undo with headroom unwrap <tool>
• MCP server — headroom_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.local.md (default, gitignored) or CLAUDE.md / AGENTS.md / GEMINI.md
• Output token reduction — trims what the model writes back (not just what you send): drops ceremony/restated code and skips deep "thinking" on routine steps. See Output token reduction.
• 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 — Verify setup and see the savings
headroom doctor                         # health check — confirms routing is working
headroom perf
headroom dashboard                      # live savings dashboard (proxy must be running)

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

Output token reduction (cut what the model writes back)

Everything above shrinks the prompt you send. But you also pay for every token the model writes back — and on Opus-class models output costs 5× input. A lot of that output is waste: "Great, let me…" preambles, re-printing code you just showed it, and deep "thinking" on routine steps like reading a file.

Headroom can trim that too, from the proxy, without you changing any code:

• Verbosity steering — appends a short "be terse, don't restate context" note to the end of the system prompt (so your prompt cache still hits).
• Effort routing — when a turn is just the model resuming after a tool result (a file read, a passing test), it dials the model's thinking effort down. New questions and errors keep full effort.

Turn it on:

export HEADROOM_OUTPUT_SHAPER=1     # off by default
headroom proxy --port 8787

Already running a proxy? These switches are read live on every request, so a proxy that headroom wrap reused (rather than started) would not see a value you export afterwards — its environment was snapshotted at launch. headroom wrap now hot-syncs your current settings to the running proxy via a loopback POST /admin/runtime-env, so they take effect immediately with no restart (no cold start, no dropped requests, no lost caches). Set them before you wrap. On a shared proxy these overrides are global — the last explicit setting wins.

Learn the right terseness for you. People don't say how terse they want answers — they show it (they interrupt long replies, or move on before they could have read them). headroom learn --verbosity reads your past sessions and picks the level automatically:

headroom learn --verbosity            # preview what it found (dry run)
headroom learn --verbosity --apply    # save it; the proxy uses it from now on

See how many output tokens you saved. Output savings are counterfactual — we never see what the model would have written — so Headroom reports an honest estimate with a confidence range, never a made-up number:

headroom output-savings
# Reduction: 31.7%  (95% CI 27.7% … 35.7%)   [estimated]

Want a measured number instead of an estimate? Leave 10% of conversations unshaped as a control group: export HEADROOM_OUTPUT_HOLDOUT=0.1. The dashboard shows an Output Tokens Saved card next to input compression, labelled measured or estimated with the confidence band.

→ Full write-up incl. the measurement methodology: docs/proposals/output-token-reduction.md

Agent compatibility matrix

Agent	headroom wrap	Notes
Claude Code	✅	--memory · --code-graph · --1m · --tool-search
Codex	✅	shares memory with Claude
Cursor	Manual setup	starts proxy and prints base URLs for Cursor settings
Aider	✅	starts proxy + launches
Copilot CLI	✅	starts proxy + launches
OpenClaw	✅	installs as ContextEngine plugin
OpenCode	✅	injects config · starts proxy + launches
Cline	✅	starts proxy + injects config
Continue	✅	starts proxy + injects config
Goose	✅	starts proxy + launches
OpenHands	✅	starts proxy + launches
Mistral Vibe	✅	starts proxy + launches
Cortex Code	✅	60–65% savings · library mode

Any OpenAI-compatible client works via headroom proxy. MCP-native: headroom mcp install. Undo durable wrapping with headroom unwrap <tool> (supports: claude, copilot, codex, opencode, openclaw).

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 — 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 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+.

Note

: [all] covers the core stack but excludes framework adapters. Install them separately: pip install "headroom-ai[langchain]" (also [agno], [strands], [anyllm], [bedrock]).

Using pipx? Choose a supported interpreter explicitly:

pipx install --python python3.13 "headroom-ai[all]"

Pick 3.13 if you want dollar savings. The dashboard's Proxy $ Saved tile prices compression with LiteLLM, and LiteLLM can't be installed on Python 3.14+. On 3.14 token savings still track, but the dollar figure stays $0.00. If you already installed on 3.14, switch with pipx reinstall headroom-ai --python python3.13 and restart the proxy.

→ Installation guide — Docker tags, persistent service, PowerShell, devcontainers.

Updating

headroom update          # detects pip / pipx / uv tool and upgrades in place
headroom update --check  # report the latest release without upgrading
headroom update --pre    # include pre-releases

headroom update figures out how Headroom was installed (pip/venv, pip --user, pipx, uv tool) and runs the matching upgrade across macOS, Linux, and Windows. For git checkouts, editable installs, Docker images, and externally-managed system Pythons (PEP 668) it prints the correct manual step instead of guessing.

The proxy also shows a one-line "update available" notice on startup. It checks PyPI at most once a day, in the background, and never blocks. Opt out with HEADROOM_UPDATE_CHECK=off (also skipped in --stateless mode and CI).

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. Prebuilt wheels are published for Windows (win_amd64), Linux (x86_64 / aarch64), and macOS (Apple Silicon), so installs on those platforms never need a local Rust toolchain — the Rust-first dance above is only for the platform-independent sdist fallback (e.g. Intel macOS).

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.

"Basic Constraints of CA cert not marked critical" (Python 3.13+ strict mode)

A different failure from the one above. If TLS fails with:

[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed:
Basic Constraints of CA cert not marked critical

then the corporate CA is found and trusted — adding it to a CA bundle changes nothing. Python 3.13 + OpenSSL 3.x enable VERIFY_X509_STRICT by default, which enforces RFC 5280 §4.2.1.9: a CA cert's basicConstraints must be marked critical. Inspection roots like Zscaler set CA:TRUE without the critical bit, so the chain is rejected.

Set HEADROOM_TLS_STRICT=0 to clear only the strict flag from every TLS context Headroom controls — the proxy's httpx upstream client and the urllib3/huggingface_hub path used for model downloads. Chain validation, signature, expiry, and hostname checks all stay on; this is strictly narrower than disabling verification.

HEADROOM_TLS_STRICT=0 headroom proxy --port 8787

The Rust core's ONNX download (cdn.pyke.io) uses a separate TLS stack (rustls / OS trust store), unaffected by HEADROOM_TLS_STRICT. On Windows the corporate root must be in the machine certificate store (browsers already trust it there); or pre-provision ONNX Runtime with ORT_STRATEGY=system + ORT_LIB_LOCATION=/path/to/onnxruntime to skip the download entirely.

headroom learn

headroom learn — mines failed sessions, writes corrections to CLAUDE.local.md (default, gitignored; use --target CLAUDE.md for the shared team file) / 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
Persistent installs (headroom init / headroom install apply)	Savings analytics (headroom savings / headroom perf / headroom doctor)

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

• Discord — questions, feedback, war stories.
• Kompress-v2-base on HuggingFace — the model behind our text compression.

License

Apache 2.0 — see LICENSE.