Phase B step 1 of the live-zone-only realignment. Removes ~10K LOC of
"drop messages from history" machinery that became unreachable after
PR-A1 made `/v1/messages` a passthrough on the proxy. Live-zone-only
compression (PR-B2..B7) operates on content blocks within messages;
message-list mutation no longer happens in the pipeline.
Python deletes:
- headroom/transforms/intelligent_context.py (1077 LOC)
- headroom/transforms/rolling_window.py (395 LOC)
- headroom/transforms/progressive_summarizer.py (508 LOC)
- headroom/transforms/scoring.py (459 LOC)
- headroom/transforms/tool_crusher.py (338 LOC)
- 5 corresponding tests/test_transforms/* and tests/test_proxy_intelligent_context.py
Rust deletes:
- crates/headroom-core/src/context/* (manager, config, workspace,
candidate, ccr_drop, strategy/, mod) + safety.rs replaced
- crates/headroom-core/src/scoring/* (mod, score, scorer, traits, weights)
- MessageScorerComparator from crates/headroom-parity (PR #338/#343
becomes deletable; sunk cost stays sunk)
- 13 message_scorer fixtures + record_message_scorer.py
Rust adds (move + rewrite):
- crates/headroom-core/src/transforms/safety.rs — `tool_pair_indices`
preserves the OpenAI/Anthropic tool_use ↔ tool_result pairing rule
the live-zone dispatcher (PR-B2) needs. No IcmConfig dependency.
Surface refactors:
- HeadroomConfig: drop `tool_crusher`, `rolling_window`,
`intelligent_context` fields; hoist `output_buffer_tokens` to top
level (used by client.py).
- ProxyConfig: drop `intelligent_context*` fields.
- `headroom wrap` proxy server: retire IntelligentContextManager
and RollingWindow imports + branch; pipeline is CacheAligner →
ContentRouter (smart_routing) or CacheAligner → SmartCrusher
(legacy).
- CLI: drop `--no-intelligent-context`, `--no-intelligent-scoring`,
`--no-compress-first` flags.
- LangChain memory integration: rename `_apply_rolling_window` →
`_apply_compression`, drop RollingWindowConfig dep. Threshold is
now advisory — B6 will rework the contract.
- TransformPipeline.create_pipeline now takes only cache_aligner_config.
- headroom/__init__.py + headroom/transforms/__init__.py: strip
exports of deleted symbols.
Bug fixes uncovered by full pytest sweep:
- providers/copilot/wrap.py: `environ or os.environ` collapsed
empty-dict to falsy → callers passing `environ={}` accidentally
pulled from os.environ. Use `environ if environ is not None else
os.environ`.
Test correctness fixes:
- _DummyAnthropicHandler._retry_request gains **_kwargs to match
the real handler signature post-A8.
- test_ws_http_fallback extracts JSON from `content=` (post-A3
byte-faithful) rather than the obsolete `json=` kwarg.
- test_ccr_response_handler_extra fixture joins SSE events with
`\n\n` per spec (post-A8 byte-buffer parser requirement).
- test_proxy_responses_phase_preservation: capture via direct
handler attached to the named logger, so the assertion is
order-independent (proxy `_setup_file_logging` flips
`headroom.propagate=False` once any earlier test triggers it).
- conftest.py autouse fixture resets `headroom.propagate=True`
before each test as a defensive measure for the same pollution.
- test_wrap_copilot_translated_backend_still_requires_byok:
monkeypatch.delenv every provider key so the BYOK error
actually fires.
- test_native_installers: skip when system bash < 4.3 (macOS ships 3.2).
- TestGeminiEmbedContent / TestGeminiBatchEmbedContents:
pytest.mark.skip — proxy currently has no :embedContent route;
feature gap, not regression.
Acceptance:
- cargo build --workspace + cargo clippy + cargo fmt --check: green.
- cargo test --workspace --exclude headroom-py: 777 passed.
- pytest: 4892 passed, 240 skipped, 0 failed.
- git grep returns only intentional comments referencing the deletion.
Per-PR-B1 plan: REALIGNMENT/04-phase-B-live-zone.md.
|
||
|---|---|---|
| .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 | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .pre-commit-config.yaml | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| CODE_OF_CONDUCT.md | ||
| codecov.yml | ||
| CONTRIBUTING.md | ||
| deny.toml | ||
| docker-bake.hcl | ||
| docker-compose.yml | ||
| Dockerfile | ||
| Headroom-2.gif | ||
| headroom-savings.png | ||
| headroom_learn.gif | ||
| HeadroomDemo-Fast.gif | ||
| LICENSE | ||
| Makefile | ||
| mkdocs.yml | ||
| NOTICE | ||
| PR.md | ||
| pyproject.toml | ||
| README.md | ||
| rust-toolchain.toml | ||
| RUST_DEV.md | ||
| SECURITY.md | ||
| uv.lock | ||
Every tool call, log line, DB read, RAG chunk, and file your agent injects into a prompt is mostly boilerplate. Headroom strips the noise and keeps the signal — losslessly, locally, and without touching accuracy.
100 logs. One FATAL error buried at position 67. Both runs found it. Baseline 10,144 tokens → Headroom 1,260 tokens — 87% fewer, identical answer.
python examples/needle_in_haystack_test.py
Quick start
Works with Anthropic, OpenAI, Google, Bedrock, Vertex, Azure, OpenRouter, and 100+ models via LiteLLM.
Wrap your coding agent — one command:
pip install "headroom-ai[all]"
headroom wrap claude # Claude Code
headroom wrap codex # Codex
headroom wrap cursor # Cursor
headroom wrap aider # Aider
headroom wrap copilot # GitHub Copilot CLI
Drop it into your own code — Python or TypeScript:
from headroom import compress
result = compress(messages, model="claude-sonnet-4-5")
response = client.messages.create(model="claude-sonnet-4-5", messages=result.messages)
print(f"Saved {result.tokens_saved} tokens ({result.compression_ratio:.0%})")
import { compress } from 'headroom-ai';
const result = await compress(messages, { model: 'gpt-4o' });
Or run it as a proxy — zero code changes, any language:
headroom proxy --port 8787
ANTHROPIC_BASE_URL=http://localhost:8787 your-app
OPENAI_BASE_URL=http://localhost:8787/v1 your-app
Why Headroom
- Accuracy-preserving. GSM8K 0.870 → 0.870 (±0.000). TruthfulQA +0.030. SQuAD v2 and BFCL both 97% accuracy after compression. Validated on public OSS benchmarks you can rerun yourself.
- Runs on your machine. No cloud API, no data egress. Compression latency is milliseconds — faster end-to-end for Sonnet / Opus / GPT-4 class models than a hosted service round-trip.
- Kompress-base on HuggingFace. Our open-source text compressor, fine-tuned on real agentic traces — tool outputs, logs, RAG chunks, code. Install with
pip install "headroom-ai[ml]". - Cross-agent memory and learning. Claude Code saves a fact, Codex reads it back.
headroom learnmines failed sessions and writes corrections straight toCLAUDE.md/AGENTS.md/GEMINI.md— reliability compounds over time. - Reversible (CCR). Compression is not deletion. The model can always call
headroom_retrieveto pull the original bytes. Nothing is thrown away.
Bundles the RTK binary for shell-output rewriting — full attribution below.
How it fits
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 · …)
→ Architecture · CCR reversible compression · Kompress-base model card
Canonical pipeline lifecycle
Headroom now 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 still do the work: CacheAligner, ContentRouter, SmartCrusher, CodeCompressor, Kompress-base, IntelligentContext / RollingWindow.
- Pipeline extensions observe or customize those lifecycle stages via
on_pipeline_event(...). - Compression hooks still work and now sit alongside the canonical lifecycle instead of being the only extension seam.
- Proxy extensions remain the server/app integration seam for ASGI middleware, routes, and startup policy.
Provider slices
Provider and tool-specific behavior is being moved behind dedicated modules 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.pynow delegate provider-specific env shaping, API target normalization, backend selection, and transport dispatch instead of inlining those rules.
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
Community, live:
→ Full benchmarks & methodology
Built for coding agents
| Agent | One-command wrap | Notes |
|---|---|---|
| Claude Code | headroom wrap claude |
--memory for cross-agent memory, --code-graph for codebase intel |
| Codex | headroom wrap codex --memory |
Shares the same memory store as Claude |
| Cursor | headroom wrap cursor |
Prints Cursor config — paste once, done |
| Aider | headroom wrap aider |
Starts proxy, launches Aider |
| Copilot CLI | headroom wrap copilot |
Starts proxy, launches Copilot |
| OpenClaw | headroom wrap openclaw |
Installs Headroom as ContextEngine plugin |
MCP-native too — headroom mcp install exposes headroom_compress, headroom_retrieve, and headroom_stats to any MCP client.
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.
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), [agno], [langchain], [evals]. Requires Python 3.10+.
→ Installation guide — Docker tags, persistent service, PowerShell, devcontainers.
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 (not just CLI or text), 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 |
| 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→git show --short, noisyls→ scoped, chatty installers → summarized. Huge thanks to the RTK team; their tool is a first-class part of our stack, and Headroom compresses everything downstream of it.
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
- Live leaderboard — 60B+ tokens saved and counting.
- Discord — questions, feedback, war stories.
- Kompress-base on HuggingFace — the model behind our text compression.
License
Apache 2.0 — see LICENSE.