tok-protocol 0.1.8

Bridge-first CLI and runtime for Claude Code that compresses conversations and exposes savings and fallback health

Tok

Tok is a local Claude Code bridge for deterministic context compression. It sits between Claude Code and the upstream model API, reduces repeated file/search/tool context when it can do so safely, and fails open to normal uncompressed behavior when fidelity is at risk.

Tok 0.1.x is deliberately narrow: Claude Code routed through a local bridge. It is not a hosted service, agent framework, repo indexer, or general prompt-compression SDK.

Quickstart

pip install tok-protocol
tok claude

Then, from another shell or after the session:

tok bridge status         # check bridge health
tok doctor                # explain current session state
tok stats                 # view savings
tok bridge stop           # stop cleanly

If you want an isolated CLI install and already use pipx, this works too:

pipx install tok-protocol
tok claude

tok claude starts the bridge if needed, routes Claude Code through it, and leaves your shell rc files untouched. If you prefer legacy auto-routing, opt in explicitly:

tok install --wrap-claude
source ~/.zshrc           # or source ~/.bashrc
claude

What Success Looks Like

A healthy bridge session usually has:

• tok bridge status showing the bridge running and Tok active
• tok doctor ending with Recommendation: keep Tok on
• tok stats showing With Tok vs without Tok, saved tokens, and estimated savings
• Degraded to baseline set to no

Representative output:

Bridge running on :9090 (PID 12345)
Saved $0.0123 - 48.1% saved
Verdict                Tok active and helping
Tok active             yes
Degraded to baseline   no
Fallbacks              0

If Degraded to baseline: yes or fallback counts rise, Tok protected the session by serving requests without compression.

What Changed In 0.1.7

Tok 0.1.7 adds the first visible trace/audit layer around the supported bridge path:

• tok audit validates draft Tok Trace files and live bridge sidecars.
• TOK_TRACE=1 writes opt-in metadata-only trace JSONL under ~/.tok/traces/.
• TOK_TRACE_CAPTURE_ARTIFACTS=1 writes sanitized metadata artifacts so tok audit can verify local hashes and byte sizes without storing raw prompts, responses, or tool outputs.
• New adversarial bridge-pressure tests cover large repeated reads, audit-heavy turns, overcompression risk, final-answer repair guards, and tool-pairing repair signals.

This is draft trace/audit groundwork, not universal protocol stability. Tok Capability, Tok Session, resolver networking, binary encodings, and agent-to-agent protocol behavior remain future work.

Trace Audit

Enable trace sidecars only when you want to inspect what Tok did:

TOK_TRACE=1 TOK_TRACE_CAPTURE_ARTIFACTS=1 tok bridge start
tok claude
tok audit --latest

Trace mode is local. Tok does not send trace files to the model provider, and the 0.1.8 live trace path does not store raw prompts, responses, or tool outputs. Live session_id values are trace-local ids, not durable client ids across bridge restarts.

tok audit is useful for checking bridge behavior and exactness metadata. It is not a general protocol compliance certificate.

Why Tok Exists

Long-running coding-agent sessions often resend verbose transcripts, file reads, search results, and tool outputs on every turn. That is useful when a human reads the output, but wasteful when the next reader is another model.

Tok tests a smaller runtime shape: compact, deterministic, model-facing state at the machine-to-machine boundary, with human-facing output preserved at the edges. Compression is rule-based rather than LLM-summarized, so behavior is repeatable and auditable.

What Tok Does

• Semantic deduplication: repeated file reads, search results, and tool outputs can be cached and replaced with compact references.
• Delta compression: changed content can be represented as a diff instead of a full repeated payload.
• Bounded rolling state: recent context stays available without unbounded history growth.
• Fail-open safety: when compression would risk fidelity, Tok serves the request in baseline mode and reports the fallback.
• Diagnostics: status, doctor, stats, logs, and optional trace audit explain what happened.

Savings

Savings are workload-dependent. Tok tends to help most on sustained sessions with repeated file reads, repeated searches, large tool outputs, or long-running debugging loops. Very short sessions may intentionally run near baseline because compression overhead is not worth paying.

Here is an upper-bound tok stats example from a long, highly repetitive 207-call session. It is not typical:

Use these as practical expectations:

• Sustained sessions: meaningful input-token savings when context repeats.
• Short sessions: little or no visible savings; Tok may stay baseline.
• Risky compression cases: fallback is preferred over corrupting context.

Pricing estimates depend on provider/model rates. See docs/pricing_verification.md and docs/claims_matrix.md for the current evidence trail.

Prerequisites

• Python 3.10 or newer
• macOS or Linux
• Claude Code installed and available as claude
• Claude Code already configured with provider credentials

Tok is a local proxy. It does not manage API keys. If Claude Code works without Tok, tok claude should work too.

Supported Surface

The public 0.1.x workflow is:

tok init
tok install
tok claude
tok bridge status
tok doctor
tok stats
tok audit --latest
tok bridge stop

The supported mode is the default tool-compatible bridge mode. For comparison or debugging, you can run without compression:

TOK_MODE=baseline tok bridge start
ANTHROPIC_BASE_URL=http://localhost:9090 claude
tok stats

For advanced routing or compatibility checks, you can still run the bridge and route a client explicitly:

tok bridge start
ANTHROPIC_BASE_URL=http://localhost:9090 <your-client-command>

That path is useful for debugging and experiments, but the low-friction public install story is pip install tok-protocol followed by tok claude.

Experimental Python submodule APIs and internal compression features exist, but they are not part of the supported 0.1.x contract and may change without compatibility guarantees.

Troubleshooting

Symptom	Check first	Likely fix
tok: command not found	Was the package installed in the active Python environment?	Re-activate the environment and run pip install tok-protocol.
claude: command not found after wrapper install	Did your shell reload?	Run source ~/.zshrc or source ~/.bashrc, or open a new shell.
Bridge not running	Did tok bridge start succeed?	Restart with tok bridge start --foreground and inspect tok bridge logs.
No savings visible yet	Is the session short or non-repetitive?	Keep working for a few turns, then run tok doctor and tok stats --last-session.
Degraded to baseline: yes	Did Tok fall back for safety?	Start with tok doctor, then follow docs/troubleshooting.md.

Install Verification

Use this for a clean package sanity check:

python -m venv .venv
source .venv/bin/activate
pip install tok-protocol
tok --version
tok --help
tok claude --help
tok install
tok bridge start --help
tok bridge status --help
tok stats --help
tok audit --help

For local checkout work:

pip install .
tok --version
tok --help

Docs Map

Start here:

• docs/bridge.md: full bridge tutorial
• docs/cli-reference.md: supported CLI surface
• docs/troubleshooting.md: fallback, logs, degraded sessions, savings interpretation
• docs/diagnostics.md: detailed bridge health signals

For release and architecture context:

• CHANGELOG.md: release notes
• docs/public-release-decision.md: supported workflows, limitations, and release bar
• docs/spec/README.md: Tok Trace draft specification map
• docs/architecture.md: current architecture
• docs/architecture-0.2.md: roadmap, not the current runtime contract
• docs/production-readiness.md: advanced release posture

Repo Map

• src/tok/: runtime, bridge, CLI, and library code
• docs/: public product docs plus release/reference docs
• docs/spec/: draft Tok Trace and protocol-layer specification work
• docs/maintainers/: maintainer roadmap and planning notes
• examples/: experimental wrapper/API examples outside the default bridge-first path
• tests/: unit, integration, replay, smoke, and stability coverage

Development

For maintainer validation:

uv sync --frozen --extra dev
uv run pre-commit run --all-files
uv run ruff check src/tok tests
uv run mypy src/tok
uv run pytest tests/unit tests/integration -v --cov=src/tok --cov-fail-under=80
uv build

For release-specific checks, see docs/release-checklist.md and docs/CICD_INTEGRATION.md.

Privacy

Tok runs locally. No data leaves your machine except the model/API calls Claude Code would already make. Optional 0.1.7 trace sidecars are local metadata files and do not store raw prompts, responses, or tool outputs by default.

Support Tok

Tok exists because repeated machine-facing context is a real cost in long coding-agent sessions. The most useful support is practical feedback:

• Star the repo and share it with developers who use Claude Code heavily.
• File issues with bridge logs, tok doctor, and tok stats output.
• Share benchmark results from real sustained sessions.
• Contribute docs, tests, or focused fixes.