Seal your first AI decision in 60 seconds

The Causal Seal is an open format — implement it in any language. The fastest way to start is the zero-dependency Python reference implementation.

1 · Install

pip install causal-seal

One module, standard library only, Python 3.10+. View on PyPI.

2 · Emit a seal

Attach a seal to any generated output. Put in the causal state only what genuinely governed the decision — the causality criterion: had it been different, the output could have been different.

# emit.py
from causal_seal import emit_seal

seal = emit_seal(
    emitter="my-app/1.0",
    causal_state={
        "identity.expert":  "legal-assistant",
        "engine.model":     "gpt-4o",
        "shaping.guard":    "nominal",
        "context.memory_state": "awake",
    },
    output_text="The statute of limitations is six years.",
    dictionary="https://my-app.example/causal-dictionary.json",
)
print(seal["fingerprint"])

3 · Verify a seal

# verify.py
from causal_seal import verify_seal

ok, reason = verify_seal(seal, "The statute of limitations is six years.")
print(ok, reason)
# True  seal verified (Level 1 + output binding)

From the command line

causal-seal demo                         # emit + self-verify a sample seal
causal-seal verify seal.json --output-file out.txt
causal-seal selftest                     # check against the test vectors

Zero code: the gateway

Don't want to touch your app at all? Put the Causal Seal Gateway in front of your model — a drop-in, OpenAI-compatible proxy. Every response comes back sealed (streaming included), with no code change:

docker run -p 8080:8080 -e CAUSAL_UPSTREAM=https://api.openai.com causal-seal-gateway
# then point your app at it:
OPENAI_BASE_URL=http://localhost:8080

Non-streaming responses carry the seal in an X-Causal-Seal header; streaming responses get a final event: causal-seal just before [DONE]. A proxy seals what it observes from the outside (a thin seal); a rich seal needs a governance layer upstream.

No install? Verify in the browser

Auditors and reviewers can check any seal with zero setup — the browser verifier runs entirely client-side and sends nothing anywhere.

Any language

Nothing here is Python-specific. The format is: canonicalize the seal with RFC 8785 (JCS), hash with SHA-256. To implement an emitter or verifier in your stack, validate it against the schema and the computed test vectors:

Questions, issues, or a domain profile to propose? Open an issue on GitHub. Contributions welcome — see the neutrality charter for how the standard stays a common good.