Deus Witness
Checks every MCP tool call of your agent with an independent witness and gives signed receipts.
Installation
Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).
deus-witnessclaude mcp add deus-witness -e 'DEUS_WITNESS_KEY=<your deus_witness_key>' -e 'DEUS_WITNESS_URL=https://witness.sipkigroup.com' -- uvx deus-witness==0.2.40 -- '<upstream_command>'
{
"mcpServers": {
"deus-witness": {
"command": "uvx",
"args": [
"deus-witness==0.2.40",
"--",
"<upstream_command>"
],
"env": {
"DEUS_WITNESS_KEY": "<your deus_witness_key>",
"DEUS_WITNESS_URL": "https://witness.sipkigroup.com"
}
}
}
}
Variables d'environnement
DEUS_WITNESS_KEYobligatoire secret Agent key (dwk_...) created in your Deus Witness account.DEUS_WITNESS_URLWitness service URL.
Documentation
Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.
Sommaire
Deus Witness
An independent witness for AI-agent tool calls. Your agent asks before it acts; a witness that is not the agent's operator
checks the call against a mandate you signed, and answers allow, deny or defer (wait for you). Every answer is a signed,
append-only, independently verifiable receipt - so "what did the agent do, and who allowed it" has an answer you do not have to take on trust.
- Hosted service: https://witness.sipkigroup.com - live demo: https://witness.sipkigroup.com/demo
- This repository: the open parts - the receipt specification, two independent verifiers, the TypeScript client, the Python client and the HTTP API contract (OpenAPI, data only).
Status: early (0.x). The specification is an unpublished individual draft (not an IETF standard, not submitted anywhere). The evidence so far is our own simulations and independent implementations written inside one project; there are no external audits or deployments yet. Treat it as something to test and attack, not as a certified security boundary. Reports of bypasses are the most valuable thing you can send us.
What is here
| Path | What | License |
|---|---|---|
spec/ | Draft specification of the action receipt (draft-deus-aar-05, plus history and errata) and the test vectors (spec/vectors) | Apache-2.0 |
verifier_js/ | Independent clean-room verifier in JavaScript | Apache-2.0 |
verifier_swift/ | Independent clean-room verifier in Swift (source; build with ./build.sh) | Apache-2.0 |
sdk-ts/ | @deus-witness/sdk (npm): TypeScript client, no dependencies | Apache-2.0 |
python/ | deus-witness (PyPI): Python thin client - MCP proxy, Claude Code hook, doctor, SDK. Registry name io.github.sipkigroup/witness | Apache-2.0 |
contract/ | HTTP API contract (OpenAPI), WebAuthn signing profile, contract stub | Apache-2.0 |
integrations/ | Examples: Vercel AI SDK, curl | Apache-2.0 |
docs/ | Teams, recovery, anchors, verifying receipts | Apache-2.0 |
Not here: the Witness cloud service (server, web app, deployment). It is not open source. The hosted service is offered under separate
Terms of Use published on the website (not part of this license).
You can implement your own witness from spec/ and contract/.
Use it
The hosted service is at https://witness.sipkigroup.com. From TypeScript: npm install @deus-witness/sdk (see sdk-ts/README.md). From Python, or to put any MCP server behind the witness: pip install deus-witness or, with no install, uvx deus-witness -- <your MCP server command> (MCP Registry: io.github.sipkigroup/witness; see python/README.md; setup: https://witness.sipkigroup.com/dl/docs/quickstart.html).
Any other language: speak HTTP, see contract/openapi.yaml and integrations/.
Honest limits
- A witness cannot know what an action really does beyond what the tool map and the operator's description say; it checks the call against your mandate. Routes that do not go through the witness are not covered.
- The TypeScript client does not verify receipt signatures yet (the verifiers here do). Do not treat an
allowseen through it as cryptographically checked. - If the witness is unreachable, calls should be blocked (fail closed). That is a safety choice that costs availability.
Verify the receipts yourself
python3 spec/vectors/check_vectors.py # the abstract spec vectors through the reference model of the spec (no dependencies)
(cd verifier_js && npm ci && npm test) # the same vectors through the JavaScript verifier
(cd verifier_swift && ./build.sh && ./aarc --quiet --extra extra-vectors)
If two implementations disagree on a vector, one of them (or the spec) is wrong - please open an issue with the vector.
Security, contributing, license
- Vulnerabilities:
SECURITY.md(support@sipkigroup.com). Contributions:CONTRIBUTING.md. - Apache License 2.0 (
LICENSE,NOTICE). Copyright 2026 Sipki LLC.
Questions fréquentes
Qu'est-ce que Deus Witness ?
Checks every MCP tool call of your agent with an independent witness and gives signed receipts.
Comment installer Deus Witness ?
Il s'exécute sur votre machine. Dans Claude Code : claude mcp add deus-witness -e 'DEUS_WITNESS_KEY=<your deus_witness_key>' -e 'DEUS_WITNESS_URL=https://witness.sipkigroup.com' -- uvx deus-witness==0.2.40 -- '<upstream_command>'. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.
Faut-il une clé API pour Deus Witness ?
Oui. Il attend DEUS_WITNESS_KEY, à renseigner dans sa configuration.
Deus Witness est-il open source ?
Oui. Son code est sur GitHub sous licence Apache-2.0.
Qui maintient Deus Witness ?
Il est publié par sipkigroup. AI.tn le référence sans le maintenir ni le recommander.
Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.