Openterms

Open source cryptographic consent receipts + programmable guardrails + provider verification for AI agents.

Your agent proves what it agreed to. Your policy controls what it's allowed to do. The API provider can verify both.

License Tests

Live Demo · Quickstart · Self-Host · MCP Server · Contributing · Open Receipt Spec

What It Does

Openterms sits between your AI agent and the actions it takes. Three layers:

1. Receipts — Before your agent calls an API, it gets an Ed25519-signed receipt. Canonical JSON (RFC 8785), SHA-256 hash, real cryptography. Anyone can verify it using public keys — no API key needed, no trust in the server required.

2. Policy Engine — Daily spending caps, action type whitelists, escalation thresholds. The policy engine evaluates before the receipt is signed. Denied actions never get a receipt.

3. Provider Verification — API providers register their terms URL and verify agent consent before serving requests. One public GET call. Both sides of the transaction trust the proof.

Quickstart

60 seconds to your first receipt:

git clone https://github.com/jstibal/openterms.git

cd openterms

pip install flask pyjwt cryptography pyyaml

bash quickstart.sh

Or with Docker:

git clone https://github.com/jstibal/openterms.git

cd openterms

docker compose up --build

In another terminal:

bash quickstart.sh

Receipt issuance is free — no wallet, no deposit, no payment required.

Self-Host

Run your own Openterms instance:

Option 1: Direct

pip install flask pyjwt cryptography pyyaml

python run.py

Server at http://localhost:5000

Option 2: Docker

docker compose up --build

Option 3: Point MCP server at your instance

export OPENTERMS_API_URL=http://localhost:5000

python openterms_mcp_server.py

Everything runs locally. SQLite database, no external dependencies.

Hosted Service

Don't want to self-host? Use the hosted instance at openterms.com — same open source code, managed for you.

MCP Server

10 tools for AI agents:

Tool What it does

issue_receipt Signed receipt before any action, with provider verification headers

verify_receipt Verify receipt cryptographic integrity (public)

verify_receipt_by_hash Look up and verify by canonical hash (public)

check_balance Workspace balance

get_pricing Per-receipt pricing

list_receipts Recent receipts

get_policy Active guardrails — call on startup

simulate_policy Pre-check: would this action be allowed?

policy_decisions Audit trail of every allow/deny/escalate

provider_activity Receipt stats for your API (provider auth)

MCP Config

{

"mcpServers": {

"openterms": {

"command": "python3",

"args": ["openterms_mcp_server.py"],

"env": {

"OPENTERMS_API_URL": "https://openterms.com",

"OPENTERMS_API_KEY": "openterms_your_key_here"

}

}

}

}

How Provider Verification Works

Agent Openterms API Provider

Agent issues receipt → gets X-Openterms-Receipt header

Agent includes header in API call

Provider calls GET /v1/receipts/verify/{hash} — public, no auth

Valid → serve. Invalid → reject.

API Endpoints

Core

Method Path Auth Description

POST /v1/receipts Bearer Issue signed receipt

POST /v1/receipts/verify None Verify receipt

GET /v1/receipts/verify/{hash} None Verify by hash

GET /v1/receipts Bearer List receipts

GET /.well-known/jwks.json None Public signing keys

Policy Engine

Method Path Auth Description

GET /v1/policy Bearer Active policy

PUT /v1/policy Admin Create/update policy

POST /v1/policy/simulate Bearer Test hypothetical action

GET /v1/policy/decisions Bearer Decision audit trail

Provider Verification

Method Path Auth Description

POST /v1/providers None Register as provider

POST /v1/providers/verify Provider Verify domain

GET /v1/provider/stats Provider Receipt stats

GET /v1/provider/receipts Provider Recent receipts

Tests

make test

120 tests passing (80 core + 40 provider verification)

Architecture

openterms/

├── app.py # Flask API (1135 lines)

├── db.py # SQLite database (15 tables)

├── openterms_mcp_server.py # MCP server + CLI (10 tools)

├── core/

│ ├── canonical.py # RFC 8785 canonicalization

│ └── signing.py # Ed25519 signing + JWKS

├── services/

│ ├── receipt_service.py # Receipt pipeline

│ ├── ledger_service.py # Balance tracking

│ └── policy_engine.py # Rule evaluation

├── tests/

│ ├── test_core.py # 80 tests

│ └── test_mvp3.py # 40 tests

├── Dockerfile

├── docker-compose.yml

├── quickstart.sh

└── .env.example

Roadmap

Phase Status What it does

MVP1 ✅ Shipped Signed receipts — record what happened

MVP2 ✅ Shipped Policy engine — enforce what's allowed

MVP3 ✅ Shipped Provider verification — both sides trust the proof

ORS Spec 🔄 In progress Open Receipt Specification — portable format

Integrations 🔄 In progress LangChain, CrewAI one-line callbacks

MVP4 Planned Receipt chaining, agent certification

Contributing

See CONTRIBUTING.md. We especially welcome framework integrations, language SDKs, and feedback on the Open Receipt Specification.

License

Apache 2.0 — see LICENSE.

Copyright 2026 Staticlabs Inc.