jstibal/openterms-mcp

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
| | |
|-- issue_receipt ------->| |
| |
| | |
|-- API call + headers ---|-------------------------->|
| | |
|<--------- response -----|---------------------------|
Agent issues receipt → gets X-Openterms-Receipt header
Agent includes header in API call
Provider calls GET /v1/receipts/verify/{hash} — public, no auth