AgentContract Server

Smart contracts between AI agents. A Model Context Protocol (MCP) server for creating, managing, and enforcing binding agreements between AI agents with formal deliverables, deadlines, penalties, and a full lifecycle state machine.

Pricing

$19/month — Subscribe via Stripe

Features

• 🤝 Create contracts between two agents with deliverables, deadlines, payment, and milestones
• ✍️ Sign contracts — both parties must sign to activate
• 📋 Full contract lifecycle: draft → pending_signatures → active → completed / breached / terminated
• 📝 Propose amendments to active contracts
• 🚨 Report breaches with full audit trail
• 🔍 Query contracts and inspect status history
• 💾 Persistent storage — all contracts stored as JSON in ~/.agentcontracts/

Installation

pip install -r requirements.txt

Usage

Running the Server (stdio mode)

python server.py

The server communicates via STDIO transport and is designed to be launched by an MCP client (e.g., Claude Desktop, VS Code, or any MCP-compatible host).

MCP Client Configuration

Add to your MCP client config:

{
  "mcpServers": {
    "agent-contract": {
      "command": "python",
      "args": ["/path/to/agent-contract-mcp/server.py"]
    }
  }
}

Tools

1. contract_create

Create a new binding agreement between two agents.

Parameters:

Field	Type	Required	Description
parties	[string, string]	✅	Two agent IDs
terms.deliverables	[string]	✅	List of deliverables
terms.deadline	string (ISO 8601)	✅	Delivery deadline
terms.payment_amount	number	✅	Payment amount
terms.milestones	[string]	❌	Optional milestones
penalties.late_penalty	number	✅	Late delivery penalty
penalties.failure_penalty	number	✅	Failure penalty

Example:

{
  "parties": ["agent-alpha", "agent-beta"],
  "terms": {
    "deliverables": ["Research report on Q2 market trends", "Executive summary"],
    "deadline": "2026-06-01T00:00:00Z",
    "payment_amount": 5000,
    "milestones": ["Draft by May 15", "Final by June 1"]
  },
  "penalties": {
    "late_penalty": 100,
    "failure_penalty": 2500
  }
}

Returns: contract_id, status: "draft"

---

2. contract_get

Retrieve the full contract with all terms, signatures, amendments, and status history.

Parameters:

Field	Type	Required	Description
contract_id	string	✅	UUID of the contract

Returns: Complete contract object.

---

3. contract_sign

Sign a contract on behalf of an agent. The contract transitions through the lifecycle:

• 1st signature: draft → pending_signatures
• 2nd signature: pending_signatures → active

Parameters:

Field	Type	Required	Description
contract_id	string	✅	UUID of the contract
agent_id	string	✅	Agent performing the signature

Constraints:

• Agent must be a party to the contract
• Each agent can sign only once
• Contract must be in draft or pending_signatures status

---

4. contract_amend

Propose an amendment to an active contract. Amendments are recorded but do not automatically modify the original terms.

Parameters:

Field	Type	Required	Description
contract_id	string	✅	UUID of the contract
proposing_agent	string	✅	Agent proposing the change
changes	object	✅	Amendment details
changes.description	string	✅	Description of changes
changes.modified_terms	object	❌	Modified term values
changes.modified_penalties	object	❌	Modified penalty values

Constraints:

• Contract must be in active status
• Proposing agent must be a party to the contract

---

5. contract_status

Get the current lifecycle status of a contract with full history.

Parameters:

Field	Type	Required	Description
contract_id	string	✅	UUID of the contract

Returns: Status, human-readable description, parties, signatures, amendment count, breach record, and full status history timeline.

---

6. contract_report_breach

Report a breach of contract. Transitions status from active to breached.

Parameters:

Field	Type	Required	Description
contract_id	string	✅	UUID of the contract
breached_by	string	✅	Agent that breached
details	string	✅	Description of the breach

Constraints:

• Contract must be in active status
• Breached agent must be a party to the contract

Contract Lifecycle

                  ┌──────────┐
                  │   draft   │
                  └─────┬─────┘
                        │ 1st signature
                  ┌─────▼──────────┐
                  │ pending_signatures│
                  └─────┬──────────┘
                        │ 2nd signature
                  ┌─────▼────┐
                  │  active   │
                  └──┬───┬───┘
                     │   │
          ┌──────────┘   └──────────┐
          ▼                         ▼
    ┌──────────┐              ┌──────────┐
    │ completed│              │ breached  │
    └──────────┘              └──────────┘

    Any non-terminated state can transition to:
    ┌───────────┐
    │ terminated│
    └───────────┘

Storage

All contracts are stored as individual JSON files in ~/.agentcontracts/.

~/.agentcontracts/
├── <contract-uuid-1>.json
├── <contract-uuid-2>.json
└── ...

Each file contains the complete contract state including terms, signatures, amendments, breach records, and full status history.

Development

# Create virtual environment
python -m venv venv
source venv/bin/activate  # or `venv\Scripts\activate` on Windows

# Install dependencies
pip install -r requirements.txt

# Run the server
python server.py

License

MIT