Examples
Working examples grouped by evaluator outcome. Each is self-contained and runnable from the examples/ directory. See Start Here to find the right path for your use case.
Find the right example
HTTP 402 Payment Flow
A Node.js server that returns HTTP 402 Payment Required, accepts payment via x402, and issues Ed25519-signed PEAC receipts. Demonstrates the full Declare-Negotiate-Verify cycle.
- HTTP 402 response with payment details
- x402 payment verification
- Ed25519 receipt signing
- Receipt header in response
Pay-per-Inference
Shows how an AI agent handles 402 responses, obtains payment receipts, and retries requests with the PEAC-Receipt header. Includes retry logic and error handling.
- Agent-side 402 handling
- Receipt acquisition flow
- Retry with receipt header
- toCoreClaims() normalization
Pay-per-Crawl
Demonstrates how AI crawlers can evaluate publisher policies, respect access terms, and obtain receipts. Useful for compliance evidence and audit trails.
- Policy evaluation
- Purpose-based access control
- Receipt for audit trails
- Evidence generation for audit workflows
RSL Collective Licensing
Maps RSL (Robots Specification Language) tokens to PEAC ControlPurpose values. Shows how to integrate with collective licensing organizations.
- RSL token parsing
- ControlPurpose mapping
- Collective license integration
- Usage rights verification
MCP Paid Tools
Implements paid MCP tools with per-call and daily budget limits. Uses bigint minor units for precise currency handling.
- MCP tool integration
- Per-call pricing
- Budget enforcement
- Bigint minor units
OpenTelemetry Integration
Connects PEAC receipt issuance and verification to OpenTelemetry for observability. Supports privacy modes: strict, balanced, and custom attribute filtering.
- W3C Trace Context
- Privacy-preserving spans
- Metrics emission
- Custom attribute filtering
OpenClaw Interaction Evidence
Capture OpenClaw agent tool calls as signed PEAC interaction evidence receipts. Uses activate() for one-call setup with FileSpoolStore for durable storage.
- activate() one-call setup
- Two-stage pipeline
- FileSpoolStore durability
- Tamper-evident chain
MCP Server for AI Agents
Run the PEAC MCP server in Claude Desktop or Cursor to verify, inspect, decode, issue, and bundle receipts directly from AI agent conversations.
- peac_verify tool
- peac_inspect tool
- peac_issue (privileged)
- peac_create_bundle (privileged)
Paymentauth Evidence
Parse HTTP 402 challenges and receipts from the Payment authentication scheme. Demonstrates envelope-first parsing, raw artifact preservation, and coexistence with the PEAC-Receipt header.
- Challenge + Credential + Receipt parsing
- Raw + normalized dual representation
- Carrier coexistence with PEAC-Receipt
- receipt_ref via sha256(raw_header_value)
Paymentauth JSON-RPC
Demonstrates structured error handling for paymentauth in JSON-RPC transports including MCP. Uses error codes -32042 (payment required) and -32043 (payment failed).
- JSON-RPC error code -32042
- JSON-RPC error code -32043
- MCP extraction functions
- Structured error responses
ACP Session Lifecycle
Demonstrates the strict two-function boundary in ACP evidence: fromACPSessionLifecycleEvent for access evidence, fromACPPaymentObservation for commerce evidence with explicit observed_payment_state.
- Session lifecycle evidence
- Payment observation boundary
- Explicit observed_payment_state
- Commerce event only from payment artifacts
Stripe SPT Delegation
Shows how Stripe Payment Token delegation events (granted, presented, deactivated) are recorded separately from payment intent observations. Only fromStripePaymentIntentObservation produces commerce events.
- SPT delegation lifecycle
- Payment intent observation
- Explicit payment state requirement
- Settlement vs authorization mapping
Commerce Evidence Bundle
Bundle commerce evidence from multiple rails into a portable audit archive. Uses the experimental peac.commerce-bundle/0.1-experimental format with recursive stable serialization.
- Cross-rail evidence bundling
- Portable audit archive
- Deterministic serialization
- Offline verification
x402 Dual-Header Read
Demonstrates extractReceiptArtifactFromHeaders reading PEAC-Receipt, PAYMENT-RESPONSE (v2), and X-PAYMENT-RESPONSE (v1) headers with upstream artifact separation.
- v1/v2 header priority
- Upstream artifact separation
- receipt_jws vs upstreamArtifact
- isPeacReceipt discriminator
Clone the repository and run any example with a few commands:
# Clone the repository git clone https://github.com/peacprotocol/peac.git cd peac # Install dependencies pnpm install # Run an example cd examples/x402-node-server pnpm tsx demo.ts