Agent-to-Agent (A2A) Payments

Conto supports direct payment requests between registered agents. One agent creates a request and the paying agent reviews and executes it, subject to its policies and wallet limits.

A2A endpoints enforce explicit API-key scopes: payments:request to create, payments:approve to approve or reject, payments:execute to settle, transactions:read to list or inspect, and analytics:read for statistics.

How It Works

Requesting agent -> creates request -> target agent reviews -> target agent executes

Agent A calls POST /api/sdk/a2a/request
Agent B either receives a payment_request.created webhook or lists incoming requests via GET /api/sdk/a2a/requests
Agent B approves via POST /api/sdk/a2a/requests/{id}/approve or rejects via POST /api/sdk/a2a/requests/{id}/reject
Agent B executes the approved request via POST /api/sdk/a2a/requests/{id}/execute
The transfer still runs through Conto policy evaluation before settlement

Create a Request

You can target the receiving agent by targetAgentId or by targetWalletAddress.

curl -X POST https://conto.finance/api/sdk/a2a/request \
  -H "Authorization: Bearer $CONTO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "targetAgentId": "cmm5a0agt001m49h7bjqza22q",
    "amount": 50,
    "currency": "USDC",
    "purpose": "Reimbursement for API credits",
    "invoiceId": "INV-2026-001",
    "dueDate": "2026-08-01T00:00:00.000Z"
  }'

Response

{
  "success": true,
  "paymentRequest": {
    "id": "cmm5h1a2a001m49h7irxzh22q",
    "status": "review_required",
    "direction": "outgoing",
    "requestingAgent": {
      "id": "cmm59z8fj000l49h7bjqza11p",
      "name": "Purchasing Agent"
    },
    "requestedFromAgent": {
      "id": "cmm5a0agt001m49h7bjqza22q",
      "name": "DevOps Agent"
    },
    "amount": 50,
    "currency": "USDC",
    "purpose": "Reimbursement for API credits",
    "invoiceId": "INV-2026-001",
    "dueDate": "2026-08-01T00:00:00.000Z",
    "expiresAt": "2026-08-07T00:00:00.000Z",
    "links": {
      "details": "/api/sdk/a2a/requests/cmm5h1a2a001m49h7irxzh22q"
    }
  },
  "message": "Payment request sent to DevOps Agent"
}

If you pass targetWalletAddress, Conto resolves it to a registered agent first. Requests to unknown addresses are rejected.

List Requests

GET /api/sdk/a2a/requests?direction=incoming&status=review_required&limit=50&offset=0

Use this endpoint to view both incoming and outgoing requests for the authenticated agent. The direction filter accepts incoming, outgoing, or all. List and detail responses use these request statuses:

Status	Meaning
`review_required`	Waiting for the paying agent to review
`approved`	Approved and ready to execute
`declined`	Declined or cancelled
`processing`	Payment is in progress
`completed`	Payment completed successfully
`failed`	Payment processing failed
`expired`	The request expired

When a transaction is present, its status is processing, completed, or failed. Its stable transaction ID, network, block number, hash, and explorer URL are included for reconciliation when available.

{
  "requests": [
    {
      "id": "cmm5h1a2a001m49h7irxzh22q",
      "status": "review_required",
      "direction": "incoming",
      "amount": 50,
      "currency": "USDC",
      "transaction": null,
      "links": {
        "details": "/api/sdk/a2a/requests/cmm5h1a2a001m49h7irxzh22q",
        "approve": "/api/sdk/a2a/requests/cmm5h1a2a001m49h7irxzh22q/approve",
        "reject": "/api/sdk/a2a/requests/cmm5h1a2a001m49h7irxzh22q/reject",
        "execute": null
      }
    }
  ],
  "total": 1,
  "limit": 50,
  "offset": 0
}

Use the same status values with GET /api/sdk/a2a/requests/{id}.

Webhook-First Automation

If the requested-from agent has a webhook or callback URL configured, Conto also emits payment_request.created as soon as a new request is created. That payload targets the paying agent and includes:

paymentRequestId
requestingAgentId and requestingAgentName
amount, currency, purpose, invoiceId
approveUrl and rejectUrl

Use this path if you want an autonomous agent to react immediately without polling GET /api/sdk/a2a/requests.

Approve or Reject a Request

The paying agent can explicitly approve a pending request before execution:

curl -X POST https://conto.finance/api/sdk/a2a/requests/{id}/approve \
  -H "Authorization: Bearer $CONTO_API_KEY"

The response includes the request ID, approved status, detail URL, and execute URL. Repeating the next step with the returned URLs avoids reconstructing endpoint paths in your integration. To reject it, call the reject endpoint. You can include an optional reason that is stored with the request.

curl -X POST https://conto.finance/api/sdk/a2a/requests/{id}/reject \
  -H "Authorization: Bearer $CONTO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "reason": "This invoice is missing the deployment reference"
  }'

Execute a Request

The receiving agent executes the request:

curl -X POST https://conto.finance/api/sdk/a2a/requests/{id}/execute \
  -H "Authorization: Bearer $CONTO_API_KEY"

The response includes the A2A request ID, transaction ID, customer-facing transaction status, and links to both records. Spend limits, approval rules, counterparty rules, and other policies still apply.

Resolve an Agent from a Wallet Address

curl "https://conto.finance/api/sdk/a2a/resolve?address=0x1234567890abcdef..." \
  -H "Authorization: Bearer $CONTO_API_KEY"

A2A Statistics

GET /api/sdk/a2a/stats

API Reference

Endpoint	Method	Description
`/api/sdk/a2a/request`	POST	Create an A2A payment request
`/api/sdk/a2a/requests`	GET	List A2A requests
`/api/sdk/a2a/requests/{id}`	GET	Get one request
`/api/sdk/a2a/requests/{id}/approve`	POST	Approve a pending request
`/api/sdk/a2a/requests/{id}/reject`	POST	Reject a pending request
`/api/sdk/a2a/requests/{id}/execute`	POST	Execute an approved request
`/api/sdk/a2a/resolve`	POST	Resolve an agent from a wallet address
`/api/sdk/a2a/stats`	GET	View A2A statistics

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A2A Payments

Agent-to-Agent (A2A) Payments

How It Works

Create a Request

List Requests

Webhook-First Automation

Approve or Reject a Request

Execute a Request

Resolve an Agent from a Wallet Address

A2A Statistics

API Reference

​Agent-to-Agent (A2A) Payments

​How It Works

​Create a Request

​List Requests

​Webhook-First Automation

​Approve or Reject a Request

​Execute a Request

​Resolve an Agent from a Wallet Address

​A2A Statistics

​API Reference

Agent-to-Agent (A2A) Payments

How It Works

Create a Request

List Requests

Webhook-First Automation

Approve or Reject a Request

Execute a Request

Resolve an Agent from a Wallet Address

A2A Statistics

API Reference