All workflows

Tool Contract Bridge

Compare a required JSON input contract with candidate tool schemas and identify compatible tools, missing fields, extra required inputs and type conflicts before delegation.

2 credits per call · $0.02 USDC with x402

Sample input

{
  "required_schema": {
    "type": "object",
    "required": [
      "url"
    ],
    "properties": {
      "url": {
        "type": "string"
      }
    }
  },
  "candidates": [
    {
      "id": "reader",
      "input_schema": {
        "type": "object",
        "required": [
          "url"
        ],
        "properties": {
          "url": {
            "type": "string"
          }
        }
      }
    },
    {
      "id": "other",
      "input_schema": {
        "type": "object",
        "required": [
          "query"
        ],
        "properties": {
          "query": {
            "type": "string"
          }
        }
      }
    }
  ]
}

Worked sample output

{
  "ok": true,
  "mode": "tool_contract_bridge",
  "candidates": [
    {
      "id": "reader",
      "compatible": true,
      "issue_count": 0,
      "issues": [],
      "candidate_property_count": 1,
      "extra_required_fields": []
    },
    {
      "id": "other",
      "compatible": false,
      "issue_count": 2,
      "issues": [
        {
          "path": "/url",
          "code": "missing_candidate_property"
        },
        {
          "path": "/query",
          "code": "candidate_requires_extra_field"
        }
      ],
      "candidate_property_count": 1,
      "extra_required_fields": [
        "query"
      ]
    }
  ],
  "compatible_candidates": [
    "reader"
  ],
  "limitations": [
    "Checks a conservative supported JSON Schema subset and required-field compatibility. It does not prove semantic equivalence between tools."
  ]
}

Worked example using published sample data only. Own-data execution is paid.

Connect in curl

Set BOUNTY_API_KEY privately after your payment is verified. Change the retry key for each new logical request.

curl 'https://bounty-engineer-x402-prod.onrender.com/v1/prepaid/tool-contract-bridge' \
  -H "Authorization: Bearer $BOUNTY_API_KEY" \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: workflow-request-001' \
  -H 'X-Max-Credits: 2' \
  --data '{"required_schema":{"type":"object","required":["url"],"properties":{"url":{"type":"string"}}},"candidates":[{"id":"reader","input_schema":{"type":"object","required":["url"],"properties":{"url":{"type":"string"}}}},{"id":"other","input_schema":{"type":"object","required":["query"],"properties":{"query":{"type":"string"}}}}]}'

Connect in n8n

Download the inactive n8n template. Import it, configure the private Header Auth credential, inspect the sample and run it manually. A new execution creates a new billable request; there is no automatic schedule.

Use an HTTP POST to https://bounty-engineer-x402-prod.onrender.com/v1/prepaid/tool-contract-bridge. Send JSON and these headers; store the Bearer token as a private credential.

{
  "method": "POST",
  "headers": {
    "Authorization": "Bearer YOUR_PRIVATE_API_KEY",
    "Content-Type": "application/json",
    "Idempotency-Key": "UNIQUE_PER_LOGICAL_REQUEST",
    "X-Max-Credits": "2"
  },
  "body": {
    "required_schema": {
      "type": "object",
      "required": [
        "url"
      ],
      "properties": {
        "url": {
          "type": "string"
        }
      }
    },
    "candidates": [
      {
        "id": "reader",
        "input_schema": {
          "type": "object",
          "required": [
            "url"
          ],
          "properties": {
            "url": {
              "type": "string"
            }
          }
        }
      },
      {
        "id": "other",
        "input_schema": {
          "type": "object",
          "required": [
            "query"
          ],
          "properties": {
            "query": {
              "type": "string"
            }
          }
        }
      }
    ]
  }
}

Reuse a retry key only for the same input. Failed execution returns reserved credits. Full integration and recovery guide · Machine-readable recipe