x402-signature-service

Endpoints and prices

Payment evidence

402 payload captured at 2026-07-28 10:20:00 UTC. Check evidence JSON · Measurement methodology.

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xE72b85A97A6e19413D8b80633787Eda6d6237A77",
      "amount": "500000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 120
    }
  ],
  "resource": {
    "url": "https://signx402.com/v1/signature-requests",
    "tags": [
      "signature",
      "e-signature",
      "pdf",
      "documents",
      "contracts",
      "workflow"
    ],
    "mimeType": "application/json",
    "description": "Send one PDF to one email recipient for simple electronic signature. The service emails the signer, tracks completion, and returns the completed signed PDF. Give an AI agent the missing capability to get human sign-off: submit a contract, NDA or agreement by URL or base64, the recipient signs in the browser (powered by Documenso), and the agent polls a status URL with a one-time bearer token until the signed document is ready for download. Simple electronic signatures (SES) only — no QES/AES, no identity verification, no legal advice. Documents are processed in memory; signer emails are masked in logs.",
    "serviceName": "x402-signature-service"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "body": {
            "signer": {
              "name": "Anna Müller",
              "email": "[email protected]"
            },
            "message": "Please review and sign this agreement.",
            "documentUrl": "https://example.com/agreement.pdf",
            "documentName": "Service Agreement",
            "expiresInDays": 14,
            "externalReference": "customer-contract-4821"
          },
          "type": "http",
          "method": "GET",
          "bodyType": "json"
        },
        "output": {
          "type": "json",
          "example": {
            "id": "sigreq_1f4a9c2b7d3e8a01",
            "signer": {
              "name": "Anna Müller",
              "email": "a***@example.com"
            },
            "status": "sent",
            "createdAt": "2026-07-19T15:00:00Z",
            "expiresAt": "2026-08-02T15:00:00Z",
            "statusUrl": "https://your-api.example.com/v1/signature-requests/sigreq_1f4a9c2b7d3e8a01",
            "accessToken": "sec_… (plain-text bearer token, shown exactly once)",
            "documentName": "Service Agreement"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "bodyType",
              "body"
            ],
            "properties": {
              "body": {
                "type": "object",
                "oneOf": [
                  {
                    "not": {
                      "required": [
                        "documentBase64"
                      ]
                    },
                    "required": [
                      "documentUrl"
                    ]
                  },
                  {
                    "not": {
                      "required": [
                        "documentUrl"
                      ]
                    },
                    "required": [
                      "documentBase64"
                    ]
                  }
                ],
                "required": [
                  "documentName",
                  "signer"
                ],
                "properties": {
                  "signer": {
                    "type": "object",
                    "required": [
                      "name",
                      "email"
                    ],
                    "properties": {
                      "name": {
                        "type": "string",
                        "maxLength": 120,
                        "minLength": 1
                      },
                      "email": {
                        "type": "string",
                        "format": "email"
                      }
                    }
                  },
                  "message": {
                    "type": "string",
                    "maxLength": 2000,
                    "description": "Optional message included in the signature request email"
                  },
                  "documentUrl": {
                    "type": "string",
                    "description": "HTTPS URL of the PDF to sign (max 5 MB). Provide either documentUrl OR documentBase64."
                  },
                  "documentName": {
                    "type": "string",
                    "maxLength": 150,
                    "minLength": 1,
                    "description": "Human-readable document title shown to the signer"
                  },
                  "expiresInDays": {
                    "type": "integer",
                    "default": 14,
                    "maximum": 30,
                    "minimum": 1,
                    "description": "Days until the signature request expires"
                  },
                  "documentBase64": {
                    "type": "string",
                    "description": "Base64-encoded PDF (max 5 MB decoded). Provide either documentUrl OR documentBase64."
                  },
                  "externalReference": {
                    "type": "string",
                    "maxLength": 200,
                    "description": "Optional caller-side reference id, echoed back in responses"
                  }
                }
              },
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "POST",
                  "PUT",
                  "PATCH"
                ],
                "type": "string"
              },
              "bodyType": {
                "enum": [
                  "json",
                  "form-data",
                  "text"
                ],
                "type": "string"
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "required": [
                  "id",
                  "status",
                  "statusUrl",
                  "accessToken"
                ],
                "properties": {
                  "id": {
                    "type": "string"
                  },
                  "signer": {
                    "type": "object",
                    "properties": {
                      "name": {
                        "type": "string"
                      },
                      "email": {
                        "type": "string",
                        "description": "masked, e.g. a***@example.com"
                      }
                    }
                  },
                  "status": {
                    "enum": [
                      "sent",
                      "viewed",
                      "completed",
                      "declined",
                      "expired",
                      "error"
                    ],
                    "type": "string"
                  },
                  "createdAt": {
                    "type": "string"
                  },
                  "expiresAt": {
                    "type": "string"
                  },
                  "statusUrl": {
                    "type": "string",
                    "description": "Poll this URL with 'Authorization: Bearer <accessToken>' to track progress; append /document once completed to download the signed PDF."
                  },
                  "accessToken": {
                    "type": "string",
                    "description": "One-time plain-text bearer token for statusUrl and document download. Store it — it is never shown again."
                  },
                  "documentName": {
                    "type": "string"
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}