Bind a guest payment checkout handoff

Private access capability and receiver-bound one-use handoff proposal. Save the random handoff before submission so a lost response can repeat the same proposal.

accessIdRequired

Noncredential payment access UUID issued for the native source.

string · uuid

Full definition

{
  "type": "string",
  "format": "uuid",
  "description": "Noncredential payment access UUID issued for the native source.",
  "example": "b93bc84d-84db-4161-840b-c3c7a7875b1d"
}

capabilityRequired

Current private payment-access capability, presented only in this body.

string

Full definition

{
  "type": "string",
  "minLength": 48,
  "maxLength": 48,
  "pattern": "^gpa1_[A-Za-z0-9_-]{43}$",
  "example": "gpa1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
  "writeOnly": true,
  "description": "Current private payment-access capability, presented only in this body."
}

handoffRequired

Client-generated 32-byte canonical base64url handoff with the gph1_ prefix. Generate with cryptographic randomness and save privately before this call.

string

Full definition

{
  "type": "string",
  "minLength": 48,
  "maxLength": 48,
  "pattern": "^gph1_[A-Za-z0-9_-]{43}$",
  "example": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
  "writeOnly": true,
  "description": "Client-generated 32-byte canonical base64url handoff with the gph1_ prefix. Generate with cryptographic randomness and save privately before this call."
}

recipientCapabilityHashRequired

SHA-256 hex digest of the complete fresh gpa1_ capability already chosen and privately saved by the receiving checkout context. The raw receiver capability is not sent to the opener.

string

Full definition

{
  "type": "string",
  "minLength": 64,
  "maxLength": 64,
  "pattern": "^[a-f0-9]{64}$",
  "writeOnly": true,
  "description": "SHA-256 hex digest of the complete fresh gpa1_ capability already chosen and privately saved by the receiving checkout context. The raw receiver capability is not sent to the opener.",
  "example": "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
}

{
  "type": "object",
  "properties": {
    "accessId": {
      "type": "string",
      "format": "uuid",
      "description": "Noncredential payment access UUID issued for the native source.",
      "example": "b93bc84d-84db-4161-840b-c3c7a7875b1d"
    },
    "capability": {
      "type": "string",
      "minLength": 48,
      "maxLength": 48,
      "pattern": "^gpa1_[A-Za-z0-9_-]{43}$",
      "example": "gpa1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
      "writeOnly": true,
      "description": "Current private payment-access capability, presented only in this body."
    },
    "handoff": {
      "type": "string",
      "minLength": 48,
      "maxLength": 48,
      "pattern": "^gph1_[A-Za-z0-9_-]{43}$",
      "example": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
      "writeOnly": true,
      "description": "Client-generated 32-byte canonical base64url handoff with the gph1_ prefix. Generate with cryptographic randomness and save privately before this call."
    },
    "recipientCapabilityHash": {
      "type": "string",
      "minLength": 64,
      "maxLength": 64,
      "pattern": "^[a-f0-9]{64}$",
      "writeOnly": true,
      "description": "SHA-256 hex digest of the complete fresh gpa1_ capability already chosen and privately saved by the receiving checkout context. The raw receiver capability is not sent to the opener.",
      "example": "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
    }
  },
  "description": "Private access capability and receiver-bound one-use handoff proposal. Save the random handoff before submission so a lost response can repeat the same proposal.",
  "required": [
    "accessId",
    "capability",
    "handoff",
    "recipientCapabilityHash"
  ],
  "example": {
    "accessId": "b93bc84d-84db-4161-840b-c3c7a7875b1d",
    "capability": "gpa1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
    "handoff": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
    "recipientCapabilityHash": "deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
  }
}

Private one-use handoff acknowledgement bound to one receiving capability digest and the configured top-level checkout origin.

accessIdRequired

Noncredential access context UUID used to match the receiver and handshake.

string · uuid

Full definition

{
  "type": "string",
  "format": "uuid",
  "description": "Noncredential access context UUID used to match the receiver and handshake.",
  "example": "b93bc84d-84db-4161-840b-c3c7a7875b1d"
}

handoffRequired

The exact caller-saved private handoff. Transfer only to the validated checkout receiver or a private POST-body bridge.

string

Full definition

{
  "type": "string",
  "minLength": 48,
  "maxLength": 48,
  "pattern": "^gph1_[A-Za-z0-9_-]{43}$",
  "example": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
  "description": "The exact caller-saved private handoff. Transfer only to the validated checkout receiver or a private POST-body bridge."
}

expiresAtRequired

Initial redemption deadline, at most sixty seconds and within the access/native deadlines. Successful repeats recover the same redeemed audience without extending access.

string · date-time

Full definition

{
  "type": "string",
  "format": "date-time",
  "description": "Initial redemption deadline, at most sixty seconds and within the access/native deadlines. Successful repeats recover the same redeemed audience without extending access.",
  "example": "2026-12-31T18:00:00.000Z"
}

destinationOriginRequired

Configured trusted checkout origin. postMessage must use this exact targetOrigin with the expected window and access context; never use a wildcard or transfer to a parent frame.

string · uri

Full definition

{
  "type": "string",
  "format": "uri",
  "description": "Configured trusted checkout origin. postMessage must use this exact targetOrigin with the expected window and access context; never use a wildcard or transfer to a parent frame.",
  "example": "https://example.test/resource"
}

{
  "type": "object",
  "properties": {
    "accessId": {
      "type": "string",
      "format": "uuid",
      "description": "Noncredential access context UUID used to match the receiver and handshake.",
      "example": "b93bc84d-84db-4161-840b-c3c7a7875b1d"
    },
    "handoff": {
      "type": "string",
      "minLength": 48,
      "maxLength": 48,
      "pattern": "^gph1_[A-Za-z0-9_-]{43}$",
      "example": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
      "description": "The exact caller-saved private handoff. Transfer only to the validated checkout receiver or a private POST-body bridge."
    },
    "expiresAt": {
      "type": "string",
      "format": "date-time",
      "description": "Initial redemption deadline, at most sixty seconds and within the access/native deadlines. Successful repeats recover the same redeemed audience without extending access.",
      "example": "2026-12-31T18:00:00.000Z"
    },
    "destinationOrigin": {
      "type": "string",
      "format": "uri",
      "description": "Configured trusted checkout origin. postMessage must use this exact targetOrigin with the expected window and access context; never use a wildcard or transfer to a parent frame.",
      "example": "https://example.test/resource"
    }
  },
  "description": "Private one-use handoff acknowledgement bound to one receiving capability digest and the configured top-level checkout origin.",
  "required": [
    "accessId",
    "handoff",
    "expiresAt",
    "destinationOrigin"
  ],
  "example": {
    "accessId": "b93bc84d-84db-4161-840b-c3c7a7875b1d",
    "handoff": "gph1_AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
    "expiresAt": "2026-12-31T18:00:00.000Z",
    "destinationOrigin": "https://example.test/resource"
  }
}

Stable error envelope emitted by the global HTTP exception boundary. Domain-specific machine data, when present, is nested under details.

statusCodeRequired

HTTP status code repeated from the response.

integer

Full definition

{
  "type": "integer",
  "description": "HTTP status code repeated from the response.",
  "example": 400
}

errorRequired

Translation key for the HTTP category, such as errors:http.conflict. The specific cause is identified by code and translationKey.

string

Full definition

{
  "type": "string",
  "description": "Translation key for the HTTP category, such as errors:http.conflict. The specific cause is identified by code and translationKey.",
  "example": "errors.request.invalid"
}

codeRequired

Stable machine-readable domain code, or an HTTP_* fallback when no domain code is provided. Branch on this field and the HTTP status; localized wording never controls retries or business decisions.

string

Full definition

{
  "type": "string",
  "example": "HTTP_BAD_REQUEST",
  "description": "Stable machine-readable domain code, or an HTTP_* fallback when no domain code is provided. Branch on this field and the HTTP status; localized wording never controls retries or business decisions."
}

messageRequired

Translation key, identical to translationKey. The API does not return localized display text. Resolve the key and translationValues in the consuming application.

string

Full definition

{
  "type": "string",
  "example": "errors:http.badRequest",
  "description": "Translation key, identical to translationKey. The API does not return localized display text. Resolve the key and translationValues in the consuming application."
}

translationKeyRequired

Canonical translation key, identical to message. Status-specific errors:http.* keys cover unspecified failures. Public keys and EN/RU explanations are listed in Developers; unknown keys require a localized client fallback.

string

Full definition

{
  "type": "string",
  "example": "errors:http.badRequest",
  "description": "Canonical translation key, identical to message. Status-specific errors:http.* keys cover unspecified failures. Public keys and EN/RU explanations are listed in Developers; unknown keys require a localized client fallback."
}

translationValuesOptional

Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.

object

Full definition

{
  "type": "object",
  "additionalProperties": {
    "oneOf": [
      {
        "type": "string",
        "example": "example"
      },
      {
        "type": "number",
        "example": 0
      },
      {
        "type": "boolean",
        "example": true
      }
    ],
    "example": "example"
  },
  "description": "Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.",
  "example": {
    "exampleKey": "example"
  }
}

validationErrorsOptional

Field validation failures with translation keys and stable validator codes. Submitted values and raw validator text are not included.

array

Full definition

{
  "description": "Field validation failures with translation keys and stable validator codes. Submitted values and raw validator text are not included.",
  "type": "array",
  "items": {
    "$ref": "#/components/schemas/ValidationErrorDto"
  },
  "example": [
    {
      "field": "email",
      "translationKey": "validation:isEmail",
      "code": "isEmail",
      "message": "validation:isEmail"
    }
  ]
}

detailsOptional

Optional domain-specific blocker or validation details

oneOf

Full definition

{
  "description": "Optional domain-specific blocker or validation details",
  "oneOf": [
    {
      "type": "array",
      "items": {
        "$ref": "#/components/schemas/JsonValue"
      },
      "example": [
        "example"
      ]
    },
    {
      "type": "object",
      "additionalProperties": {
        "$ref": "#/components/schemas/JsonValue"
      },
      "example": {
        "exampleKey": "example"
      }
    }
  ],
  "example": [
    "example"
  ]
}

{
  "type": "object",
  "properties": {
    "statusCode": {
      "type": "integer",
      "description": "HTTP status code repeated from the response.",
      "example": 400
    },
    "error": {
      "type": "string",
      "description": "Translation key for the HTTP category, such as errors:http.conflict. The specific cause is identified by code and translationKey.",
      "example": "errors.request.invalid"
    },
    "code": {
      "type": "string",
      "example": "HTTP_BAD_REQUEST",
      "description": "Stable machine-readable domain code, or an HTTP_* fallback when no domain code is provided. Branch on this field and the HTTP status; localized wording never controls retries or business decisions."
    },
    "message": {
      "type": "string",
      "example": "errors:http.badRequest",
      "description": "Translation key, identical to translationKey. The API does not return localized display text. Resolve the key and translationValues in the consuming application."
    },
    "translationKey": {
      "type": "string",
      "example": "errors:http.badRequest",
      "description": "Canonical translation key, identical to message. Status-specific errors:http.* keys cover unspecified failures. Public keys and EN/RU explanations are listed in Developers; unknown keys require a localized client fallback."
    },
    "translationValues": {
      "type": "object",
      "additionalProperties": {
        "oneOf": [
          {
            "type": "string",
            "example": "example"
          },
          {
            "type": "number",
            "example": 0
          },
          {
            "type": "boolean",
            "example": true
          }
        ],
        "example": "example"
      },
      "description": "Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.",
      "example": {
        "exampleKey": "example"
      }
    },
    "validationErrors": {
      "description": "Field validation failures with translation keys and stable validator codes. Submitted values and raw validator text are not included.",
      "type": "array",
      "items": {
        "$ref": "#/components/schemas/ValidationErrorDto"
      },
      "example": [
        {
          "field": "email",
          "translationKey": "validation:isEmail",
          "code": "isEmail",
          "message": "validation:isEmail"
        }
      ]
    },
    "details": {
      "description": "Optional domain-specific blocker or validation details",
      "oneOf": [
        {
          "type": "array",
          "items": {
            "$ref": "#/components/schemas/JsonValue"
          },
          "example": [
            "example"
          ]
        },
        {
          "type": "object",
          "additionalProperties": {
            "$ref": "#/components/schemas/JsonValue"
          },
          "example": {
            "exampleKey": "example"
          }
        }
      ],
      "example": [
        "example"
      ]
    }
  },
  "required": [
    "statusCode",
    "error",
    "code",
    "message",
    "translationKey"
  ],
  "description": "Stable error envelope emitted by the global HTTP exception boundary. Domain-specific machine data, when present, is nested under details.",
  "example": {
    "statusCode": 400,
    "error": "errors:http.badRequest",
    "code": "HTTP_BAD_REQUEST",
    "message": "errors:http.badRequest",
    "translationKey": "errors:http.badRequest"
  }
}

Field validation failure with a field path, stable validator code and a translation key. Human-readable text belongs to the consuming application.

fieldRequired

Public field path. Nested properties and array indices are separated by dots.

string

Full definition

{
  "type": "string",
  "example": "email",
  "description": "Public field path. Nested properties and array indices are separated by dots."
}

translationKeyRequired

Translation key for this validator, identical to message. Resolve it using a client dictionary; see the public Developers error catalog.

string

Full definition

{
  "type": "string",
  "example": "validation:isEmail",
  "description": "Translation key for this validator, identical to message. Resolve it using a client dictionary; see the public Developers error catalog."
}

codeRequired

Stable validator identifier for this field failure. Custom validators may define additional identifiers.

string

Full definition

{
  "type": "string",
  "example": "isEmail",
  "description": "Stable validator identifier for this field failure. Custom validators may define additional identifiers."
}

messageRequired

Translation key describing this field validation failure, identical to translationKey. Submitted values and validator prose are not included.

string

Full definition

{
  "type": "string",
  "example": "validation:isEmail",
  "description": "Translation key describing this field validation failure, identical to translationKey. Submitted values and validator prose are not included."
}

translationValuesOptional

Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.

object

Full definition

{
  "type": "object",
  "additionalProperties": {
    "oneOf": [
      {
        "type": "string",
        "example": "example"
      },
      {
        "type": "number",
        "example": 0
      },
      {
        "type": "boolean",
        "example": true
      }
    ],
    "example": "example"
  },
  "description": "Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.",
  "example": {
    "exampleKey": "example"
  }
}

{
  "type": "object",
  "properties": {
    "field": {
      "type": "string",
      "example": "email",
      "description": "Public field path. Nested properties and array indices are separated by dots."
    },
    "translationKey": {
      "type": "string",
      "example": "validation:isEmail",
      "description": "Translation key for this validator, identical to message. Resolve it using a client dictionary; see the public Developers error catalog."
    },
    "code": {
      "type": "string",
      "example": "isEmail",
      "description": "Stable validator identifier for this field failure. Custom validators may define additional identifiers."
    },
    "message": {
      "type": "string",
      "example": "validation:isEmail",
      "description": "Translation key describing this field validation failure, identical to translationKey. Submitted values and validator prose are not included."
    },
    "translationValues": {
      "type": "object",
      "additionalProperties": {
        "oneOf": [
          {
            "type": "string",
            "example": "example"
          },
          {
            "type": "number",
            "example": 0
          },
          {
            "type": "boolean",
            "example": true
          }
        ],
        "example": "example"
      },
      "description": "Optional scalar values for placeholders in the translation. Treat values as data, escape them when rendering, and never use them as translation options.",
      "example": {
        "exampleKey": "example"
      }
    }
  },
  "required": [
    "field",
    "translationKey",
    "code",
    "message"
  ],
  "description": "Field validation failure with a field path, stable validator code and a translation key. Human-readable text belongs to the consuming application.",
  "example": {
    "field": "email",
    "translationKey": "validation:isEmail",
    "code": "isEmail",
    "message": "validation:isEmail"
  }
}

Recursively JSON-safe value used only where the owning contract intentionally allows free-form structured data.

{
  "oneOf": [
    {
      "type": "string",
      "nullable": true,
      "example": "example"
    },
    {
      "type": "number",
      "example": 0
    },
    {
      "type": "boolean",
      "example": true
    },
    {
      "type": "array",
      "items": {
        "$ref": "#/components/schemas/JsonValue"
      },
      "example": [
        "example"
      ]
    },
    {
      "type": "object",
      "additionalProperties": {
        "$ref": "#/components/schemas/JsonValue"
      },
      "example": {
        "exampleKey": "example"
      }
    }
  ],
  "description": "Recursively JSON-safe value used only where the owning contract intentionally allows free-form structured data.",
  "example": "example"
}