Build a paywall

{  "id": "pw_build_k3v8n1q6x2c9m4h7d5b0w8e2",  "paywallId": "pw_h7d2k9m4x1c6v8b3n5q0w2e7",  "number": 3,  "status": "building",  "documentVersion": 41,  "isDeployed": false,  "deployedAt": null,  "flowPackage": null,  "failure": null,  "createdByUserId": "user_k3m8q1z6v9c2x5b7n4w0e8r1",  "createdAt": "2026-03-10T11:03:30.000Z",  "finishedAt": null}

{  "error": {    "type": "invalid_request",    "code": "invalid_body",    "message": "The request body is invalid: Expected object"  }}

{  "error": {    "type": "unauthenticated",    "code": "invalid_api_key",    "message": "This secret key is not valid."  }}

{  "error": {    "type": "permission_denied",    "code": "person_credential_required",    "message": "Only a person can do this; project secret keys cannot."  }}

{  "error": {    "type": "not_found",    "code": "project_not_found",    "message": "There is no project proj_tz4a98xxat96iws9zmbrgj3a, or this credential cannot use it.",    "param": "projectId"  }}

{  "error": {    "type": "conflict",    "code": "paywall_document_changed",    "message": "The paywall changed after version 12; it is at version 14 now. Review it and build that version.",    "param": "documentVersion"  }}

{  "error": {    "type": "internal",    "code": "internal_error",    "message": "Something went wrong on our side. Try again, and contact support with the Request-Id header if it keeps failing."  }}