Download a build artifact

OpenAPI contract

Method

GET

Path

/api/v1/builds/{taskId}/download

Security

jwtBearer (bearer) OR automationKey (bearer)

Response status

200 400 401 403 404 429 500

Request and response schemas

JSON

{
  "requestBody": {},
  "responses": {
    "200": {
      "description": "Build artifact",
      "content": {
        "application/octet-stream": {
          "format": "binary",
          "type": "string"
        }
      }
    },
    "400": {
      "description": "Invalid request",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/RequestError"
        }
      }
    },
    "401": {
      "description": "Authentication required or invalid",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/SecurityError"
        }
      }
    },
    "403": {
      "description": "Authenticated but not permitted",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/SecurityError"
        }
      }
    },
    "404": {
      "description": "Requested build was not found",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/ApiError"
        }
      }
    },
    "429": {
      "description": "HTTP rate limit or API-key NCU usage limit exceeded",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/RateLimitError"
        }
      }
    },
    "500": {
      "description": "Unexpected server error",
      "content": {
        "application/json": {
          "$ref": "#/components/schemas/ApiError"
        }
      }
    }
  }
}

Download a private build output with a JWT or an nfy_ key carrying artifact:read; build:read alone is not enough. The service also authorizes the exact task before supplying a compiled-output filename as an attachment. A project task requires effective artifact:output:read; a legacy or ad-hoc task uses its exact-owner fallback.

The artifact is unavailable until output exists, and it can disappear after retention cleanup or task deletion. A missing or unauthorized task, an unfinished build, or already-cleaned storage does not yield a usable file. Save a release copy outside the service before the entitlement-based retention period ends.