> ## Documentation Index > Fetch the complete documentation index at: https://docs.sailresearch.com/llms.txt > Use this file to discover all available pages before exploring further. # Fetch a file through its download URL > Streams the file a download URL names. Use the URL exactly as minted; its query is signed. The response supports byte ranges, `If-Range`, and the `If-None-Match` and `If-Modified-Since` validators. A fetch wakes a sleeping Sailbox before the first byte. ## OpenAPI ````yaml /sailbox-openapi.json get /sailboxes/{sailbox_id}/files/download openapi: 3.1.0 info: title: Sail Sailbox API version: '2026-09-07' description: >- Create and operate Sailboxes over HTTP. Sailboxes are fast-booting virtual machines that you can pause, resume, and checkpoint. Run commands, stream files, manage lifecycle and networking, and inspect usage. Turning on SSH and building an image still require an SDK or the CLI. See the [HTTP API guide](/sailboxes-http-api). servers: - url: https://sailbox-api.sailresearch.com/v1 security: - BearerAuth: [] tags: - name: Apps description: Groups that own Sailboxes. One app per workload. - name: Lifecycle description: >- A Sailbox's whole life: create it, watch it, stop and start it, terminate it. - name: Checkpoints description: Save a Sailbox to start from later, and copy a running one. - name: Exec description: Run commands and control their standard input and terminals. - name: Files description: Stream regular files into and out of a Sailbox. - name: Networking description: >- Publish ports, serve them on hostnames you own, and identify a Sailbox to other Sailboxes. - name: Secrets description: >- Organization values that egress policy rules can add to matching requests. Sail never returns a stored value. - name: Egress policies description: >- What a Sailbox may connect to, and what happens to the HTTPS requests it sends. - name: Volumes description: >- Shared storage that outlives any one Sailbox. Alpha: these endpoints can still change. - name: SSH access description: Certificates for connecting to a Sailbox with `ssh`. - name: Usage description: Resource usage and spend. - name: Identity description: Who your API key belongs to. paths: /sailboxes/{sailbox_id}/files/download: get: tags: - Files summary: Fetch a file through its download URL description: >- Streams the file a download URL names. Use the URL exactly as minted; its query is signed. The response supports byte ranges, `If-Range`, and the `If-None-Match` and `If-Modified-Since` validators. A fetch wakes a sleeping Sailbox before the first byte. operationId: fetchSailboxFileDownload parameters: - $ref: '#/components/parameters/SailboxId' - name: path in: query required: true schema: type: string description: The file the URL was minted for. - name: expires in: query required: true schema: type: integer format: int64 description: When the URL stops working, as a Unix timestamp in seconds. - name: sig in: query required: true schema: type: string description: >- Signature over the other parameters. Editing any of them invalidates it. - name: disposition in: query required: false schema: type: string enum: - attachment description: Present when the URL was minted with `attachment`. - name: cache in: query required: false schema: type: string enum: - immutable description: Present when the URL was minted with `immutable`. responses: '200': description: >- The whole file. `Content-Type` comes from the file's extension, `Content-Length` is its size, `ETag` and `Last-Modified` are its validators, and `Accept-Ranges: bytes` is set. content: '*/*': schema: type: string format: binary '206': description: The requested byte range, with `Content-Range`. content: '*/*': schema: type: string format: binary '304': description: The file has not changed since the validator the request sent. '400': $ref: '#/components/responses/BadRequest' '403': description: The signature is invalid or the URL has expired. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: download URL has expired type: permission_error param: null code: null '404': description: The Sailbox is terminated or the file does not exist. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: >- read sailbox file: open /workspace/render.png: no such file or directory type: not_found_error param: null code: null '409': description: >- The Sailbox is paused, or the path is a directory or another non-regular file. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: >- sailbox "sb_9c8f1e2a-3b4d-4f5a-8c7e-1d2f3a4b5c6d" is paused. call resume() first type: conflict_error param: null code: null '412': description: '`If-Match` or `If-Unmodified-Since` did not match the file.' '416': description: No part of the requested range lies inside the file. '503': $ref: '#/components/responses/Unavailable' '504': $ref: '#/components/responses/Timeout' security: [] components: parameters: SailboxId: name: sailbox_id in: path required: true schema: type: string description: >- Id of the Sailbox, as returned by create. It is `sb_` followed by a UUID. responses: BadRequest: description: The request was rejected. See the error message for the offending field. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: memory_limit_gib for size m must be between 8 and 128 type: invalid_request_error param: null code: null Unavailable: description: >- Sail is momentarily unavailable. Retry after the delay in the `Retry-After` header when one is present, and with backoff otherwise. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Authentication service unavailable type: server_error param: null code: null headers: Retry-After: $ref: '#/components/headers/RetryAfter' Timeout: description: >- The operation outran its deadline, or a retry sent with the same `Idempotency-Key` waited about 30 seconds and the original request was still going. Retry with the same key. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: idempotent request still in flight type: server_error param: null code: null schemas: ErrorResponse: type: object required: - error properties: error: $ref: '#/components/schemas/ErrorObject' ErrorObject: type: object required: - message - type - param - code properties: message: type: string description: Human-readable description of what went wrong. type: type: string description: >- Error category: `invalid_request_error`, `authentication_error`, `permission_error`, `billing_error`, `not_found_error`, `conflict_error`, `rate_limit_error`, `quota_exceeded_error`, `not_implemented_error`, or `server_error`. param: oneOf: - type: string - type: 'null' description: >- The request field the error refers to, when the error is about one field. code: oneOf: - type: string - type: integer - type: 'null' description: >- Stable short code for the error, when one applies. Errors relayed from the Sailbox runtime carry its status token, for example `already_exists` or `failed_precondition` on a 409, which the HTTP status alone does not distinguish. billing_url: type: string format: uri description: Page where you add credits. Sent with a 402. additionalProperties: true headers: RetryAfter: description: >- How many seconds to wait before retrying. On a 429 it also means the request never started, so the retry can reuse the same `Idempotency-Key`. schema: type: integer minimum: 0 securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: API Key ````