> ## 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. # Create a volume > Creates a volume you can mount into Sailboxes. Volume names are unique within an organization, so creating a name that already exists returns the existing volume rather than failing. That makes this safe to call on every start. ## OpenAPI ````yaml /sailbox-openapi.json post /sailbox-volumes openapi: 3.1.0 info: title: Sail Sailbox API version: '2026-07-26' description: >- Create and operate Sailboxes over HTTP. Sailboxes are fast-booting virtual machines that you can pause, resume, checkpoint, and fork. Three things need an SDK or the CLI: running commands and moving files, turning on SSH, and building an image. Once SSH is on you can use `ssh` and `scp` for the first of those. 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: Networking description: >- Publish ports, serve them on hostnames you own, and identify a Sailbox to other Sailboxes. - 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: /sailbox-volumes: post: tags: - Volumes summary: Create a volume description: >- Creates a volume you can mount into Sailboxes. Volume names are unique within an organization, so creating a name that already exists returns the existing volume rather than failing. That makes this safe to call on every start. operationId: createVolume parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateVolumeRequest' example: name: shared-datasets responses: '200': description: The volume. content: application/json: schema: $ref: '#/components/schemas/Volume' example: volume_id: vol_4d2e8a11-6c3f-4b95-8e7a-1f0c5d9b3a26 name: shared-datasets backend: nfs status: ready created_at: '2026-07-01T12:00:00Z' updated_at: '2026-07-01T12:00:00Z' headers: Idempotent-Replayed: $ref: '#/components/headers/IdempotentReplayed' '400': 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_gib for size m must be between 8 and 128 type: invalid_request_error param: null code: null headers: Idempotent-Replayed: $ref: '#/components/headers/IdempotentReplayed' '401': description: The API key is missing or invalid. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: Invalid API key type: authentication_error param: null code: invalid_api_key '402': description: >- The organization is out of credits. The error carries a `billing_url` pointing at the page where you add them. Retry once you have. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: >- Your API key has been disabled due to insufficient credits. Visit https://app.sailresearch.com/billing to add credits. type: billing_error param: null code: credits_exhausted billing_url: https://app.sailresearch.com/billing '403': description: The API key is not allowed to perform this operation. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: sailboxes require an organization-scoped API key type: permission_error param: null code: null '409': description: The `Idempotency-Key` was reused for a different request. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: idempotency key reused with a different request body type: conflict_error param: null code: null headers: Idempotent-Replayed: $ref: '#/components/headers/IdempotentReplayed' '413': description: The request body is larger than the 64 KiB this endpoint accepts. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: request body too large type: invalid_request_error param: null code: null '429': description: >- For its first ten minutes a new organization is capped on how many requests it can have in flight at once, and yours is over that cap. The request never started, so retry it unchanged after the delay in the `Retry-After` header. The limit clears as those requests finish. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: >- Too many concurrent requests. Please retry after some of your organization's in-flight requests complete. type: rate_limit_error param: null code: rate_limited headers: Retry-After: $ref: '#/components/headers/RetryAfter' '500': description: Server error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: message: failed to fetch sailbox type: server_error param: null code: null '503': 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' '504': description: >- 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: $ref: '#/components/schemas/ErrorResponse' example: error: message: idempotent request still in flight type: server_error param: null code: null components: parameters: IdempotencyKey: name: Idempotency-Key in: header required: false schema: type: string maxLength: 255 description: >- Makes the request retry-safe. Sail remembers the answer it sent under a key, including a 400 or a 409, and replays it with `Idempotent-Replayed: true` for a retry that repeats the key, the method, the path, and the body. Bodies are compared byte for byte. Reusing a key for a different request returns 409, so send a corrected request under a new key. A key that is blank or only spaces is ignored, and the request runs without idempotency. Any string of up to 255 bytes works, and characters outside ASCII count for more than one. A UUID is a good default. Keys are remembered for at least 24 hours and scoped to the API key that sent them. A server error, or a failure to record the answer, can leave a key unsettled, and creating a Sailbox is where that matters. See [Retrying safely](/sailboxes-http-api#retrying-safely). schemas: CreateVolumeRequest: type: object required: - name properties: name: type: string minLength: 1 maxLength: 128 pattern: ^[A-Za-z0-9._-]+$ description: >- Name for the volume. Letters, numbers, `.`, `-`, and `_` only. Names are unique within your organization. Volume: type: object properties: volume_id: type: string description: Id to pass when mounting the volume. name: type: string description: Name of the volume. backend: type: string description: Storage type of the volume. status: type: string description: >- Current state of the volume: `ready` once it can be mounted, and `deleted` once it has been removed. created_at: type: string format: date-time description: When the volume was created. updated_at: type: string format: date-time description: When the volume last changed. required: - volume_id - name - backend - status 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`, 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. billing_url: type: string format: uri description: Page where you add credits. Sent with a 402. additionalProperties: true headers: IdempotentReplayed: description: >- `true` when this response is the stored answer to an earlier request that sent the same `Idempotency-Key`. Absent when the request ran for the first time. schema: type: string enum: - 'true' 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 ````