> ## Documentation Index > Fetch the complete documentation index at: https://docs.gmicloud.ai/llms.txt > Use this file to discover all available pages before exploring further. # Attach to the sandbox shell (WebSocket) > WebSocket handshake — **not a normal GET**. Code generators produce no usable client for this operation (see `x-websocket`); consumers use a WebSocket library instead. The address is composed from the `POST /shell` response: `wss://{sandbox_key}.{domain}{connect_url}` — the same data-plane host, scheme `wss`. The client sends the standard upgrade headers (`Upgrade: websocket`, `Connection: Upgrade`, plus the `Sec-WebSocket-*` headers WebSocket libraries add automatically) together with the same `X-Access-Token` used by the other data-plane endpoints. When a browser sends an `Origin` header, it must be on the server allowlist, otherwise the handshake is refused with `403`. After the `101` upgrade the connection switches to WebSocket framing: - **BINARY frames only.** client→server frames carry raw terminal input bytes; server→client frames carry raw terminal output bytes (ANSI escape sequences included, xterm.js-compatible). - Text frames are a protocol violation: the server drops the connection. - **No JSON messages in-band.** Resize and close go through `POST /shell/control`, never over the WebSocket. - At most **one active connection per sandbox**; a second concurrent attach is refused at handshake time with `409`. - Disconnecting keeps the shell alive — reattaching resumes the same session. Only `POST /shell/control` with `action=close` destroys it. Pre-upgrade errors are returned as plain HTTP responses (see below). ## OpenAPI ````yaml /api-spec/sandbox_api.yaml get /shell/connect openapi: 3.0.3 info: title: GMI Sandbox API description: >- REST API for GMI Sandbox: create isolated execution environments from templates or durable snapshots, manage their lifecycle on the control plane, and run commands or transfer files through each sandbox's own data plane. contact: name: GMI Cloud Support email: support@gmicloud.ai version: '2.0' servers: - url: https://console.gmicloud.ai/api/v2 description: Control plane security: - bearerAuth: [] tags: - name: Sandbox description: | Sandbox instance lifecycle management (Sandbox v2, /api/v2/sandboxes) - name: SandboxSnapshot description: Durable sandbox snapshot management (Sandbox v2, `/api/v2/snapshots`) - name: SandboxTemplate description: Sandbox template management (Sandbox v2, `/api/v2/templates`) - name: Sandbox-Exec description: > Sandbox execution data plane (accessed via the sandbox host and sandbox access token). These endpoints are not under the control plane's `/api/v2` path; clients connect directly to `https://{sandbox_key}.{domain}` and authenticate with `X-Access-Token`. - name: Sandbox-Shell description: > Sandbox interactive terminal (PTY) data plane. **These endpoints are not under `/api/v2`**: clients connect directly to `https://{sandbox_key}.{domain}` and authenticate with `X-Access-Token`. `{sandbox_key}`, `{domain}` and the `X-Access-Token` value are the `sandbox_key`, `domain` and `sandbox_access_token` returned by the control-plane create/connect endpoints; no extra endpoint is needed. Each sandbox has exactly **one logical shell session** and at most **one active WebSocket connection** at a time (a second concurrent attach is refused at handshake with `409`). Disconnecting does not destroy the shell — re-attaching resumes the same session; only `POST /shell/control` with `action=close` destroys it. - name: Sandbox-Files description: > Sandbox file data plane (`/files`). **These endpoints are not under `/api/v2`** and do not use `Authorization: Bearer`: they are served by the sandbox's own data-plane entry point — clients connect directly to `https://{sandbox_key}.{domain}` and authenticate with `X-Access-Token`. `{sandbox_key}` is the `sandbox_key` returned by the create/connect endpoints, used for data-plane host addressing. `{domain}` and `X-Access-Token` are the `domain` and `sandbox_access_token` from the same responses — no extra endpoint is needed to obtain them. This split is not historical baggage but the nature of a data plane: file transfer is long-lived, high-volume, and addressed per sandbox, differing from the control plane's short requests in both capacity model and failure domain, so they do not share an entry point. **One unified abstraction.** The same contract is served by two backend kinds (an in-sandbox file service / a data-center data-plane proxy); clients need not — and cannot — tell them apart. The cost is that the contract is their intersection: `Content-Length` on download and resumable download (`Range`/`206`) are **optional capabilities** that vary by data center, and clients must work correctly when they are absent. See the per-operation notes below. paths: /shell/connect: get: tags: - Sandbox-Shell summary: Attach to the sandbox shell (WebSocket) description: > WebSocket handshake — **not a normal GET**. Code generators produce no usable client for this operation (see `x-websocket`); consumers use a WebSocket library instead. The address is composed from the `POST /shell` response: `wss://{sandbox_key}.{domain}{connect_url}` — the same data-plane host, scheme `wss`. The client sends the standard upgrade headers (`Upgrade: websocket`, `Connection: Upgrade`, plus the `Sec-WebSocket-*` headers WebSocket libraries add automatically) together with the same `X-Access-Token` used by the other data-plane endpoints. When a browser sends an `Origin` header, it must be on the server allowlist, otherwise the handshake is refused with `403`. After the `101` upgrade the connection switches to WebSocket framing: - **BINARY frames only.** client→server frames carry raw terminal input bytes; server→client frames carry raw terminal output bytes (ANSI escape sequences included, xterm.js-compatible). - Text frames are a protocol violation: the server drops the connection. - **No JSON messages in-band.** Resize and close go through `POST /shell/control`, never over the WebSocket. - At most **one active connection per sandbox**; a second concurrent attach is refused at handshake time with `409`. - Disconnecting keeps the shell alive — reattaching resumes the same session. Only `POST /shell/control` with `action=close` destroys it. Pre-upgrade errors are returned as plain HTTP responses (see below). operationId: attachSandboxShell responses: '101': description: > Handshake succeeded. The connection is now a WebSocket carrying raw terminal bytes in BINARY frames; see the operation description for the framing protocol. If attaching to the shell fails after the upgrade, the server closes the WebSocket with close code `1011` and reason `attach failed`. '400': description: > `Shell.InvalidRequest`: required WebSocket upgrade headers (`Upgrade: websocket`, `Connection: Upgrade`) are missing or malformed. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' '401': $ref: '#/components/responses/SandboxShellUnauthorized' '403': description: > An `Origin` header was present but is not on the server allowlist (browser clients only; non-browser clients normally send no `Origin`). The error code is `Shell.InvalidRequest`. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' '404': $ref: '#/components/responses/SandboxShellNotFound' '409': description: > Attach conflict, one of: - `Shell.AlreadyAttached`: another WebSocket connection is already active (at most one per sandbox). - `Shell.Creating`: a launch is still in progress; retry shortly. - `Shell.Closing`: the shell is being torn down; launch a new one with `POST /shell` afterwards. - `Shell.CreateFailed`: the previous launch failed; launch it again with `POST /shell`. - `Shell.RuntimeNotRunning`: the sandbox is not running. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' example: code: Shell.AlreadyAttached message: shell already has an active connection request_id: req-7f3c '500': description: | `Shell.InternalError`: unexpected server-side failure. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' '503': description: | Temporarily unavailable, one of `Shell.StoreUnavailable` or `Shell.ProviderUnavailable`. Safe to retry. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' security: - sandboxAccessToken: [] servers: - url: https://{sandbox_key}.{domain} description: Sandbox data-plane host variables: sandbox_key: default: sandbox-key description: >- Data-plane addressing key (`sandbox_key` from the control-plane response). domain: default: sandbox.example.com description: Sandbox data-plane domain from the control-plane response. components: schemas: SandboxShellErrorResponse: type: object description: >- Data-plane error body, in the platform error envelope (without `trace_id`). required: - code - message - request_id properties: code: type: string description: >- Machine-readable error code (`Shell.*`; a 401 is always `Auth.Unauthorized`). The set of codes and their meanings are documented on each response. example: Shell.NotFound message: type: string description: Stable, sanitized human-readable error message. request_id: type: string description: >- Server-generated ID for this request (`req-`), identical to the `X-Request-ID` response header. A caller-supplied `X-Request-ID` is not used. example: req-3f2b6c1e-8a0d-4f6b-9c3e-2d7a1b5e9f40 responses: SandboxShellUnauthorized: description: > Missing or invalid `X-Access-Token`, as on the other data-plane endpoints. The body is always `{"code":"Auth.Unauthorized","message":"unauthorized","request_id":"..."}`; missing, malformed, expired, and wrong-sandbox tokens are indistinguishable. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' example: code: Auth.Unauthorized message: unauthorized request_id: req-3f2b6c1e-8a0d-4f6b-9c3e-2d7a1b5e9f40 SandboxShellNotFound: description: | No shell session exists (`Shell.NotFound`): none has been launched yet — call `POST /shell` first — or the shell has already been closed. content: application/json: schema: $ref: '#/components/schemas/SandboxShellErrorResponse' example: code: Shell.NotFound message: no shell session for this sandbox request_id: req-7f3c securitySchemes: bearerAuth: type: http scheme: bearer description: > API Key or Access Token, always sent as `Authorization: Bearer `. The gateway recognizes the token type automatically. sandboxAccessToken: type: apiKey in: header name: X-Access-Token description: > Sandbox data-plane token — the `sandbox_access_token` returned by the create/connect endpoints. Used for `/files`, Sandbox-Exec, and other data-plane endpoints; the control plane (`/api/v2`) does not accept it, and conversely the control plane's `Authorization: Bearer` is invalid on the data plane. The token is bound to its sandbox: using sandbox A's token against sandbox B's host fails. It stays valid until the sandbox's lifetime ends; there is no separate rotation endpoint (`rotate_traffic_token` rotates the port traffic token `traffic_access_token` and does not affect this one). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.