> ## Documentation Index > Fetch the complete documentation index at: https://docs.phoneuse.com/llms.txt > Use this file to discover all available pages before exploring further. # Fetch a frame > Returns raw image bytes, not JSON and not base64. A frame is metered BEFORE the pixels are returned. If the metering write fails, the frame is withheld and the request fails: the path that could hand out an uncounted frame is the path that must not exist. The implication runs one way only, and it is stated rather than hidden: a frame that was delivered was counted, but a frame that was counted may not have been delivered, because a client can disconnect between the two. Running out of budget refuses the frame; it does not end the run. A worker that takes one last look before reporting success should not have that success turned into a failure. A frame is also refused, with the same 409, while the run is parked for a person (`needs_user_control`) or on hold (`paused`): the device is not observed by the worker while a person has stopped it, so a worker should wait and retry, not report failure. A person may drive the same device beside this run without stopping it. What they did since this run's previous frame rides in three response headers, so a worker can look again before it decides: `X-Phonebase-Others-Actions`, `X-Phonebase-Others-Last-At` (absent when the count is 0) and `X-Phonebase-Others-By` (absent when the count is 0; otherwise `person`, `agent` or both, comma separated). The driver this surface exists for reads no headers and loses nothing. This operation reads no `Authorization` header. The run token in the path IS the credential, so the whole url is secret: never log it, paste it, or commit it. Every example writes `{runToken}` for that reason. ## OpenAPI ````yaml /api/openapi.json get /vrx/{runToken}/v1/devices/{deviceId}/screenshot openapi: 3.1.0 info: title: Phonebase HTTP API version: 0.1.0 summary: >- Every HTTP operation the control plane mounts, generated from the app's own route table. description: >- The control plane exposes two HTTP surfaces, and reading the boundary between them matters more than reading any single endpoint. The CONTROL surface is what your backend and your operators call. It takes a bearer token in the `Authorization` header, and two credential channels resolve to the same authorization context: an OAuth 2.1 access token for interactive clients, or an org scoped API key for headless ones. The DEVICE surface, under `/vrx/{runToken}/v1`, is what a worker calls while executing one run. Its credential is the run token in the url path, and it reads no `Authorization` header at all. Device control itself is not REST. An agent taps, swipes and reads the screen over the Model Context Protocol at `POST /mcp`, one tool call at a time. There is no `POST /v1/devices/{id}/tap`, and if you are looking for one, start with the tool reference instead. Operations marked `"x-phonebase-modes": ["hosted"]` exist only on a hosted deployment; a local checkout does not mount them. servers: - url: '{origin}' description: Your control plane origin. variables: origin: default: https://mcp.phonebase.co enum: - https://mcp.phonebase.co - http://127.0.0.1:8788 description: >- The hosted deployment serves the public origin its metadata document advertises, and that is the default here. Select the loopback entry instead when you are running a local checkout, which serves the port `PORT` names. security: [] tags: - name: Apps description: Save immutable application builds and manage explicit device operations. - name: Managed Proxy description: >- Organization-owned fixed egress resources, independent one-time orders and verified network relationships. - name: Health description: Liveness, unauthenticated. - name: Gateway enrollment description: >- How a new gateway computer trades a one-time enrollment code for its tunnel credential. Unauthenticated: the code is the credential. - name: Gateway releases description: >- What a gateway computer installs: the current edge release of a channel. Called with the gateway's own credential. - name: MCP description: The JSON-RPC endpoint an agent drives devices through. - name: Copilot description: >- Drive a device by chatting. A signed in person's own conversations, streamed. Hosted deployments only. - name: Discovery description: Where to authenticate. Served on hosted deployments only. - name: Runs description: Start, watch and steer a run. - name: API keys description: Mint and revoke headless credentials. Hosted deployments only. - name: Device surface description: What a worker calls with its run token to observe and act. - name: Usage description: Read your org's own receipts and consumption. Hosted deployments only. - name: Devices description: Read the fleet your credential can see. Hosted deployments only. - name: Notifications description: >- What a person needs to know when they are not watching, and which emails they receive. Hosted deployments only. - name: Webhooks description: >- Subscribe your own system to what happens here, and read what was delivered. Hosted deployments only. - name: Provisioning description: >- Whether an organisation is provisioned, and how it becomes so. Hosted deployments only, and both operations answer a declared 503 on a deployment that cannot provision yet. paths: /vrx/{runToken}/v1/devices/{deviceId}/screenshot: get: tags: - Device surface summary: Fetch a frame description: >- Returns raw image bytes, not JSON and not base64. A frame is metered BEFORE the pixels are returned. If the metering write fails, the frame is withheld and the request fails: the path that could hand out an uncounted frame is the path that must not exist. The implication runs one way only, and it is stated rather than hidden: a frame that was delivered was counted, but a frame that was counted may not have been delivered, because a client can disconnect between the two. Running out of budget refuses the frame; it does not end the run. A worker that takes one last look before reporting success should not have that success turned into a failure. A frame is also refused, with the same 409, while the run is parked for a person (`needs_user_control`) or on hold (`paused`): the device is not observed by the worker while a person has stopped it, so a worker should wait and retry, not report failure. A person may drive the same device beside this run without stopping it. What they did since this run's previous frame rides in three response headers, so a worker can look again before it decides: `X-Phonebase-Others-Actions`, `X-Phonebase-Others-Last-At` (absent when the count is 0) and `X-Phonebase-Others-By` (absent when the count is 0; otherwise `person`, `agent` or both, comma separated). The driver this surface exists for reads no headers and loses nothing. This operation reads no `Authorization` header. The run token in the path IS the credential, so the whole url is secret: never log it, paste it, or commit it. Every example writes `{runToken}` for that reason. operationId: getVrxByRunTokenV1DevicesByDeviceIdScreenshot parameters: - name: runToken in: path required: true description: The run token. Write `{runToken}`; never write a real one down. schema: type: string - name: deviceId in: path required: true description: >- Must be the device this run is bound to. Anything else is refused as not found. schema: type: string responses: '200': description: The frame, as image bytes. The media type says which encoding. headers: X-Phonebase-Others-Actions: description: >- How many actions principals other than this run took on the device since the run's previous frame (or in the last sixty seconds, for a first frame). Pending and committed receipts count. schema: type: string X-Phonebase-Others-Last-At: description: >- When the newest of them was requested, ISO 8601 on the control plane's clock. Absent when the count is 0. schema: type: string X-Phonebase-Others-By: description: >- `person`, `agent`, or `person,agent`: who they were. Absent when the count is 0. schema: type: string content: image/png: {} image/jpeg: {} '404': description: >- Unknown, expired, terminal, or addressed at a device this run does not own. All four answer identically, so holding a token tells you nothing about which it was. If you reached this with an org API key rather than a run token, the code is misleading and the message says so: nothing is missing, this is the worker channel and your credential does not apply to it. Drive devices yourself over the MCP endpoint instead. content: application/json: schema: $ref: '#/components/schemas/DeviceError' '409': description: >- The frame was refused: either the run has no further steps (its budget or deadline is spent) or the run is parked for a person and not currently driving the device. Both cases leave the run alive. content: application/json: schema: $ref: '#/components/schemas/DeviceError' '429': description: >- Over the request budget for this caller. Hosted deployments only. Which budget applied depends on whether this request carried an `Authorization` header, not on which endpoint it was aimed at. Wait `Retry-After` seconds and retry the same request: the refusal happens before any work, so nothing was partially applied. See /api/rate-limits. headers: Retry-After: description: >- Whole seconds until one request is available again. Computed from the caller's own remaining allowance, not a fixed constant. schema: type: string RateLimit-Limit: description: >- The budget in effect for this caller class, in requests per minute. schema: type: string RateLimit-Remaining: description: >- Whole requests that were still available when this request was admitted. Zero on a 429. schema: type: string RateLimit-Reset: description: >- Seconds until the allowance is back to full. Longer than `Retry-After`, which is the wait for a single request. schema: type: string RateLimit-Policy: description: The budget and its window, as `;w=60`. schema: type: string content: application/json: schema: $ref: '#/components/schemas/RateLimitedError' '503': description: >- The device is not reachable, the frame carries no identity, or metering was unavailable. content: application/json: schema: $ref: '#/components/schemas/DeviceError' security: [] components: schemas: DeviceError: type: object properties: ok: type: boolean const: false error: type: object properties: code: type: string enum: - DEVICE_NOT_FOUND - INVALID_ACTION - FRAME_VIEWPORT_MISMATCH - COORDINATE_OUT_OF_REACH - ACTION_UNAVAILABLE - FENCING_TOKEN_STALE - STALE_FRAME - HARDWARE_OFFLINE - FRAME_UNAVAILABLE - ACTION_OUTCOME_UNKNOWN description: The dialect code to branch on. message: type: string description: >- A constant summary per branch. Internal error text is never forwarded here. details: type: object description: >- Structured detail for the branches that have any (spec §8, §15.4). `STALE_FRAME` carries `reason` (`unknown_frame`, `superseded`, `expired`, `viewport_changed`, `others_acted`; read anything else as `unknown_frame`), and an `ACTION_UNAVAILABLE` raised by a full device queue carries `retryAfterMs`. Absent on every other branch, and it never carries internal text. additionalProperties: true required: - code - message additionalProperties: false required: - ok - error additionalProperties: false description: >- The device surface answers in the dialect's own error shape, not the control surface envelope. RateLimitedError: type: object properties: error: type: object properties: code: type: string const: rate_limited description: Always `rate_limited` on this response. message: type: string description: >- A human readable summary. The numbers are in the headers, not in here. required: - code - message additionalProperties: false required: - error additionalProperties: false description: >- Over the request budget. Raised by the rate limiter before any handler runs, which is why its code is not one of the action codes: nothing was attempted, so no action failed. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.