> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mobilerun.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Execute JavaScript in the device's Chrome browser (CDP)

> Evaluates a JavaScript expression in the device's foreground Chrome tab via the Chrome DevTools Protocol and returns its JSON-serialized result. Devices without browser support return an unsupported-feature error.



## OpenAPI

````yaml /api-reference/phones/tools.yaml post /devices/{deviceId}/browser/execute-script
openapi: 3.1.0
info:
  title: Tools
  version: v1
servers:
  - url: https://api.mobilerun.ai
    description: Droidrun Cloud API
security:
  - bearerAuth: []
paths:
  /devices/{deviceId}/browser/execute-script:
    post:
      tags:
        - Browser
      summary: Execute JavaScript in the device's Chrome browser (CDP)
      description: >-
        Evaluates a JavaScript expression in the device's foreground Chrome tab
        via the Chrome DevTools Protocol and returns its JSON-serialized result.
        Devices without browser support return an unsupported-feature error.
      operationId: browser-execute-script
      parameters:
        - in: path
          name: deviceId
          required: true
          schema:
            type: string
        - in: header
          name: X-Device-Display-ID
          schema:
            default: 0
            format: int64
            minimum: 0
            type: integer
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ExecuteScriptArgs'
        required: true
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ExecuteScriptOutputBody'
          description: OK
        default:
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/ErrorModel'
          description: Error
      security:
        - bearerAuth: []
components:
  schemas:
    ExecuteScriptArgs:
      additionalProperties: false
      properties:
        $schema:
          description: A URL to the JSON Schema for this object.
          examples:
            - https://example.com/schemas/ExecuteScriptArgs.json
          format: uri
          readOnly: true
          type: string
        script:
          description: >-
            JavaScript expression to evaluate in the device's foreground Chrome
            tab (CDP Runtime.evaluate). It is an expression, not a function body
            — the expression's value is returned (no top-level 'return'). Must
            evaluate to a JSON-serializable value; wrap multi-statement logic in
            an IIFE, e.g. (() => { ... ; return x })().
          type: string
      required:
        - script
      type: object
    ExecuteScriptOutputBody:
      additionalProperties: false
      properties:
        $schema:
          description: A URL to the JSON Schema for this object.
          examples:
            - https://example.com/schemas/ExecuteScriptOutputBody.json
          format: uri
          readOnly: true
          type: string
        result:
          description: >-
            JSON-serialized return value of the script (null if it returned
            undefined). Non-JSON-serializable numbers (Infinity, NaN, -0) are
            returned as their string representation.
      required:
        - result
      type: object
    ErrorModel:
      additionalProperties: false
      properties:
        $schema:
          description: A URL to the JSON Schema for this object.
          examples:
            - https://example.com/schemas/ErrorModel.json
          format: uri
          readOnly: true
          type: string
        detail:
          description: >-
            A human-readable explanation specific to this occurrence of the
            problem.
          examples:
            - Property foo is required but is missing.
          type: string
        errors:
          description: Optional list of individual error details
          items:
            $ref: '#/components/schemas/ErrorDetail'
          type:
            - array
            - 'null'
        instance:
          description: >-
            A URI reference that identifies the specific occurrence of the
            problem.
          examples:
            - https://example.com/error-log/abc123
          format: uri
          type: string
        status:
          description: HTTP status code
          examples:
            - 400
          format: int64
          type: integer
        title:
          description: >-
            A short, human-readable summary of the problem type. This value
            should not change between occurrences of the error.
          examples:
            - Bad Request
          type: string
        type:
          default: about:blank
          description: A URI reference to human-readable documentation for the error.
          examples:
            - https://example.com/errors/example
          format: uri
          type: string
      type: object
    ErrorDetail:
      additionalProperties: false
      properties:
        location:
          description: >-
            Where the error occurred, e.g. 'body.items[3].tags' or
            'path.thing-id'
          type: string
        message:
          description: Error message text
          type: string
        value:
          description: The value at the given location
      type: object
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: Opaque
      description: Bearer token via Authorization header

````