Check tools

`verify_start`

Start a check: Mobster prepares its simulator, launches the app and fixes the expectations. Drive the app, then call verify_finish; with smart, Mobster runs the steps and you wait. Acts on the device. Arguments

Name	Type	Default	Description
`app_path`	string		Absolute path to the .app built for the iOS Simulator; it is installed before the run.
`bundle_id`	string		The app’s bundle ID; read from `app_path` when omitted.
`device`	string		A device from `list_devices` (its id or name), or a simulator device type such as iPhone 17 Pro; a USB iPhone runs an app already on it (`bundle_id`). At most 128 characters.
`runtime`	string	the newest	The iOS runtime, such as iOS 26.4.
`reset`	string	reinstall with `app_path`, else data	App state cleared before launch. One of `none`, `data` or `reinstall`.
`launch_args`	array of strings		Launch arguments. At most 20 items.
`launch_env`	object		Launch environment variables, KEY to value.
`open_url`	string		A deep link opened after launch. At most 2,000 characters.
`name`	string		The check’s name in reports. At most 120 characters.
`steps`	array of strings	required	The steps: the ones you will take, or with smart the ones Mobster takes, in plain English; may be empty. At most 20 items. Each item: 1 to 500 characters.
`expect`	array of objects		The accessibility-tree assertions checked at `verify_finish`; declare ones that only hold after the steps. Required without smart. A navigation bar’s title is its id: {visible: {role: navbar, id: General}}. At most 50 items.
`image`	boolean	`true`	Include a 390-px-wide JPEG of the screen.
`smart`	boolean		Mobster runs the steps itself with `<model>`, on the user’s `<provider>` key; wait for the verdict.
`max_usd`	number	`0.25`	With smart, the run’s model spend cap in US dollars. More than 0 and at most 1.
`max_seconds`	number	`180`	With smart, the time limit for the steps. More than 0 and at most 600.

Fields of expect[]

Name	Type	Description
`text`	string	Holds when a shown element’s label or value contains this text, in any case.
`no_text`	string	Holds when no shown element’s label or value contains it.
`visible`	object	Holds when at least one shown element matches.
`absent`	object	Holds when no shown element matches.
`value`	object	With equals: exactly one shown element matches and its value equals it.
`count`	object	With equals, `at_least` or `at_most`: the number of shown elements that match.
`equals`	any	For value: text, a number or true/false; for count: a whole number.
`at_least`	integer	For count: at least this many. At least 0.
`at_most`	integer	For count: at most this many. At least 0.
`name`	string	A label for the report. At most 120 characters.

Fields of expect[].visible, expect[].absent, expect[].value and expect[].count

Name	Type	Description
`id`	string	The accessibility identifier, exactly or as /regex/.
`label`	string	The label, exactly or as /regex/ (add i for any case: /about/i).
`value`	string	The value, exactly or as /regex/; a switch reads 1 or 0.
`role`	string	Button, text, field, switch, cell, image, link, tab, slider, stepper, picker, segment, navbar or alert.
`enabled`	boolean	Whether the element is enabled.
`selected`	boolean	Whether the element is selected.

Example

tools/call params

{
  "name": "verify_start",
  "arguments": {
    "app_path": "/abs/path/YourApp/.mobster/build/Build/Products/Debug-iphonesimulator/YourApp.app",
    "launch_args": ["-SkipOnboarding", "YES"],
    "launch_env": {"SEED_TASKS": "3"},
    "open_url": "yourapp://tasks",
    "steps": ["Tap the first task to mark it done."],
    "expect": [
      {"visible": {"id": "task_1", "selected": true}},
      {"value": {"id": "done_count"}, "equals": 1},
      {"value": {"id": "tasks_left"}, "equals": 2}
    ]
  }
}

Returns The run’s status and run_id, as text and in structuredContent. While it is preparing, running (a Smart run) or finishing, call wait. At ready, screen holds the screen as an outline, with a JPEG of it unless the run started with image false. A finished run returns its verdict, as verify_finish does.

Input schema and annotations of verify_start

Annotations: title: "Start a check", readOnlyHint: false, destructiveHint: true, idempotentHint: false, openWorldHint: true

{
  "type": "object",
  "properties": {
    "app_path": {
      "type": "string",
      "description": "absolute path to the .app built for the iOS Simulator; it is installed before the run"
    },
    "bundle_id": {
      "type": "string",
      "description": "the app's bundle ID; read from app_path when omitted"
    },
    "device": {
      "type": "string",
      "maxLength": 128,
      "description": "a device from list_devices (its id or name), or a simulator device type such as iPhone 17 Pro; a USB iPhone runs an app already on it (bundle_id)"
    },
    "runtime": {
      "type": "string",
      "description": "the iOS runtime, such as iOS 26.4; default the newest"
    },
    "reset": {
      "type": "string",
      "enum": [
        "none",
        "data",
        "reinstall"
      ],
      "description": "app state cleared before launch; default reinstall with app_path, else data"
    },
    "launch_args": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "maxItems": 20,
      "description": "launch arguments"
    },
    "launch_env": {
      "type": "object",
      "additionalProperties": {
        "type": "string"
      },
      "description": "launch environment variables, KEY to value"
    },
    "open_url": {
      "type": "string",
      "maxLength": 2000,
      "description": "a deep link opened after launch"
    },
    "name": {
      "type": "string",
      "maxLength": 120,
      "description": "the check's name in reports"
    },
    "steps": {
      "type": "array",
      "items": {
        "type": "string",
        "minLength": 1,
        "maxLength": 500
      },
      "maxItems": 20,
      "description": "the steps: the ones you will take, or with smart the ones Mobster takes, in plain English; may be empty"
    },
    "expect": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "one assertion: exactly one of text, no_text, visible, absent, value, count",
        "properties": {
          "text": {
            "type": "string",
            "description": "holds when a shown element's label or value contains this text, in any case"
          },
          "no_text": {
            "type": "string",
            "description": "holds when no shown element's label or value contains it"
          },
          "visible": {
            "type": "object",
            "description": "holds when at least one shown element matches",
            "properties": {
              "id": {
                "type": "string",
                "description": "the accessibility identifier, exactly or as /regex/"
              },
              "label": {
                "type": "string",
                "description": "the label, exactly or as /regex/ (add i for any case: /about/i)"
              },
              "value": {
                "type": "string",
                "description": "the value, exactly or as /regex/; a switch reads 1 or 0"
              },
              "role": {
                "type": "string",
                "description": "button, text, field, switch, cell, image, link, tab, slider, stepper, picker, segment, navbar or alert"
              },
              "enabled": {
                "type": "boolean",
                "description": "whether the element is enabled"
              },
              "selected": {
                "type": "boolean",
                "description": "whether the element is selected"
              }
            },
            "additionalProperties": false
          },
          "absent": {
            "type": "object",
            "description": "holds when no shown element matches",
            "properties": {
              "id": {
                "type": "string",
                "description": "the accessibility identifier, exactly or as /regex/"
              },
              "label": {
                "type": "string",
                "description": "the label, exactly or as /regex/ (add i for any case: /about/i)"
              },
              "value": {
                "type": "string",
                "description": "the value, exactly or as /regex/; a switch reads 1 or 0"
              },
              "role": {
                "type": "string",
                "description": "button, text, field, switch, cell, image, link, tab, slider, stepper, picker, segment, navbar or alert"
              },
              "enabled": {
                "type": "boolean",
                "description": "whether the element is enabled"
              },
              "selected": {
                "type": "boolean",
                "description": "whether the element is selected"
              }
            },
            "additionalProperties": false
          },
          "value": {
            "type": "object",
            "description": "with equals: exactly one shown element matches and its value equals it",
            "properties": {
              "id": {
                "type": "string",
                "description": "the accessibility identifier, exactly or as /regex/"
              },
              "label": {
                "type": "string",
                "description": "the label, exactly or as /regex/ (add i for any case: /about/i)"
              },
              "value": {
                "type": "string",
                "description": "the value, exactly or as /regex/; a switch reads 1 or 0"
              },
              "role": {
                "type": "string",
                "description": "button, text, field, switch, cell, image, link, tab, slider, stepper, picker, segment, navbar or alert"
              },
              "enabled": {
                "type": "boolean",
                "description": "whether the element is enabled"
              },
              "selected": {
                "type": "boolean",
                "description": "whether the element is selected"
              }
            },
            "additionalProperties": false
          },
          "count": {
            "type": "object",
            "description": "with equals, at_least or at_most: the number of shown elements that match",
            "properties": {
              "id": {
                "type": "string",
                "description": "the accessibility identifier, exactly or as /regex/"
              },
              "label": {
                "type": "string",
                "description": "the label, exactly or as /regex/ (add i for any case: /about/i)"
              },
              "value": {
                "type": "string",
                "description": "the value, exactly or as /regex/; a switch reads 1 or 0"
              },
              "role": {
                "type": "string",
                "description": "button, text, field, switch, cell, image, link, tab, slider, stepper, picker, segment, navbar or alert"
              },
              "enabled": {
                "type": "boolean",
                "description": "whether the element is enabled"
              },
              "selected": {
                "type": "boolean",
                "description": "whether the element is selected"
              }
            },
            "additionalProperties": false
          },
          "equals": {
            "description": "for value: text, a number or true/false; for count: a whole number"
          },
          "at_least": {
            "type": "integer",
            "minimum": 0,
            "description": "for count: at least this many"
          },
          "at_most": {
            "type": "integer",
            "minimum": 0,
            "description": "for count: at most this many"
          },
          "name": {
            "type": "string",
            "maxLength": 120,
            "description": "a label for the report"
          }
        },
        "additionalProperties": false
      },
      "maxItems": 50,
      "description": "the accessibility-tree assertions checked at verify_finish; declare ones that only hold after the steps. Required without smart. A navigation bar's title is its id: {visible: {role: navbar, id: General}}."
    },
    "image": {
      "type": "boolean",
      "default": true,
      "description": "include a 390-px-wide JPEG of the screen (default true)"
    },
    "smart": {
      "type": "boolean",
      "description": "Mobster runs the steps itself with `<model>`, on the user's `<provider>` key; wait for the verdict"
    },
    "max_usd": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 1.0,
      "description": "with smart, the run's model spend cap in US dollars (default 0.25)"
    },
    "max_seconds": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 600,
      "description": "with smart, the time limit for the steps (default 180)"
    }
  },
  "required": [
    "steps"
  ],
  "additionalProperties": false
}

`wait`

Wait up to timeout_s seconds for a run that is preparing or running, and return what it became. Read-only. Arguments

Name	Type	Default	Description
`run_id`	string	required	The run’s id, from `verify_start`.
`timeout_s`	number	`40`	Seconds to wait. 1 to 50.

Example

tools/call params

{"name": "wait", "arguments": {"run_id": "20260928-151841-816e"}}

Input schema and annotations of wait

Annotations: title: "Wait for a run", readOnlyHint: true, destructiveHint: false, openWorldHint: false

{
  "type": "object",
  "properties": {
    "run_id": {
      "type": "string",
      "description": "the run's id, from verify_start"
    },
    "timeout_s": {
      "type": "number",
      "minimum": 1,
      "maximum": 50.0,
      "description": "seconds to wait (default 40)"
    }
  },
  "required": [
    "run_id"
  ],
  "additionalProperties": false
}

`verify_finish`

Judge the run by the expectations from verify_start and return the verdict, the proof frames and the report. Local. Arguments

Name	Type	Default	Description
`run_id`	string	required	The run’s id, from `verify_start`.
`image`	boolean	`true`	Include a 390-px-wide JPEG of the screen.

Example

tools/call params

{"name": "verify_finish", "arguments": {"run_id": "20260928-151841-816e"}}

Returns The verdict (passed, failed, needs_review or couldnt_run) and each assertion with what the screen showed. structuredContent has verdict, assertions, reason, report, run_dir, proof and cost_usd. With image true, the proof frame comes as a JPEG.

Input schema and annotations of verify_finish

Annotations: title: "Finish a check", readOnlyHint: false, destructiveHint: false, openWorldHint: false, idempotentHint: true

{
  "type": "object",
  "properties": {
    "run_id": {
      "type": "string",
      "description": "the run's id, from verify_start"
    },
    "image": {
      "type": "boolean",
      "default": true,
      "description": "include a 390-px-wide JPEG of the screen (default true)"
    }
  },
  "required": [
    "run_id"
  ],
  "additionalProperties": false
}

`stop`

Stop a run (its result is couldnt_run, class stopped), or release a device driven directly. Cancels. Arguments

Name	Type	Default	Description
`run_id`	string		The run’s id, from `verify_start` or a device tool.
`device`	string		A device from `list_devices` (its id or name): without `run_id`, drive it directly; with neither, drive this session’s own simulator. 1 to 128 characters.

Example

tools/call params

{"name": "stop", "arguments": {"run_id": "20260928-151841-816e"}}

Returns The run’s verdict, as verify_finish returns it: a run stopped before it finished is couldnt_run, class stopped. A run still in a step returns status stopping: call wait. A device driven directly is released, with the run’s steps and its frames folder.

Input schema and annotations of stop

Annotations: title: "Stop the run", readOnlyHint: false, destructiveHint: true, openWorldHint: false, idempotentHint: true

{
  "type": "object",
  "properties": {
    "run_id": {
      "type": "string",
      "description": "the run's id, from verify_start or a device tool"
    },
    "device": {
      "type": "string",
      "minLength": 1,
      "maxLength": 128,
      "description": "a device from list_devices (its id or name): without run_id, drive it directly; with neither, drive this session's own simulator"
    }
  },
  "required": [],
  "additionalProperties": false
}

`save_check`

Save a check as checks/<name>.yaml for mobster test and run_tests: from a finished check run, or a task in the Mobster app (its id from mobster history). Local. Arguments

Name	Type	Default	Description
`run_id`	string	required	The run’s id, from `verify_start`.
`name`	string	required	Lowercase letters, digits and dashes, such as paywall-plans. Matches `^[a-z0-9][a-z0-9-]{0,59}$`.

Example

tools/call params

{
  "name": "save_check",
  "arguments": {"run_id": "20260928-151841-816e", "name": "mark-task-done"}
}

Returns The saved file’s path and the mobster test command that runs it again. structuredContent has path and replaced.

Input schema and annotations of save_check

Annotations: title: "Save a check", readOnlyHint: false, destructiveHint: false, openWorldHint: false

{
  "type": "object",
  "properties": {
    "run_id": {
      "type": "string",
      "description": "the run's id, from verify_start"
    },
    "name": {
      "type": "string",
      "pattern": "^[a-z0-9][a-z0-9-]{0,59}$",
      "description": "lowercase letters, digits and dashes, such as paywall-plans"
    }
  },
  "required": [
    "run_id",
    "name"
  ],
  "additionalProperties": false
}

`status`

Report Mobster’s version, the simulator setup, whether Smart is available, where runs go, and the open run. Read-only. Arguments Takes no arguments. Example

tools/call params

{"name": "status", "arguments": {}}

Returns The Mobster version, whether Smart is on, the runs folder, the open run and the simulator setup. structuredContent has mobster_version, smart_available, smart_model, runs_dir, open_run and devices_open, with the simulator setup.

Input schema and annotations of status

Annotations: title: "Check Mobster", readOnlyHint: true, destructiveHint: false, openWorldHint: false

{
  "type": "object",
  "properties": {},
  "required": [],
  "additionalProperties": false
}

CLI

MCP

Settings and errors

Inside Mobster

`verify_start`

`wait`

`verify_finish`

`stop`

`save_check`

`status`

​verify_start

​wait

​verify_finish

​stop

​save_check

​status

`verify_start`

`wait`

`verify_finish`

`stop`

`save_check`

`status`