Runs one Fable operation selected by action. Use it for Fable sessions, gates, evidence/proofs, review rubrics, checkpoints, compression, design audits, research scrapers, and explicitly experimental System 3 operations; use browser_* tools for web-page navigation and interaction. Start stateful workflows with create_session and a session_name; later session actions reuse that name. Only fields documented for the selected action are read, and missing or invalid inputs return an Error: message without raising an MCP transport error. Status/list/telemetry/get/view/check operations are read-only. Create, log, record, set, advance, checkpoint, restore, track, evaluate, register, compress/accumulate, evolve, generate, and scraper operations can persist Fable state or artifacts. unlock_execution remains blocked until its time and rationale gates pass; apply_auto_update can replace installed Fable files. The result is action-specific human-readable text in result; inspect that text for success or Error: before continuing.

Opens a URL in the stealth agent browser using persistent local logins/profile (<=20 MB RAM ceiling). Supports local dev servers across all languages.

Loads url into an existing browser session, replacing its current document and adding a history entry. Use this instead of browser_open when continuing in a known session; if session_id is omitted, the active session is reused or a default session is created. It waits up to timeout seconds and returns the resulting URL, title, viewport, scroll position, and indexed elements; network, timeout, size, and parse failures return an error object without changing committed page state.

Activates an href-bearing link or submits a GET form through normal browser navigation. POST and other form methods are refused, and GET forms containing password fields are blocked to prevent credential leakage. Returns the resulting page status or a bounded error without bypassing existing navigation controls.

Replaces the full value of a text-like input or textarea identified by element_id; it does not submit the form. Use browser_press for single-key edits or activation. An omitted session_id targets the active/default session. Returns status typed, the element ID, and the supplied text; missing or non-editable elements return an error object and are not changed.

Scrolls the page vertically by delta pixels.

Captures up to max_layers PNGs from the top of the current document, one 1280x800 viewport per layer, without changing the session scroll position. Use this for multi-viewport page coverage; use browser_screenshot for only the current viewport. An omitted session_id targets the active/default session. Returns layer count, offsets, dimensions, and base64 PNG data; max_layers defaults to 3 and is capped at 10.

Captures one 1280x800 PNG of the current viewport without navigation or scroll changes. Use this for the visible region; use browser_snapshot_layers for multi-viewport coverage. An omitted session_id targets the active/default session. Returns one layer with its offset, dimensions, and base64 PNG data.

Closes and permanently discards one in-memory browser session, including its current document and history; persistent profile cookies remain saved. Use it when that tab is no longer needed. session_id targets a specific session; if omitted, the active session is closed. Returns closed, or not_found without changing another session.

Loads the previous history entry in the active or named browser session without adding a new history entry. Use it for history traversal rather than browser_navigate. If history is already at its first entry, it is a no-op that returns current page status. A navigation failure returns an error and preserves the history index; omitting session_id reuses or creates the active/default session.

Loads the next history entry in the active or named browser session without adding a new history entry. Use it after browser_back rather than browser_navigate. If no forward entry exists, it is a no-op that returns current page status. A navigation failure returns an error and preserves the history index; omitting session_id reuses or creates the active/default session.

Waits for a specified duration in seconds.

Edits supported text controls, moves focus with Tab, or activates links with Enter.

Reloads the current page in the browser session.