Sets a URL-substring breakpoint for a future XHR/Fetch when runtime request arguments, local variables, or payload construction must be inspected. For an already captured request, call get_request_initiator first because it is non-pausing; use this only when that evidence is insufficient. Set it before reproducing the user action—it does not inspect past traffic—then call get_paused_info/evaluate_script and finally step or resume. The URL pattern identifies this breakpoint for list_breakpoints and remove_breakpoint(action="remove_xhr").

Discard captured HTTP(S) evidence for the currently selected page after confirm=true. Use this immediately before reproducing an action when a clean network capture window is needed; do not use it to reset login, cookies, cache, or other browser state. It irreversibly clears the in-memory request queue, cached response bodies, and initiator maps only. Browser cookies, HTTP cache, origin storage, console messages, and WebSocket connections/messages are unchanged; use clear_site_data for cookie and storage reset. New captures continue above the previous reqid high-water mark because reqids are never reused.

Irreversibly clear browser state after confirm=true to create a clean replay environment for the selected page. Use this before replaying login, session creation, storage initialization, or other state-dependent flows; do not use it to inspect cookies or determine which response set one. For cookie provenance, including HttpOnly, Secure, and SameSite attributes, use list_network_requests with cookieName first. Cleanup covers cookies affecting the selected page's HTTP(S) frames—including HttpOnly and Secure cookies through the browser context—persistent storage for those frame origins, and each HTTP(S) frame's sessionStorage. It does not reload the page. The browser HTTP cache is global and is preserved by default; set clearBrowserCache=true only when that wider cross-page effect is explicitly intended.

Performs one verified, auditable click in the currently selected frame. Use it when the task requires activating a known button, link, or control after selecting the correct page/frame and identifying a CSS selector; it is the preferred minimal interaction primitive over arbitrary evaluate_script code. It does not discover elements, type text, or silently guess among matches: the selector must resolve to exactly one element unless index is explicit, and the chosen element must be visible. A click can submit data, navigate, or trigger external effects, so confirm=true is required and the result reports the exact resolved element.

Evaluates one focused JavaScript function for DOM/page state, web storage, page-defined globals, a paused-frame expression, or browser-side processing of one local file. Use it when those runtime values are the goal and no narrower evidence tool applies. Do not use document.cookie or page evaluation to investigate HttpOnly/Secure cookies, Set-Cookie provenance, or captured HTTP evidence; use list_network_requests with cookieName/reqid, and use search_in_sources/get_script_source for source discovery. While running, evaluation uses the selected frame's isolated world by default or its page main world with mainWorld=true; while paused, it always uses the chosen call frame and ignores mainWorld. Call get_paused_info before paused evaluation, then step or resume when finished. Arbitrary code can change page/external state and requires confirm=true; inline results are bounded, so use outputFile for exact large or binary results.

Inspects the current call stack, source locations, and selected call-frame scopes after a code/XHR breakpoint or explicit pause has stopped execution. It neither creates a pause nor resumes one. Returned frameIndex values and callFrameIds belong only to the current pause and expire after any step or resume; use evaluate_script with frameIndex for a focused expression, then step or pause_or_resume(action="resume").

Non-pausing first action for tracing which JavaScript initiated a retained HTTP request when CDP initiator evidence was active. Pass the reqid from list_network_requests; because initiator capture starts lazily and is not retroactive, an older request may have no stack—in that case reproduce the action and inspect the new reqid, or set break_on_xhr before reproduction when runtime values are required. If the captured stack identifies the code, inspect its URL/location with get_script_source. If arguments, locals, or a dynamically built payload are still needed, use break_on_xhr, reproduce, then call get_paused_info or evaluate_script before stepping or resuming. This tool only reads retained evidence and does not pause or reproduce the request.

Reads a small source region around a search match, paused location, or known statement without executing or pausing the page. Select by URL when available because URL-backed scripts can be resolved again after navigation; use the debugger-context-scoped scriptId only for current inline/eval scripts. Use line ranges for normal source and offset/length for minified single-line bundles. For a whole, minified, or WASM source, use save_script_source; to observe runtime values next, call set_breakpoint_on_text against the original loaded source.

Inspect captured bidirectional WebSocket connections and frame payloads for the selected page. Use this for WebSocket, socket, live-update, push, streaming, or realtime message flows; use list_network_requests for ordinary HTTP/XHR/fetch traffic and WebSocket upgrade request headers. WebSocket capture starts lazily on this tool's first use and is not retroactive: if the relevant socket already connected or exchanged frames, call this tool once to initialize capture, then reload or reproduce the flow. Without wsid it lists connections so you can choose one. With wsid it lists paginated sent/received frames; add show_content=true for payload previews. With wsid and analyze=true it groups frames by payload pattern and returns group IDs and sample frame indices; then use groupId to inspect one pattern. With wsid and frameIndex it returns one retained frame's detailed payload using the stable index shown in frame tables or analysis samples.

Inspects code and XHR/Fetch breakpoints managed by this MCP session before reproducing an action or cleaning up debugger state. Returns current code breakpointIds and the exact XHR URL patterns needed by remove_breakpoint; URL-backed definitions are restored after navigation when possible, but a rebuilt debugger session may assign new IDs. This does not show why or where execution is currently paused—use get_paused_info for the active call stack.

Inspects console messages and uncaught page errors captured for the selected page. Use it to diagnose runtime failures, warnings, application logs, or values already emitted by page code; use search_in_sources for source text and list_network_requests for HTTP evidence instead. Without msgid it lists messages 20 per page by default, optionally filtered by type or retained navigation history. With msgid it returns one message by its stable ID for focused inspection. Capture begins when this MCP attaches and is not retroactive, so reload or reproduce code that logged before attachment.

Inspect captured HTTP(S) traffic for the currently selected page. Use this for API calls, request or response headers and bodies, redirects, authentication/session flows, replay or signing inputs, and determining which response created, refreshed, rotated, overwritten, or deleted a cookie. Without reqid it lists and filters requests; with cookieName it traces exact response Set-Cookie updates oldest-first, including cookies with HttpOnly, Secure, or SameSite attributes that page JavaScript cannot fully inspect; with reqid it returns bounded request details; with reqid plus outputFile it exports exact data. To inspect complete Set-Cookie values and attributes, export outputPart="responseHeaders" for a reqid returned by cookieName mode. cookieName never searches outbound Cookie request headers. Use get_websocket_messages for WebSocket frame payloads; this tool only represents the HTTP upgrade request. Capture begins when this MCP attaches and is not retroactive, so reload or reproduce traffic that occurred earlier. Captures then survive navigation in a 5000-request FIFO queue. List and cookie-flow modes default to 20 items per page; filters combine with AND and multiple values inside one filter combine with OR.

Discovers JavaScript currently loaded in the selected debugger context—the main frame by default, or the frame chosen with select_frame. Use select_frame first for iframe-specific source/debugger work. Includes external, inline, and eval scripts in that context; if you already know a function name, endpoint, or code literal, use search_in_sources instead. Each result includes a context-scoped scriptId that expires on reload, navigation, or debugger target change and, for external scripts, a URL that is the preferred selector for get_script_source or save_script_source.

Navigates, reloads, or moves through history in the currently selected page. Use it to reproduce requests, trigger configured breakpoints, refresh scripts, or continue a workflow in the same tab; use new_page when a separate tab is required. It does not clear cookies, storage, cache, or site data, so call clear_site_data first only when a clean replay is intended. It waits for DOMContentLoaded rather than every background resource; if a breakpoint pauses loading, use get_paused_info and then pause_or_resume(action="resume"). Navigation invalidates old script IDs, while tracked URL and XHR/Fetch breakpoints are restored when possible.

Opens a separate browser page for a URL, reusing an existing about:blank startup tab when available. Use this when the task needs another tab or should preserve the currently selected page; use navigate_page to change the URL in the existing selected page instead. It waits for DOMContentLoaded, not every background resource, and then makes the opened page the target for later tools. It preserves cookies, storage, cache, and other browser state; use clear_site_data separately when a clean replay is required.

Explicitly requests an immediate pause or resumes an existing paused execution; it never toggles implicitly. Use a code breakpoint or break_on_xhr instead when a specific statement/request should stop, and use get_paused_info before resuming if evidence must be collected. Resuming invalidates current callFrameIds and frame indices.

Removes a known code breakpoint, XHR/Fetch breakpoint, or every MCP-managed breakpoint after explicit confirmation. Use breakpointId from set_breakpoint_on_text/list_breakpoints for remove_code, or reuse the exact URL pattern from break_on_xhr/list_breakpoints for remove_xhr. Removal does not resume an already paused page; call pause_or_resume(action="resume") separately after inspection.

Saves one complete JavaScript or WASM source for local inspection when an inline snippet is insufficient, especially for large or minified bundles. Prefer get_script_source for a small known region and search_in_sources to locate text across loaded scripts first. With format=true, destinations using a supported JavaScript/TypeScript extension are formatted by default; other extensions preserve raw source, and formatted line numbers may differ from the live page. Use distinctive text plus the original URL with set_breakpoint_on_text for runtime debugging. The returned filename is the resolved local path, while scriptId remains scoped to the current debugger context.

Finds a known function name, endpoint, string literal, token, or code pattern in JavaScript loaded by the selected debugger context—the main frame by default, or the frame chosen with select_frame. It searches external, inline/eval, and minified sources in that context without executing or pausing the page, returning 1-based lines plus context-scoped scriptIds; URLs are the preferred selectors for URL-backed matches. Use select_frame first for iframe-specific source work, get_script_source for nearby context, save_script_source for a whole bundle, or set_breakpoint_on_text when runtime values are needed. For a known captured request, prefer get_request_initiator before a broad source search.

Lists or selects frames, including iframes, within the current page. Use it when the target element, page-defined global, script, or execution context may live in an iframe: first list frames, then pass frameIdx before click_element or evaluate_script. Omitting frameIdx lists 20 frames per page without changing context; passing frameIdx changes the shared frame target, with 0 restoring the main frame. It does not switch browser tabs or navigate—use select_page or navigate_page for those actions—and listPageIdx only paginates this listing.

Lists or selects open browser pages. Use it without pageIdx to identify the active page or choose the correct tab before inspecting network traffic, scripts, frames, or console output; pass pageIdx to make one listed page the shared target for later tools. It does not navigate or create pages: use navigate_page to change the selected page's URL and new_page when a separate tab is required. listPageIdx only paginates the page listing and never changes selection.

Sets a restorable URL-backed breakpoint when distinctive code text is known and its runtime values must be observed. Call it directly when the user already supplies precise text plus any URL/occurrence disambiguation; use search_in_sources/get_script_source first only when the location is unknown or ambiguous. For an API with no known code location, start with list_network_requests and get_request_initiator or use break_on_xhr. On a hit, call get_paused_info, optionally evaluate_script, then step or resume. Returns the current breakpointId for remove_breakpoint; list breakpoints again after a rebuilt debugger session, and note that unnamed inline/eval scripts cannot use this URL breakpoint.

Advances JavaScript execution by one debugger operation from an existing pause and returns the next stopped call frame with concise source context. Use after get_paused_info or evaluate_script when control flow still needs tracing; it cannot start from running execution. Each advance invalidates prior callFrameIds, so inspect the new pause again as needed, then use pause_or_resume(action="resume") to finish.

Captures the visual state of the currently selected page. Use it to verify page layout, visible UI state, selector targets, in-page dialogs/modals, or the effect of a navigation/click; it is not a substitute for DOM values, network evidence, or script inspection. By default it returns the visible viewport, while fullPage=true captures the whole document; oversized captures may be saved as a temporary artifact instead of attached. Pass filePath for a reusable local artifact; existing files require confirmOverwrite=true and remain subject to --allowedRoots.