hermes-agent/website
Teknium 5a1c599412
feat(browser): CDP supervisor — dialog detection + response + cross-origin iframe eval (#14540)
* docs: browser CDP supervisor design (for upcoming PR)

Design doc ahead of implementation — dialog + iframe detection/interaction
via a persistent CDP supervisor. Covers backend capability matrix (verified
live 2026-04-23), architecture, lifecycle, policy, agent surface, PR split,
non-goals, and test plan.

Supersedes #12550.

No code changes in this commit.

* feat(browser): add persistent CDP supervisor for dialog + frame detection

Single persistent CDP WebSocket per Hermes task_id that subscribes to
Page/Runtime/Target events and maintains thread-safe state for pending
dialogs, frame tree, and console errors.

Supervisor lives in its own daemon thread running an asyncio loop;
external callers use sync API (snapshot(), respond_to_dialog()) that
bridges onto the loop.

Auto-attaches to OOPIF child targets via Target.setAutoAttach{flatten:true}
and enables Page+Runtime on each so iframe-origin dialogs surface through
the same supervisor.

Dialog policies: must_respond (default, 300s safety timeout),
auto_dismiss, auto_accept.

Frame tree capped at 30 entries + OOPIF depth 2 to keep snapshot
payloads bounded on ad-heavy pages.

E2E verified against real Chrome via smoke test — detects + responds
to main-frame alerts, iframe-contentWindow alerts, preserves frame
tree, graceful no-dialog error path, clean shutdown.

No agent-facing tool wiring in this commit (comes next).

* feat(browser): add browser_dialog tool wired to CDP supervisor

Agent-facing response-only tool. Schema:
  action: 'accept' | 'dismiss' (required)
  prompt_text: response for prompt() dialogs (optional)
  dialog_id: disambiguate when multiple dialogs queued (optional)

Handler:
  SUPERVISOR_REGISTRY.get(task_id).respond_to_dialog(...)

check_fn shares _browser_cdp_check with browser_cdp so both surface and
hide together. When no supervisor is attached (Camofox, default
Playwright, or no browser session started yet), tool is hidden; if
somehow invoked it returns a clear error pointing the agent to
browser_navigate / /browser connect.

Registered in _HERMES_CORE_TOOLS and the browser / hermes-acp /
hermes-api-server toolsets alongside browser_cdp.

* feat(browser): wire CDP supervisor into session lifecycle + browser_snapshot

Supervisor lifecycle:
  * _get_session_info lazy-starts the supervisor after a session row is
    materialized — covers every backend code path (Browserbase, cdp_url
    override, /browser connect, future providers) with one hook.
  * cleanup_browser(task_id) stops the supervisor for that task first
    (before the backend tears down CDP).
  * cleanup_all_browsers() calls SUPERVISOR_REGISTRY.stop_all().
  * /browser connect eagerly starts the supervisor for task 'default'
    so the first snapshot already shows pending_dialogs.
  * /browser disconnect stops the supervisor.

CDP URL resolution for the supervisor:
  1. BROWSER_CDP_URL / browser.cdp_url override.
  2. Fallback: session_info['cdp_url'] from cloud providers (Browserbase).

browser_snapshot merges supervisor state (pending_dialogs + frame_tree)
into its JSON output when a supervisor is active — the agent reads
pending_dialogs from the snapshot it already requests, then calls
browser_dialog to respond. No extra tool surface.

Config defaults:
  * browser.dialog_policy: 'must_respond' (new)
  * browser.dialog_timeout_s: 300 (new)
No version bump — new keys deep-merge into existing browser section.

Deadlock fix in supervisor event dispatch:
  * _on_dialog_opening and _on_target_attached used to await CDP calls
    while the reader was still processing an event — but only the reader
    can set the response Future, so the call timed out.
  * Both now fire asyncio.create_task(...) so the reader stays pumping.
  * auto_dismiss/auto_accept now actually close the dialog immediately.

Tests (tests/tools/test_browser_supervisor.py, 11 tests, real Chrome):
  * supervisor start/snapshot
  * main-frame alert detection + dismiss
  * iframe.contentWindow alert
  * prompt() with prompt_text reply
  * respond with no pending dialog -> clean error
  * auto_dismiss clears on event
  * registry idempotency
  * registry stop -> snapshot reports inactive
  * browser_dialog tool no-supervisor error
  * browser_dialog invalid action
  * browser_dialog end-to-end via tool handler

xdist-safe: chrome_cdp fixture uses a per-worker port.
Skipped when google-chrome/chromium isn't installed.

* docs(browser): document browser_dialog tool + CDP supervisor

- user-guide/features/browser.md: new browser_dialog section with
  workflow, availability gate, and dialog_policy table
- reference/tools-reference.md: row for browser_dialog, tool count
  bumped 53 -> 54, browser tools count 11 -> 12
- reference/toolsets-reference.md: browser_dialog added to browser
  toolset row with note on pending_dialogs / frame_tree snapshot fields

Full design doc lives at
developer-guide/browser-supervisor.md (committed earlier).

* fix(browser): reconnect loop + recent_dialogs for Browserbase visibility

Found via Browserbase E2E test that revealed two production-critical issues:

1. **Supervisor WebSocket drops when other clients disconnect.** Browserbase's
   CDP proxy tears down our long-lived WebSocket whenever a short-lived
   client (e.g. agent-browser CLI's per-command CDP connection) disconnects.
   Fixed with a reconnecting _run loop that re-attaches with exponential
   backoff on drops. _page_session_id and _child_sessions are reset on each
   reconnect; pending_dialogs and frames are preserved across reconnects.

2. **Browserbase auto-dismisses dialogs server-side within ~10ms.** Their
   Playwright-based CDP proxy dismisses alert/confirm/prompt before our
   Page.handleJavaScriptDialog call can respond. So pending_dialogs is
   empty by the time the agent reads a snapshot on Browserbase.

   Added a recent_dialogs ring buffer (capacity 20) that retains a
   DialogRecord for every dialog that opened, with a closed_by tag:
     * 'agent'       — agent called browser_dialog
     * 'auto_policy' — local auto_dismiss/auto_accept fired
     * 'watchdog'    — must_respond timeout auto-dismissed (300s default)
     * 'remote'      — browser/backend closed it on us (Browserbase)

   Agents on Browserbase now see the dialog history with closed_by='remote'
   so they at least know a dialog fired, even though they couldn't respond.

3. **Page.javascriptDialogClosed matching bug.** The event doesn't include a
   'message' field (CDP spec has only 'result' and 'userInput') but our
   _on_dialog_closed was matching on message. Fixed to match by session_id
   + oldest-first, with a safety assumption that only one dialog is in
   flight per session (the JS thread is blocked while a dialog is up).

Docs + tests updated:
  * browser.md: new availability matrix showing the three backends and
    which mode (pending / recent / response) each supports
  * developer-guide/browser-supervisor.md: three-field snapshot schema
    with closed_by semantics
  * test_browser_supervisor.py: +test_recent_dialogs_ring_buffer (12/12
    passing against real Chrome)

E2E verified both backends:
  * Local Chrome via /browser connect: detect + respond full workflow
    (smoke_supervisor.py all 7 scenarios pass)
  * Browserbase: detect via recent_dialogs with closed_by='remote'
    (smoke_supervisor_browserbase_v2.py passes)

Camofox remains out of scope (REST-only, no CDP) — tracked for
upstream PR 3.

* feat(browser): XHR bridge for dialog response on Browserbase (FIXED)

Browserbase's CDP proxy auto-dismisses native JS dialogs within ~10ms, so
Page.handleJavaScriptDialog calls lose the race. Solution: bypass native
dialogs entirely.

The supervisor now injects Page.addScriptToEvaluateOnNewDocument with a
JavaScript override for window.alert/confirm/prompt. Those overrides
perform a synchronous XMLHttpRequest to a magic host
('hermes-dialog-bridge.invalid'). We intercept those XHRs via Fetch.enable
with a requestStage=Request pattern.

Flow when a page calls alert('hi'):
  1. window.alert override intercepts, builds XHR GET to
     http://hermes-dialog-bridge.invalid/?kind=alert&message=hi
  2. Sync XHR blocks the page's JS thread (mirrors real dialog semantics)
  3. Fetch.requestPaused fires on our WebSocket; supervisor surfaces
     it as a pending dialog with bridge_request_id set
  4. Agent reads pending_dialogs from browser_snapshot, calls browser_dialog
  5. Supervisor calls Fetch.fulfillRequest with JSON body:
     {accept: true|false, prompt_text: '...', dialog_id: 'd-N'}
  6. The injected script parses the body, returns the appropriate value
     from the override (undefined for alert, bool for confirm, string|null
     for prompt)

This works identically on Browserbase AND local Chrome — no native dialog
ever fires, so Browserbase's auto-dismiss has nothing to race. Dialog
policies (must_respond / auto_dismiss / auto_accept) all still work.

Bridge is installed on every attached session (main page + OOPIF child
sessions) so iframe dialogs are captured too.

Native-dialog path kept as a fallback for backends that don't auto-dismiss
(so a page that somehow bypasses our override — e.g. iframes that load
after Fetch.enable but before the init-script runs — still gets observed
via Page.javascriptDialogOpening).

E2E VERIFIED:
  * Local Chrome: 13/13 pytest tests green (12 original + new
    test_bridge_captures_prompt_and_returns_reply_text that asserts
    window.__ret === 'AGENT-SUPPLIED-REPLY' after agent responds)
  * Browserbase: smoke_bb_bridge_v2.py runs 4/4 PASS:
    - alert('BB-ALERT-MSG') dismiss → page.alert_ret = undefined ✓
    - prompt('BB-PROMPT-MSG', 'default-xyz') accept with 'AGENT-REPLY'
      → page.prompt_ret === 'AGENT-REPLY' ✓
    - confirm('BB-CONFIRM-MSG') accept → page.confirm_ret === true ✓
    - confirm('BB-CONFIRM-MSG') dismiss → page.confirm_ret === false ✓

Docs updated in browser.md and developer-guide/browser-supervisor.md —
availability matrix now shows Browserbase at full parity with local
Chrome for both detection and response.

* feat(browser): cross-origin iframe interaction via browser_cdp(frame_id=...)

Adds iframe interaction to the CDP supervisor PR (was queued as PR 2).

Design: browser_cdp gets an optional frame_id parameter. When set, the
tool looks up the frame in the supervisor's frame_tree, grabs its child
cdp_session_id (OOPIF session), and dispatches the CDP call through the
supervisor's already-connected WebSocket via run_coroutine_threadsafe.

Why not stateless: on Browserbase, each fresh browser_cdp WebSocket
must re-negotiate against a signed connectUrl. The session info carries
a specific URL that can expire while the supervisor's long-lived
connection stays valid. Routing via the supervisor sidesteps this.

Agent workflow:
  1. browser_snapshot → frame_tree.children[] shows OOPIFs with is_oopif=true
  2. browser_cdp(method='Runtime.evaluate', frame_id=<OOPIF frame_id>,
                 params={'expression': 'document.title', 'returnByValue': True})
  3. Supervisor dispatches the call on the OOPIF's child session

Supervisor state fixes needed along the way:
  * _on_frame_detached now skips reason='swap' (frame migrating processes)
  * _on_frame_detached also skips when the frame is an OOPIF with a live
    child session — Browserbase fires spurious remove events when a
    same-origin iframe gets promoted to OOPIF
  * _on_target_detached clears cdp_session_id but KEEPS the frame record
    so the agent still sees the OOPIF in frame_tree during transient
    session flaps

E2E VERIFIED on Browserbase (smoke_bb_iframe_agent_path.py):
  browser_cdp(method='Runtime.evaluate',
              params={'expression': 'document.title', 'returnByValue': True},
              frame_id=<OOPIF>)
  → {'success': True, 'result': {'value': 'Example Domain'}}

  The iframe is <iframe src='https://example.com/'> inside a top-level
  data: URL page on a real Browserbase session. The agent Runtime.evaluates
  INSIDE the cross-origin iframe and gets example.com's title back.

Tests (tests/tools/test_browser_supervisor.py — 16 pass total):
  * test_browser_cdp_frame_id_routes_via_supervisor — injects fake OOPIF,
    verifies routing via supervisor, Runtime.evaluate returns 1+1=2
  * test_browser_cdp_frame_id_missing_supervisor — clean error when no
    supervisor attached
  * test_browser_cdp_frame_id_not_in_frame_tree — clean error on bad
    frame_id

Docs (browser.md and developer-guide/browser-supervisor.md) updated with
the iframe workflow, availability matrix now shows OOPIF eval as shipped
for local Chrome + Browserbase.

* test(browser): real-OOPIF E2E verified manually + chrome_cdp uses --site-per-process

When asked 'did you test the iframe stuff' I had only done a mocked
pytest (fake injected OOPIF) plus a Browserbase E2E. Closed the
local-Chrome real-OOPIF gap by writing /tmp/dialog-iframe-test/
smoke_local_oopif.py:

  * 2 http servers on different hostnames (localhost:18905 + 127.0.0.1:18906)
  * Chrome with --site-per-process so the cross-origin iframe becomes a
    real OOPIF in its own process
  * Navigate, find OOPIF in supervisor.frame_tree, call
    browser_cdp(method='Runtime.evaluate', frame_id=<OOPIF>) which routes
    through the supervisor's child session
  * Asserts iframe document.title === 'INNER-FRAME-XYZ' (from the
    inner page, retrieved via OOPIF eval)

PASSED on 2026-04-23.

Tried to embed this as a pytest but hit an asyncio version quirk between
venv (3.11) and the system python (3.13) — Page.navigate hangs in the
pytest harness but works in standalone. Left a self-documenting skip
test that points to the smoke script + describes the verification.

chrome_cdp fixture now passes --site-per-process so future iframe tests
can rely on OOPIF behavior.

Result: 16 pass + 1 documented-skip = 17 tests in
tests/tools/test_browser_supervisor.py.

* docs(browser): add dialog_policy + dialog_timeout_s to configuration.md, fix tool count

Pre-merge docs audit revealed two gaps:

1. user-guide/configuration.md browser config example was missing the
   two new dialog_* knobs. Added with a short table explaining
   must_respond / auto_dismiss / auto_accept semantics and a link to
   the feature page for the full workflow.

2. reference/tools-reference.md header said '54 built-in tools' — real
   count on main is 54, this branch adds browser_dialog so it's 55.
   Fixed the header.  (browser count was already correctly bumped
   11 -> 12 in the earlier docs commit.)

No code changes.
2026-04-23 22:23:37 -07:00
..
docs feat(browser): CDP supervisor — dialog detection + response + cross-origin iframe eval (#14540) 2026-04-23 22:23:37 -07:00
scripts docs(website): dedicated page per bundled + optional skill (#14929) 2026-04-23 22:22:11 -07:00
src fix: light mode link/primary colors unreadable on white background (#10457) 2026-04-15 11:17:44 -07:00
static docs: stabilize website diagrams 2026-03-14 22:49:57 -07:00
.gitignore chore: gitignore generated skills.json 2026-04-02 10:48:15 -07:00
docusaurus.config.ts docs(site): disable highlightSearchTermsOnTargetPage to keep URLs clean (#12661) 2026-04-19 11:56:34 -07:00
package-lock.json docs: stabilize website diagrams 2026-03-14 22:49:57 -07:00
package.json fix(website): run skill extraction automatically on npm run build/start (#13747) 2026-04-21 18:02:04 -07:00
README.md docs: replace ASCII diagrams with Mermaid/lists, add linting note 2026-03-21 17:58:30 -07:00
sidebars.ts docs(website): dedicated page per bundled + optional skill (#14929) 2026-04-23 22:22:11 -07:00
tsconfig.json feat: add documentation website (Docusaurus) 2026-03-05 05:24:55 -08:00

Website

This website is built using Docusaurus, a modern static website generator.

Installation

yarn

Local Development

yarn start

This command starts a local development server and opens up a browser window. Most changes are reflected live without having to restart the server.

Build

yarn build

This command generates static content into the build directory and can be served using any static contents hosting service.

Deployment

Using SSH:

USE_SSH=true yarn deploy

Not using SSH:

GIT_USER=<Your GitHub username> yarn deploy

If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the gh-pages branch.

Diagram Linting

CI runs ascii-guard to lint docs for ASCII box diagrams. Use Mermaid (````mermaid`) or plain lists/tables instead of ASCII boxes to avoid CI failures.