Theseus 0.3.109: Save page as PDF or PNG; connector design doc hosted on theseus.x

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The Claude connector's design doc now ships at
theseus.x/dev/claude-connector/DESIGN-claude-connector.md so readers
on the site do not have to leave for the forge; the Developers page
links the local copy first and the forge mirror alongside it.

dev/claude-connector/DESIGN-claude-connector.md

@@ -0,0 +1,208 @@
+# Claude connector — design and plan
+
+An opt-in MCP server built into Theseus, so a Claude client on the same
+computer (Claude Code, Claude Desktop) can work inside the user's real,
+signed-in profile: open a tab, read it, click, type, paste rich text into an
+editor, upload a file.
+
+## Why
+
+On 2026-10-22 a Claude Code session had to paste a prepared story into a
+Medium draft as the user's author account. The Claude desktop app's built-in
+browser could not do it: its synthetic paste arrived empty and its typed text
+never reached Medium's editor. The two other routes are worse:
+
+- `--remote-debugging-port` on the main profile opens a browser-wide DevTools
+  port. Any local process can attach and read every tab, cookie and session.
+- Theseus is a desktop app, and these sessions have no computer-use access to
+  drive it from outside.
+
+So the browser itself has to offer a narrow, user-controlled door.
+
+## Shape
+
+A built-in add-on, `bundled-addons/claude-connector/`, following the Pithos
+pattern: `activate(api)` starts a small HTTP server on `127.0.0.1` from the
+main process and registers a sidebar panel. What it needs from the browser
+that no add-on API offered yet comes through one new host capability,
+`tab-control`, which only built-in add-ons can hold.
+
+```
+Claude Code ──HTTP (Bearer token)──► 127.0.0.1:<port>/mcp ─┐
+Claude Desktop ─stdio─► stdio-shim.cjs ──HTTP──────────────┤
+                                                           ▼
+                                    claude-connector add-on (main process)
+                                      policy: allowlist · password guard · upload folders · log
+                                                           │ api.tabControl (tab-control capability)
+                                                           ▼
+                                    main.js: tabs, open/close/navigate, indicator
+                                                           │ webContents.debugger (CDP, per tab)
+                                                           ▼
+                                                    one tab's page
+```
+
+### Off by default
+
+- The add-on ships with `"defaultEnabled": false`. main.js puts any built-in
+  add-on with that flag into `settings.disabledAddons` the first time it sees
+  it (remembered in `settings.addonsDefaultOffSeen`, so the user's later
+  choice is never overridden). The user turns it on in **Settings ›
+  Extensions › Claude connector**.
+- While it is off, nothing listens. When it is on, the panel has a second
+  switch, **Accept connections**, on by default once the extension is
+  turned on, so the stop button can close the port without uninstalling
+  anything.
+
+### Transport and authentication
+
+- MCP **Streamable HTTP** at `http://127.0.0.1:<port>/mcp`. POST carries
+  JSON-RPC; GET opens an SSE stream (kept alive with comments, used as the
+  "connected" signal); DELETE ends a session.
+- Binds `127.0.0.1` only. The port is picked once per install (first free in
+  47800–47899, else any) and kept, so the config the user pasted stays valid.
+- A random 256-bit token per install, base64url. Every request needs
+  `Authorization: Bearer <token>`, compared in constant time.
+- DNS-rebinding and browser guard: the `Host` header must be
+  `127.0.0.1:<port>` or `localhost:<port>`, and any request carrying an
+  `Origin` header is refused. A web page cannot reach the server even if it
+  guessed the token.
+- **Revoke** in the panel issues a new token, which drops every client at
+  once. **Stop** (toolbar chip or panel) closes the port.
+- Claude Desktop speaks stdio, so the add-on ships `stdio-shim.cjs`, run by
+  the Theseus executable itself in Node mode (`ELECTRON_RUN_AS_NODE=1`, the
+  same mode the extension sandbox already uses). It reads the port from
+  `extensions-data/claude-connector/endpoint.json` and the token from
+  `THESEUS_MCP_TOKEN`, and relays line-delimited JSON-RPC to the HTTP endpoint.
+
+### Per-tab control, no browser-wide port
+
+- Each controlled tab gets `webContents.debugger` (CDP 1.3) attached on its
+  own webContents. No `--remote-debugging-port`, no DevTools target list.
+- main.js already attaches that debugger to freeze background tabs
+  (`setTabFrozen`). The connector shares the attachment: it attaches only if
+  nothing is attached, and detaches only what it attached itself.
+- Only ordinary web tabs (`http:`, `https:`) are controllable. Settings,
+  add-on pages, the home page, `file:` and internal schemes are refused:
+  a Settings tab would let a client switch the connector's own safety
+  settings.
+- A dormant restored tab is loaded and a frozen one thawed before it is used.
+  While a tab is controlled it gets focus emulation (`Emulation.
+  setFocusEmulationEnabled`), so editors that check `document.hasFocus()`
+  accept input while the Theseus window is in the background.
+
+### Host capability `tab-control` (addons-host.js + main.js)
+
+`api.tabControl`, built-in add-ons only, manifest must declare `tab-control`:
+
+| call | does |
+| --- | --- |
+| `list()` | every tab: id, title, url, kind (`web`/`settings`/`addon`/`home`), active, pending |
+| `webContents(id)` | the tab's webContents, after loading a dormant tab and thawing a frozen one; throws for non-web tabs |
+| `open(url, {background})` | new tab through main's own `createTab` (so BCNR names resolve as typed) |
+| `navigate(id, url)` | main's `navigateTab` |
+| `close(id)`, `activate(id)` | as the tab strip does |
+| `setStatus({connected, clients, busy, tabIds})` | drives the toolbar indicator and the per-tab marker |
+| `onStop(cb)` | the indicator's stop button |
+
+### Indicator
+
+- A chip in the toolbar, next to Downloads: **Claude** with a dot that pulses
+  while a tool call runs. Visible whenever a client is connected (an SSE
+  stream is open or a request arrived in the last 2 minutes). Clicking it
+  opens the connector panel; its ✕ stops the connector at once (closes the
+  port, ends sessions, detaches every debugger).
+- Each tab the client is controlling gets an outline marker in the tab strip.
+
+### Tools
+
+| tool | how |
+| --- | --- |
+| `list_tabs` | `tabControl.list()`; tabs on sites not yet approved show only their host |
+| `open_tab(url, background?)` | approval for the target origin first |
+| `navigate(tab_id, url \| action)` | url, or `back`/`forward`/`reload` |
+| `close_tab(tab_id)`, `activate_tab(tab_id)` | |
+| `screenshot(tab_id, full_page?)` | `Page.captureScreenshot`, scaled to CSS pixels so coordinates match `click(x, y)`; a hidden tab is brought to the front first (hidden views render no frames) |
+| `read_page_text(tab_id, max_chars?)` | `innerText` read in an isolated world |
+| `snapshot(tab_id, interactive_only?)` | `Accessibility.getFullAXTree`, compacted to `role "name" [ref=eN]` lines; refs map to `backendDOMNodeId` |
+| `click(tab_id, ref \| x,y)` | `DOM.scrollIntoViewIfNeeded` + `DOM.getContentQuads`, then `Input.dispatchMouseEvent` press/release |
+| `type(tab_id, text, ref?)` | `DOM.focus`, then `Input.insertText` per line and a real Enter (`Input.dispatchKeyEvent`) between lines; `mode: "keys"` sends every character as keyDown/keyUp |
+| `press_key(tab_id, key, modifiers?)` | Enter, Tab, Backspace, arrows, ctrl+a … |
+| `paste_html(tab_id, html, ref?)`, `paste_text(tab_id, text, ref?)` | write the real clipboard (`clipboard.write({html, text})`), `webContents.paste()`, then put the user's clipboard back |
+| `upload_file(tab_id, ref, path)` | `DOM.setFileInputFiles` on an `<input type=file>` |
+| `wait_for(tab_id, selector \| text, timeout_ms?)` | polls in an isolated world |
+| `evaluate(tab_id, expression)` | `Runtime.evaluate` in the page; listed only while **Allow evaluate** is on (off by default) |
+
+Page reads run in an isolated world (`Page.createIsolatedWorld`), so page
+scripts can neither see them nor tamper with the helpers.
+
+### Safety
+
+- **Per-site allowlist.** The first time a client acts on an origin (opens it,
+  navigates to it, reads or drives a tab on it), Theseus asks: *Allow Claude
+  to control medium.com?* — **Allow** (remembered), **This session only**, or
+  **Don't allow**. A refusal is remembered for 10 minutes, so a client cannot
+  spam the prompt. The panel lists approved sites with a remove button.
+- **Never types into password fields.** Before `type`, `press_key`,
+  `paste_*` and `evaluate`-free input, the focused element (followed into
+  shadow roots and same-origin frames) is checked in an isolated world:
+  `input[type=password]`, `autocomplete=current-password|new-password|
+  one-time-code`, or a cross-origin frame that cannot be inspected → refused.
+  `click` on a ref that is a password field is refused too, so a client
+  cannot focus one by ref and then type.
+- **Upload folders.** `upload_file` resolves the real path (symlinks and
+  junctions followed) and refuses anything outside the folders the user added
+  in the panel (none by default), anything that is not a regular file, and
+  files over 100 MB. The ref must be an `<input type=file>`.
+- **evaluate** is a separate switch, off by default, with a warning in the
+  panel: it runs arbitrary script as the page.
+- **Action log.** Every call is logged with an ISO timestamp, the tool, the
+  tab's origin, a short summary of the arguments (typed and pasted text is
+  logged by length and first 60 characters) and the outcome. The panel shows
+  the newest entries live; the log is kept in
+  `extensions-data/claude-connector/actions.log` (JSON lines, rotated at 1 MB).
+
+### What it does not defend against
+
+- A program already running as the user. The token sits in the add-on store
+  (`extensions-data/claude-connector.json`) next to the profile's cookies,
+  which such a program can read anyway. The connector keeps the door shut to
+  web pages and to other machines, and keeps the user in charge of which sites
+  a connected client may touch.
+- A site that changes a field's type after the focus check. The check runs
+  right before each input; what the page does in between is up to the page.
+
+## Files
+
+- `bundled-addons/claude-connector/` — `addon.json`, `index.js` (activate,
+  settings, panel messages), `lib/mcp-server.cjs` (HTTP + JSON-RPC +
+  sessions), `lib/tab-driver.cjs` (CDP per tab), `lib/tools.cjs` (tool
+  definitions and handlers), `lib/policy.cjs` (allowlist, upload paths,
+  password guard script), `lib/action-log.cjs`, `panel.html`,
+  `stdio-shim.cjs`, `README.md`.
+- `addons-host.js` — `tab-control` capability and `api.tabControl`.
+- `main.js` — the `tabControl` hook, indicator state, `defaultEnabled:false`
+  handling, `claude-connector` kept as a reserved first-party id.
+- `preload.js`, `chrome.html` — the indicator chip and the tab marker.
+- `tests/claude-connector.test.mjs` — launches Theseus on a scratch profile
+  (`THESEUS_USER_DATA`, `THESEUS_NO_UPDATE_CHECK`), with the connector
+  pre-enabled in that profile, and drives a local test page over MCP: type
+  into a rich editor, paste HTML with headings and links, upload a PNG,
+  refuse a password field and an upload outside the folder.
+- `tests/claude-connector-unit.test.mjs` — protocol, auth and policy checks
+  that run under plain Node.
+- README section with the `claude mcp add` command.
+
+## Steps
+
+1. Host: `tab-control` capability in addons-host.js; hook, indicator state,
+   default-off handling in main.js; chip in chrome.html/preload.js.
+2. Add-on: server, driver, tools, policy, log, panel, shim.
+3. Tests: unit (plain Node), then the Electron end-to-end test.
+4. Docs: README section, add-on README.
+
+## Not in this round
+
+- Cross-origin iframes (OOPIFs) are not driven; typing into one is refused
+  because its focused element cannot be checked.
+- No per-tool approval prompts beyond the per-site one.
+- No remote (non-loopback) clients, by design.

dev/index.html

@@ -282,8 +282,11 @@ GET /health</code></pre>
      (<code>evaluate</code>) is a separate switch, off by default. Every action is logged with its time.
      The toolbar chip's ✕ stops the connector at once; <i>Revoke token</i> cuts off every client you set
      up.</div>
-  <p>The connector ships with the next Theseus release after 0.3.106. Design notes:
-     <a href="https://code.silentmode.st/silentmode/theseus/src/branch/master/DESIGN-claude-connector.md">DESIGN-claude-connector.md ↗</a>.</p>
+  <p>Design notes:
+     <a href="claude-connector/DESIGN-claude-connector.md">DESIGN-claude-connector.md</a>
+     (hosted here &middot;
+     <a href="https://code.silentmode.st/silentmode/theseus/src/branch/master/DESIGN-claude-connector.md">forge mirror ↗</a>).
+     The connector shipped with Theseus 0.3.107.</p>
 </section>
 
 <section id="plug-ins">