bookmarks-api/AGENTS.md

Agent handshake — Bookmarks API for Scripting and AI

An API add-on for Firefox to allow agentic and script-based management of user bookmarks.

Use this when working in this repo. The shipped product is extension/ only.

Do not edit places.sqlite while Firefox is open if this API is reachable.

Preconditions

1. Add-on loaded. Secrets are issued and stored in the add-on (toolbar → Manage clients). The options page does not need the native host.
2. Native host installed only if scripts should call in: powershell -NoProfile -File tools/install-native-host.ps1
3. Firefox running for those calls

If http://127.0.0.1:17634/health fails, the host is not up. If /health works but calls 401, you do not have a current FAB_TOKEN.

Auth

This is a normal API token, not an SSH key.

1. In Firefox, open the Bookmarks API toolbar icon → Manage clients.
2. Name the client (e.g. cursor-agent) and click Generate secret.
3. Copy the fab_… value once. Store it however you already store secrets: env var, Vaultwarden, .env, CI secret, Cursor env.
4. Give tooling only that string:

set FAB_TOKEN=fab_…
python tools/client.py meta.methods

FAB_TOKEN_FILE pointing at a file that contains only the token is also fine. --token on the CLI overrides both.

The add-on stores SHA-256(token) only. Revoke from the same page. A local process that never received the secret cannot call the API.

Preferred caller

python tools/client.py METHOD [ARGS_JSON]

ARGS_JSON is a JSON array matching the WebExtension function arguments.

python tools/client.py bookmarks.search "[{\"title\":\"10.132.x.x\"}]"

HTTP:

POST /v1/call
Authorization: Bearer fab_…
Content-Type: application/json

{"method": "bookmarks.search", "args": [{"title": "10.132.x.x"}]}

Allowlisted methods (v0.2)

Method	Args	Notes
meta.ping	(none)	Bridge alive
meta.methods	(none)	This table
bookmarks.getTree	(none)	Full tree
bookmarks.getSubTree	id
bookmarks.getChildren	id
bookmarks.get	id or [id, …]
bookmarks.search	{title? url? query?} or string
bookmarks.create	{parentId?, title, url?}	Omit url to create a folder
bookmarks.update	id, {title? url?}
bookmarks.move	id, {parentId? index?}
bookmarks.remove	id	Bookmark or empty folder
bookmarks.removeTree	id	Folder and descendants
bookmarks.getRecent	numberOfItems

Do not invent other browser.* names. Adding an API means editing ALLOWED in extension/background.js and reloading the extension.

REST aliases use the same Bearer token. GET /health has no token (loopback liveness only).

Typical folder replace

1. bookmarks.search {title: "…"} — take the hit without a url. Fail if zero or many.
2. bookmarks.getChildren on that id.
3. bookmarks.remove each bookmark; bookmarks.removeTree each child folder.
4. bookmarks.create each new item with parentId set.

examples/replace_named_folder.py does that (FAB_TOKEN must be set).

Failure modes

Symptom	Cause	What to do
Connection refused on :17634	Firefox closed or add-on/host missing	Open Firefox; load add-on; install native host
401 Bearer token required	Unsigned request	Set FAB_TOKEN
401 unknown token	Revoked, typo, or never generated	Manage clients → generate again
502 method not allowed	Typo or API not in ALLOWED	meta.methods
Temporary add-on gone after restart	Unsigned on Firefox Release	Load again, or sign via AMO

Security boundaries

• No runtime.onMessageExternal. Other add-ons cannot call the dispatcher.
• Native host allowed_extensions is pinned to this add-on's gecko id.
• HTTP is 127.0.0.1 only; browser Origin headers are rejected.
• Secrets are ordinary Bearer tokens. Do not write them under %LOCALAPPDATA%\firefox-agent-bridge.
• Another add-on with the bookmarks permission already has Places.
• Do not add tabs, history, <all_urls>, or onMessageExternal without a new threat review.

What this project is not

• Not a bidirectional sync implementation
• Not a general Firefox remote-control surface
• Not a reason to keep editing places.sqlite on a live profile