@fetchproxy/cli

@fetchproxy/cli

fpx — a one-shot CLI for the fetchproxy bridge: authenticated fetches and session reads through the user's signed-in browser tab, straight from a shell prompt or a skill.

@fetchproxy/server and @fetchproxy/bootstrap are libraries an MCP server embeds. fpx is the same bridge wrapped as a standalone binary — no Node process to write, no MCP server to run. Point it at a URL, get the response on stdout; point it at a storage bucket, get JSON back. Useful anywhere a skill or shell script needs one authenticated request and doesn't want to carry a whole MCP.

Install

npm install -g @fetchproxy/cli

Or run it without installing:

npx @fetchproxy/cli profile list

Either way, the user also needs the fetchproxy browser extension (Transporter) installed — see the top-level README.

The profile model

fpx scopes every command to a named profile — a small JSON record describing one service: its declared domains, and (optionally) the cookie keys, storage keys, capture-headers, and IndexedDB scopes it's allowed to read. Profiles live at $FETCHPROXY_CLI_HOME/profiles.json, or ~/.fetchproxy/cli/profiles.json if that variable is unset.

fpx profile add opentable --domain opentable.com
fpx profile list
# opentable    opentable.com

Per-service identity

Each profile gets its own long-term identity, keyed by name: profile opentable connects to the bridge as fpx-opentable, with its identity keypair persisted at ~/.fetchproxy/identity/fpx-opentable.json. This mirrors how a real opentable-mcp would identify itself — the extension's trust store, pair history, and capability grants are all keyed off that per-service identity, not off fpx itself. Running fpx against ten services looks, from the extension's point of view, like ten independent MCPs.

Pair-code flow

The first time any verb connects under a given profile, the extension doesn't auto-trust it. fpx prints a 6-digit pair code to stderr:

$ fpx health -p opentable
fetchproxy pair code: 482-913 — approve in the Transporter extension popup

Open the Transporter popup, confirm the code matches, click Approve. Every subsequent command against that profile — from any verb — reuses the same trust record and skips the prompt.

Re-pair on scope change

fpx profile declare widens a profile's scope (more cookie keys, a new capture-header, etc.). Because the extension's trust is keyed to (identity, domains, capabilities), widening the scope changes the hello the next connection sends, and the extension treats that as a diff worth re-confirming:

fpx profile declare opentable --cookie oaid --capture-header [e-mail]
# profile "opentable" scope updated — the next connect will ask you to re-pair (scope diff)

The next command against opentable prints a fresh pair code even though the identity is unchanged.

Revocation

fpx profile remove <name> deletes the local profile entry and its identity file:

fpx profile remove opentable
# profile "opentable" removed — also revoke fpx-opentable in the Transporter extension popup

That only cleans up the CLI's side. The extension still holds a trust row for fpx-opentable until the user opens the Transporter popup and revokes it there — removing the profile does not reach into the browser.

Verbs

Every verb takes -p/--profile <name> (except the profile subcommands themselves, which take the name as a positional).

Command	What it does	Example
fpx profile add <name> --domain <apex>…	Create a profile with one or more declared domains.	fpx profile add opentable --domain opentable.com
fpx profile declare <name> [--cookie k]… [--local-storage k]… [--session-storage k]… [--capture-header name@host[/path]]… [--dom-selector handle=css]… [--allow-download]	Widen a profile's scope. Merges with the existing declaration; forces a re-pair.	fpx profile declare opentable --cookie oaid
fpx profile list	List all profiles and their domains (tab-separated, one per line).	fpx profile list
fpx profile show <name>	Print a profile's full JSON record.	fpx profile show opentable
fpx profile remove <name>	Delete the profile and its identity file.	fpx profile remove opentable
fpx pair -p <name> [--domain <apex>] [--subdomain <label>]	Force a pairing round-trip against one declared domain (defaults to the only one, if there's exactly one). --subdomain aims at the host your signed-in tab is actually on — the fetch tab-matcher is strict-prefix, so an apex-only profile won't match a www. tab.	fpx pair -p opentable --subdomain www
fpx health -p <name>	Print the bridge's health snapshot (host/peer role, connection state).	fpx health -p opentable
fpx get <url> -p <name> [--json] [-H 'K: V']…	GET a URL through the profile's tab.	fpx get https://www.opentable.com/ -p opentable
fpx post-json <url> <body|@file> -p <name> [--json] [-H 'K: V']…	POST a JSON body (literal or @file); sets Content-Type: application/json unless overridden.	fpx post-json https://www.opentable.com/dapi/fe/gql '{"operationName":"Autocomplete"}' -p opentable
fpx request <url> -p <name> [-X METHOD] [-H 'K: V']… [-d body|@file] [--json]	Arbitrary method/headers/body.	fpx request https://www.opentable.com/x -p opentable -X DELETE
fpx cookies [keys…] -p <name>	Read declared cookies (all declared keys if none given).	fpx cookies -p opentable
fpx local-storage [keys…] -p <name>	Read declared localStorage keys.	fpx local-storage authToken -p opentable
fpx session-storage [keys…] -p <name>	Read declared sessionStorage keys.	fpx session-storage csrfToken -p opentable
fpx indexeddb -p <name>	Read all declared IndexedDB scopes (no key arguments — scopes come from the profile).	fpx indexeddb -p opentable
fpx session -p <name> [--storage-domain d] [--storage-subdomain s]	Bootstrap-parity one-shot: pair (if needed), read every declared bucket, close, print the combined session JSON.	fpx session -p opentable
fpx dom <name…> -p <name> [--storage-domain d] [--storage-subdomain s]	Read declared DOM selector values (all declared selectors if no names given). Requires --dom-selector declarations.	fpx dom title -p opentable
fpx download <url> -p <name> [--filename f]	Download a URL through the browser's own network stack (chrome.downloads — real cookies + TLS fingerprint); prints {path, bytes, mime?, finalUrl?} for the saved local file. Requires --allow-download.	fpx download https://www.opentable.com/f.pdf -p opentable
fpx --version (or -v)	Print the CLI version to stdout. The version also appears in the fpx / fpx --help header.	fpx --version

--storage-domain / --storage-subdomain (on the storage-read verbs, session, and dom) select which declared domain to read from when a profile declares more than one — required only in that case, same as the underlying library.

--dom-selector <handle>=<css> (on profile declare) declares a named DOM read: <handle> is the logical name fpx dom references, <css> is the document.querySelector CSS selector the extension reads (first match only, no page-JS execution). --allow-download grants the profile the download capability, letting fpx download save a declared-domain URL through the browser's own network stack.

Output contract

• stdout carries data only — response bodies, --json envelopes, storage-read JSON, profile list/profile show output.
• Everything else goes to stderr — pair codes, status lines (profile "x" created …, paired ✓ …), hints, and error messages.

This split means fpx get … | jq . or fpx cookies -p x > cookies.json never picks up incidental noise.

Exit codes

Code	Meaning
0	Success.
1	Usage error — bad flags, unknown command, unknown profile, undeclared scope, malformed body.
2	Bridge unavailable — extension not connected, pairing still pending, or an unexpected bridge-level failure.
3	Bot wall detected in the response (Akamai/Cloudflare-style interstitial).
4	Upstream HTTP error — the request reached the site but got a non-2xx response.

Exit codes 3 and 4 are emitted only by the fetch verbs (get, post-json, request); the pair, health, session, read verbs (cookies/local-storage/session-storage/indexeddb), dom, and download all return 0 on a successful bridge round-trip regardless of upstream status.

FETCHPROXY_CLI_HOME

Profiles are stored at $FETCHPROXY_CLI_HOME/profiles.json if that environment variable is set, otherwise at ~/.fetchproxy/cli/profiles.json. Set it to isolate fpx state per-shell, per-CI-job, or for a smoke test:

FETCHPROXY_CLI_HOME=$(mktemp -d) fpx profile add scratch --domain example.com

Per-service identity files are unaffected by this variable — they always live at ~/.fetchproxy/identity/fpx-<name>.json.

Capability parity

Every verb — get, post-json, request, cookies, local-storage, session-storage, indexeddb, dom, download, even health and pair — derives its hello frame from the full profile record via the same serverOptsFor() helper, not just the fields that particular verb happens to touch. That's deliberate: the extension's trust is keyed to (identity, domains, capabilities), so if fpx get sent a narrower hello than fpx cookies, alternating between the two verbs on the same profile would look like a capability change and force a re-pair every time. Sending the same hello for every verb means you can freely interleave fpx get, fpx cookies, fpx dom, etc. against one profile and only ever pair once — a re-pair only happens when fpx profile declare actually changes the stored scope.

One exception: fpx session goes through @fetchproxy/bootstrap directly, not serverOptsFor(), and bootstrap has no concept of domSelectors/download — those two fields only exist for fpx's own dom/download verbs. So a profile that declares --dom-selector/--allow-download sends a wider hello on the direct verbs than fpx session does. In practice this costs nothing but a one-time, non-blocking re-pair the first time you alternate between fpx session and fpx dom/fpx download on such a profile — the same self-healing behavior already accepted for the storage-pointer scopes.

Skills

fpx is designed to be the thing a skill shells out to when it needs one authenticated read, without embedding a bridge client. A typical pattern:

# One-time setup (pairs interactively):
fpx profile add opentable --domain opentable.com
fpx pair -p opentable

# From then on, any skill script can do:
fpx get -p opentable 'https://www.opentable.com/dapi/fe/gql?...' --json | jq .body

Or, scoped to a declared cookie for a lightweight auth check:

fpx cookies oaid -p opentable | jq -r .oaid

Because pairing is per-profile and persists across invocations, a skill can call fpx repeatedly across a session — once per tool call, even — without re-triggering the pair prompt after the first approval.