io.github.chrischall/untappd-mcp

untappd-mcp

An MCP server for Untappd. It talks to Untappd's mobile (v4) API using your own account — search beers, breweries, and venues; read profiles, check-ins, wishlists, distinct beers, badges, friends, and your friend activity feed; and post check-ins, toasts, and comments.

Developed and maintained by AI (Claude Code). Use at your own discretion. This is an unofficial client that uses Untappd's private mobile API; it is not affiliated with or endorsed by Untappd.

How it works

Untappd's iPad/iPhone app authenticates with a username/password xauth login (POST https://api.untappd.com/v4/xauth) that returns an access token, then calls the v4 API. This server reproduces that, except where the token goes:

• Reads carry the token as an Authorization: Bearer header, never in the URL (the app uses an access_token query param; the API accepts both).
• Writes carry it as an Authorization: Bearer header (with the app's client credentials in the query), matching the app's real requests.

The token is fetched on demand, cached in memory, and refreshed automatically if it goes stale.

Configuration

Copy .env.example to .env and fill it in for local use.

Confirmations

Every write asks you to confirm it first. A client that can show a confirmation prompt (Claude Code) shows one (unless MCP_CONFIRM_ELICITATION=off). Elsewhere the write takes two calls: the first does nothing and returns a preview of the exact request plus a confirmToken, and only a repeat call with the same arguments and that token performs it. A token works once, for that tool and those arguments only; change anything and the call is refused with a fresh preview.

Obtaining the client id / secret

Untappd does not publish these; they live in the mobile app. Capture them from your own app's traffic with an HTTPS proxy:

1. Install a proxy such as mitmproxy and trust its CA certificate on the device running the Untappd app.
2. Point the device (or, on an Apple-silicon Mac running the iPad app, the Mac's system HTTP/HTTPS proxy) at the proxy.
3. Open Untappd and sign in. Find the POST https://api.untappd.com/v4/xauth request — its query string contains client_id and client_secret.
4. Put those into UNTAPPD_CLIENT_ID / UNTAPPD_CLIENT_SECRET.

Keep these values private; do not commit them.

Tools

Reads: untappd_search_beer, untappd_beer_info, untappd_beer_activity, untappd_search_brewery, untappd_brewery_info, untappd_brewery_beers, untappd_search_venue, untappd_venue_info, untappd_venue_activity, untappd_user_info, untappd_user_checkins, untappd_user_wishlist, untappd_user_beers, untappd_user_badges, untappd_user_friends, untappd_pending_friends, untappd_activity_feed, untappd_checkin_info, untappd_resolve, untappd_open_url, untappd_user_venues, untappd_venue_by_foursquare, untappd_trending, untappd_notifications, untappd_local_checkins, untappd_healthcheck.

Writes (each asks you to confirm first — see Confirmations): untappd_toast, untappd_add_comment, untappd_delete_comment, untappd_checkin, untappd_wishlist_add, untappd_wishlist_remove, untappd_delete_checkin, untappd_add_friend, untappd_accept_friend, untappd_reject_friend, untappd_remove_friend.

Check-in cache: untappd_sync_checkins, untappd_sync_user_beers, untappd_cache_has_had, untappd_cache_has_had_many, untappd_cache_not_had, untappd_cache_query, untappd_top_not_had, untappd_cache_status, untappd_cache_forget.

Menu picks: untappd_menu_pick (tap-list lines in, ranked not-had beers out), untappd_venue_pick (same, from a venue's Untappd menu).

Picking a beer off a menu

untappd_menu_pick turns "find Mer a beer" from a menu photo into one call. Give it the lines as read off the board:

{
  "username": "mer",
  "items": [
    "HAP & HARRY'S TENNESSEE LAGER $6",
    "I BELIEVE IN NASHVILLE BLONDE",
    "JACKALOPE FENNARIO IPA",
    "BEARDED IRIS HOMESTYLE",
    "BLACK ABBEY SEASONAL",
    "ROTATING CIDER"
  ],
  "venue_city": "Nashville",
  "top_n": 2
}

In one call it:

1. Freshens the cache. If the user's distinct-beers list is already complete it does an incremental refresh, stopping at the first beer that's cached and unchanged (usually one page). If the list is empty or partial it backfills in the same call until done or api_budget (default 60 calls, shared by every step) runs out. You never need to call a sync tool first.
2. Resolves each line to a beer. It strips prices, sizes, ABV and punctuation, searches Untappd (falling back to a query without the style word, because Untappd search matches every term), and scores the candidates on brewery match, beer-name match (so "Homestyle" isn't read as "Double Homestyle"), check-in volume (the canonical entry wins over a 3-check-in duplicate) and venue_city. Up to 4 searches run at once, and a 429 is retried with backoff. Resolutions are cached on disk, so the next visit to the same venue costs no searches.
3. Handles generic lines. <Brewery> SEASONAL / ROTATING becomes a possible list of that brewery's seasonal-looking beers, marked needs_confirmation. A line with no brewery (ROTATING CIDER) comes back unresolved: "ask bartender".
4. Checks every beer against the cache (both sources, as has_had_many does).
5. Ranks the not-had beers by global rating, applies style_filter, and returns the top top_n as picks.

Output for the call above, with Mer having had Fennario (abridged: not_had also lists the Tennessee Lager at 3.33, possible lists six candidates, and a freshness block is appended):

{
  "picks": [
    { "item": "BEARDED IRIS HOMESTYLE", "bid": 1502190, "name": "Homestyle", "brewery": "Bearded Iris Brewing",
      "style": "IPA - New England / Hazy", "abv": 6, "global_rating": 3.98,
      "reason": "not had · 3.98 global rating · #1 of 3 not-had beers on this list" },
    { "item": "I BELIEVE IN NASHVILLE BLONDE", "bid": 3780741, "name": "I Believe In Nashville",
      "brewery": "I Believe Brewing Company", "style": "Blonde / Golden Ale - American", "abv": 4.5,
      "global_rating": 3.54, "reason": "not had · 3.54 global rating · #2 of 3 not-had beers on this list" }
  ],
  "had": [
    { "item": "JACKALOPE FENNARIO IPA", "bid": 1893601, "name": "Fennario", "brewery": "Jackalope Brewing Company",
      "count": 3, "last_date": "2025-08-01T20:00:00.000Z", "user_rating": 3.75 }
  ],
  "possible": [
    { "item": "BLACK ABBEY SEASONAL", "brewery": "The Black Abbey Brewing Company",
      "reason": "seasonal-looking beers from this brewery",
      "candidates": [
        { "bid": 1223176, "name": "Chronicles Festbier", "style": "Festbier", "abv": 4.9, "global_rating": 3.672, "had": false }
      ],
      "needs_confirmation": true }
  ],
  "unresolved": [{ "item": "ROTATING CIDER", "reason": "ask bartender" }],
  "sync": { "mode": "backfill", "api_calls": 1 },
  "api_calls": 11,
  "api_budget": 60,
  "another_run_needed": false
}

sync says what the refresh did; coverage lives in freshness. If the budget runs out before the backfill finishes, freshness.coverage_complete is false, another_run_needed is true, and the freshness caveat warns that a "not had" may be a false negative. Calling again continues from where it stopped.

Quota. When an Untappd response carries X-Ratelimit-Remaining, the server remembers it for the hour, and every budgeted tool (menu_pick, venue_pick, top_not_had, both syncs) caps its budget to what's left. The result then includes quota_remaining, plus budget_clamped_to_quota: true when the cap applied. Untappd's public API documents the header; if the private API this server uses doesn't send it, budgets work exactly as before.

untappd_venue_pick takes an Untappd venue URL (https://untappd.com/v/<slug>/<id>) or id instead of items. It pages through the venue's whole verified menu, takes the venue's city from it, and runs the same check and ranking. Menu items already carry beer ids, so there is no search step.

Check-in cache

The Untappd API only exposes paged lists (50 per page) and has no "has this user ever had beer X?" lookup — answering that from the API alone means paging an entire history (often 11k+ check-ins) against a tight ~100-calls/hour rate limit. These tools maintain a SQLite mirror so the question is answered instantly, offline, with zero API calls. The mirror is a local SQLite file (node:sqlite, default ~/.untappd-mcp/checkins.db, overridable with UNTAPPD_CACHE_DB / UNTAPPD_CACHE_DIR). The store is injectable, so another deployment can back it differently without the tools changing.

Persistence. The file survives restarts, and a backfill that was cut off (rate limit, crash, host quit) resumes from its saved offset on the next sync. The file runs in WAL mode with a busy timeout and does every write in a transaction, so two hosts open at the same time can share it. The schema is versioned (PRAGMA user_version) and only ever migrated forward, adding columns and tables, so an upgrade never wipes it. untappd_cache_status shows the resolved path, size, schema version and per-user coverage.

Two sync sources fill the cache:

• untappd_sync_user_beers pages user/beers — the user's complete distinct-beers list (thousands of rows, not tens of thousands of check-ins). This is the cheapest way to get full "has had" coverage and, unlike user/checkins, it pages fully for any public/friend account. Start here for has-had questions.
• untappd_sync_checkins pages user/checkins for detailed check-ins (venue, date, comment). Only your own account pages fully — Untappd returns just the ~50 most recent for anyone else and won't page further, which the tool reports as history_truncated (it never falsely claims backfill_complete). Pass force_backfill: true to reset a cache wrongly marked complete and re-page from newest (cached rows are kept). Use this for recent venue/date detail; use untappd_sync_user_beers for coverage.

Both are resumable: they fetch max_pages per call (default 10), persist progress after every page, and set another_run_needed: true until done — just call again until it's false.

Query the cache with no further API calls. The has-had tools consult both sources (a hit in either counts as had):

• untappd_cache_has_had — has the user had a beer, by exact bid or a case-insensitive beer_name substring; returns count, best rating, last date, matching sources, and any detailed check-ins.
• untappd_cache_has_had_many — cross-check a whole list of bids in one call (e.g. a venue's menu) → had/not-had per beer.
• untappd_cache_not_had — given a list of bids, return just the ones the user has not had — the "what's new to me on this menu?" filter.
• untappd_top_not_had — from a list of bids, return the top N not-had beers ranked by Untappd global rating, with an optional style filter (the "what should I order off this tap list?" tool). Not-had filtering is cache-only; beer ratings come from a metadata cache (beer_meta) that's seeded opportunistically by untappd_beer_info / untappd_search_beer and topped up via beer/info only on a cache miss or entries older than 30 days — capped at api_budget calls/run (default 25), returning partial: true / another_run_needed: true when more are needed.
• untappd_cache_query — filter cached check-ins by brewery, style, min_rating, venue, and/or date range, with sorting and a limit.

Every read result carries a freshness block that reports each source's completeness separately (checkins.backfill_complete / history_truncated, beers.complete, per-source percentages) plus coverage_complete, and a caveat while coverage is incomplete — so a "not found" can be flagged as possibly a false negative until the relevant sync finishes.

Syncing another user goes through the same authed endpoint as untappd_user_checkins, so Untappd's privacy rules apply: it only works if that account is public or your friend. Otherwise the sync returns a clear error telling you to add them as a friend first.

Retention. Nothing in the cache expires: synced rows — including another user's dated check-ins, comments and venues — stay until you remove them. The file is created owner-only (directory 0700, database 0600, and older installs are tightened on open). untappd_cache_forget deletes one user's cached check-ins, distinct-beers list and sync state after a confirmation (preview shows the username and row counts); it touches only the local cache, never Untappd, and a later sync can re-fetch. Deleting the file removes everything.

A cache holds only the check-ins the account it belongs to was allowed to fetch. untappd_healthcheck reports the running version and the exact tool set (count + names + a stable hash), so you can confirm which build is serving.

Development

npm install
npm run build
npm test

License

MIT