# Tailend > Tailend is a verified, hyper-local API of family events, classes, camps and places for people building AI agents, > assistants and apps. Listings are read from the source (the organizers' own pages wherever they exist), interpreted once into one clean shape, and > re-checked as their dates approach; anything that cannot be confirmed is withheld until it can be. It was built by > the people behind TinyJawns (https://tinyjawns.com), a family guide for Philadelphia that runs on the Tailend API. ## Metros - Philadelphia: live. - More cities open as demand builds. Vote for yours at https://tailend.dev/cities/. Philadelphia coverage as of November 2026: 3,230 active events (2,944 upcoming), 2,273 classes, 1,112 places, 24 camps, 1,283 organizations, 1,379 sources and 107 neighborhoods. ## For agents and developers - [API documentation](https://api.tailend.dev/docs): endpoints for events, classes, camps, places, organizations and metros. - [OpenAPI spec](https://api.tailend.dev/docs/openapi.json): machine-readable contract. - [Playground](https://api.tailend.dev/docs/api): try any request with sample data in the browser without a key; live requests need one. - [Status](https://api.tailend.dev/status) ## Company - [Help open your city](https://tailend.dev/cities/): where Tailend is live (Philadelphia) and how voting opens new cities. - [About Tailend](https://tailend.dev/about/): why we built Tailend: the small, local, short-lived things the rest of the internet misses, and the assistants that now need them. ## Use cases - [Use cases](https://tailend.dev/use-cases/): what people build with Tailend, with real requests. - [Family assistants and agents](https://tailend.dev/use-cases/family-assistants/): /search and /events with age, free, max_price and weekday filters, occurrences=expand for recurring series, and verified_at. - [Calendars and apps](https://tailend.dev/use-cases/calendars-and-apps/): per-day counts from /events/calendar, occurrences=expand, changed_since and /v1/changes for sync, classes; includes guides and newsletters. - [Moving and real estate](https://tailend.dev/use-cases/moving-and-real-estate/): /activity (one comparable 0 to 100 activity score for an address or point), /around (grouped results with walk times) and /nearby. ## Blog - [Tailend blog](https://tailend.dev/blog/): notes on verified local data (RSS: https://tailend.dev/blog/feed.xml). For builders: - [Transitioning off gpt-4o-mini: our benchmark results](https://tailend.dev/blog/transitioning-off-gpt-4o-mini/): GPT-6 Luna, gpt-5-nano, Gemini 3.1 Flash-Lite, DeepSeek and Gemma compared on recall, precision, latency and cost for structured extraction. - [Keep recommendations fresh as the date approaches](https://tailend.dev/blog/keep-recommendations-fresh-as-the-date-approaches/): A how-to for agent and app builders: save a listing's id instead of a copy, watch the change feed for the events you have recommended, re-check the one you are about to send a family to, and say "as of" when you report it. - [Spend your agent's reasoning on the family, not on event pages](https://tailend.dev/blog/spend-your-agents-reasoning-on-the-family-not-on-event-pages/): A how-to for agent builders: instead of paying a high-reasoning model to parse every event page and then wondering if it read it right, ask for typed fields, trim the payload, check the listing's own last-confirmed field, and save the reasoning for fitting the options to the family. - [Give your family agent the local long tail in an afternoon](https://tailend.dev/blog/give-your-family-agent-the-local-long-tail-in-an-afternoon/): A how-to for wiring a family or personal AI agent to local events, classes, camps and places with two or three tools and a short set of ground rules, so it can recommend the small, current, nearby things instead of only the famous ones. - [Why your assistant keeps suggesting the same five places](https://tailend.dev/blog/why-your-assistant-keeps-suggesting-the-same-five-places/): Assistants and big platforms keep surfacing the same well-known places because small local offerings are hard to read, so a parent (and the builder serving them) never hears about the class or market two blocks away; ranking by date, distance and age fit instead of fame changes the answer. For local organizers: - [Why your assistant keeps missing the small local places](https://tailend.dev/blog/why-assistants-cant-find-small-local-businesses/): Assistants and agents lean on what is easy to read, so small local businesses with their facts trapped in flyers and posts go unrecommended. - [Families need to know what "drop-off" means](https://tailend.dev/blog/what-drop-off-means/): Supervision and care details (who can leave, who must stay, what to bring) often live on a policy page instead of the listing where a parent is deciding. - [The details that make a listing usable](https://tailend.dev/blog/the-details-that-make-a-listing-usable/): A clear summary, a real contact route, and practical visit information help someone decide and act before they move on to the next tab. - [See what's happening in your neighborhood market this month](https://tailend.dev/blog/see-whats-happening-in-your-neighborhood-market-this-month/): A how-to for a local business owner (with a developer friend or an AI assistant) to answer four practical questions about the neighborhood market with a handful of real API requests: what is on my slot, what similar classes cost, who else is here, and where the clashes are. - [The seven facts almost every event listing leaves out](https://tailend.dev/blog/the-facts-every-event-listing-leaves-out/): The specific facts listings routinely omit and why each one costs trust and recommendations. - [Posting only on social is quietly hiding you](https://tailend.dev/blog/posting-only-on-social-is-quietly-hiding-you/): Social posts reach followers but give search and AI agents nothing stable to find; keep posting and give every event a plain page. - [Small businesses can't see their own market](https://tailend.dev/blog/small-businesses-cant-see-their-own-market/): Local operators need a shared, trustworthy picture of nearby activity to make small decisions well. - [Why your events don't show up](https://tailend.dev/blog/why-your-events-dont-show-up/): A few practical publishing habits make local events easier for people and local tools to find. - [Your local market is public, but you can't read it](https://tailend.dev/blog/your-local-market-is-public-but-you-cant-read-it/): Everything an owner needs to understand the local market (what else is on, what it costs, who is new) is already public, but it sits on flyers, calendar widgets, booking portals and social posts that no one can read side by side. Data quality: - [The week-of problem](https://tailend.dev/blog/the-week-of-problem/): An event confirmed last month is not safe to recommend today, because dates move, sessions fill, rain dates kick in and things get cancelled in the final days; freshness should be measured where the decision happens, close to the event, and a listing should say honestly when it was last confirmed. - [A weekly class should stay visible without taking over the calendar](https://tailend.dev/blog/a-weekly-class-should-stay-visible-without-taking-over-the-calendar/): Treating a recurring class as one listing shown by its next date keeps both regulars and new visitors oriented, instead of flooding the calendar or vanishing after the first week. - [A missing page is not always a cancelled event](https://tailend.dev/blog/a-missing-page-is-not-always-a-cancelled-event/): A broken link and a real cancellation look the same from the outside; we check which one it is before taking anything off a local calendar. - [A place is more than a pin on a map](https://tailend.dev/blog/a-place-is-more-than-a-pin-on-a-map/): Hours and admission details for a place are scarce, changeable facts. They deserve real evidence rather than an optimistic default, even when that means saying we don't know yet. - [An address can be almost right and still be wrong](https://tailend.dev/blog/an-address-can-be-almost-right-and-still-be-wrong/): A location match that's close but not exact can send a parent, a customer, or a delivery route to the wrong door; careful matching is worth the extra step. - [A date is a promise, not a guess](https://tailend.dev/blog/a-date-is-a-promise-not-a-guess/): An invented or unclear event date can send a family out for nothing and quietly multiply into duplicate rows on a builder's calendar; a date should be published only when something actually says it, not assumed. - [A wrong merge costs more than a missed duplicate](https://tailend.dev/blog/a-wrong-merge-costs-more-than-a-missed-duplicate/): Local data should treat uncertain identity as a question for review, not an excuse to combine different listings. - [Freshness is the product](https://tailend.dev/blog/freshness-is-the-product/): "Confirmed recently, close to the event" is a better freshness signal for local data than "checked on a routine schedule." Company: - [What running a local family guide taught us about local data](https://tailend.dev/blog/what-running-a-local-family-guide-taught-us-about-local-data/): Tailend grew out of TinyJawns, a family guide in Philadelphia; four problems kept coming back (messy sources, the cost of knowing a page was read correctly, things changing as the date approaches, and the long tail getting lost), and Tailend is built around each of them. ## Example GET https://api.tailend.dev/v1/philadelphia/events?from=2026-10-17&to=2026-10-18&age=4 Header: X-API-Key: Useful filters on that endpoint include age, free, neighborhood, category, q (keyword search), occurrences=expand (one row per session of a recurring series) and changed_since (incremental sync). ## Pricing Full details: https://tailend.dev/pricing/ - Free: 2,000 credits (at most 500 a day, expire after 60 days), 1 key, 30 requests a minute, no card. - Pay as you go: $1 per 1,000 credits, prepaid from $10, credits never expire, optional credit limits per key. - Sync (pilot, not yet generally available): $199 per city per month; includes 100,000 credits per city per month (no rollover), change feed, bulk export; overage $1 per 1,000 only if opted in. - 1 credit = 1 record returned. Empty results, errors and 304 Not Modified are free. - Add-ons on paid keys: include=source +2 and include=forecast +2 per record; include=related +1 per related record; history 5, trends 25 and insights 5 (beta) per request; calendar 1 per request. - Data-use terms (caching and redistribution) will be published before launch. Planned caching: 24 hours, 7 days on Sync. ## Access Requests need an API key (X-API-Key header). Keys are issued on request: https://tailend.dev/#request . Quickstart: https://api.tailend.dev/docs/quickstart To ask for a new city, or to join the waitlist for Spaces by Tailend (local-data insight for studios, venues and rec programs, not yet available), use the form at https://tailend.dev/#request.