GET/v1/changesall plans

List changes

Returns every public-field change to a listing since since, oldest first. To sync incrementally, keep the last version_id you saw and pass it as cursor. Removals (status leaving published, is_active becoming false, or a hard delete) appear here even though the resource itself returns 404.

Each item exposes only the change time, a closed change kind, and allowlisted public field names. Values, actors, pipeline attributes, and rows that touch only internal fields are never returned. Read freshness from source.crawled_at (include=source) on the resource.

Sync is in a pilot; the change feed needs a Sync plan.

Try this requestRun it with sample data, no key needed. Paste a key to run it live.

Example request

curl -sS \
  -H "X-API-Key: $TAILEND_API_KEY" \
  "https://api.tailend.dev/v1/changes?since=2026-10-01T00%3A00%3A00Z"

Example response · 200

{
  "data": [
    {
      "version_id": 18231,
      "listing_id": "2f3c9d4e-3d2b-4b7d-9a3e-1b2c3d4e5f60",
      "slug": "storytime-in-the-park-2026-09-12",
      "type": "event",
      "metro": "philadelphia",
      "changed_at": "2026-09-10T06:12:05Z",
      "kind": "date_changed",
      "fields": [
        "starts_at"
      ]
    }
  ],
  "meta": {
    "limit": 1,
    "count": 1,
    "has_more": false
  }
}

API key Remember for this tab

Try any request with sample data, no key needed. Available on every plan.

sincestring (date-time)requiredquery

Return changes with changed_at strictly after this instant.

Optional parameters (4)

metrostringoptionalquery

Restrict to one metro slug (must be in the key's scope).

typestringoptionalquery

Restrict to one listing type.

cursorstringoptionalquery

This is not an opaque cursor: pass back the decimal string returned by meta.next_cursor, and the feed resumes strictly after it.

limitintegeroptionalquery

Response

A 200 returns application/json with these fields.

dataarray of Changealways present
- version_idinteger (int64)always present
  Monotonic — use as the cursor.
- listing_idstring (uuid)always present
- slugstring · nullable
  The listing's slug, so a removal can be turned into the path to revalidate. Read from the listing when it still exists; for a row that is gone, from what the version row captured — a hard delete records every contract field the row had. null only when neither has one.
- typestringalways present
  The listing's type. ongoing rows are served only on /v1/changes today.
  eventclasscampplaceongoing
- metrostring · nullable
  Metro slug (captured on the version row, so deletes keep it).
- changed_atstring (date-time)always present
- kindstringalways present
  createdupdateddate_changedprice_changedlocation_changedarchivedrestored
- fieldsarray of stringalways present
  Sorted names of changed public fields. Internal and unknown fields are omitted.
  admissionagesall_daybirthday_partiescategoriesdescriptionends_atends_localends_onhas_timehoursimage_urlimagesis_overnightis_recurringis_sold_outis_specialtyis_travellocationmembershipnameorganizationplacepricepricing_unitprogramrecurrence_descriptionregistrationregistration_requiredregistration_urlrrulescheduleseasonsectionssessionsslugstart_timestarts_atstarts_localstarts_onstatustermticket_urltimezonetuitiontype_hinttype_hint_notesyear
metaobjectalways present
- sincestring (date-time)
- metrostring · nullable
- limitintegeralways present
- countintegeralways present
- has_morebooleanalways present
- next_cursorstring · nullable
  The position to pass as cursor on the next request. It can advance even when data is empty.
- generated_atstring (date-time)

Status codes

200
A page of changes
400
Malformed or contradictory parameters (lat without lng, to before from, unknown category), or a cursor this API did not issue for this exact request — replayed from another endpoint, resource, metro or filter set, hand-crafted, or altered.
401
Missing, unknown or revoked X-API-Key. Also returned when the key record itself does not validate — the server fails closed and logs why rather than assuming anything about a row it cannot vouch for, and when the value is not shaped like a key (tl_ + 8 hex + _ + 48 hex). The message is invalid API key; the reason is not disclosed. The one exception is a credential shaped like a different kind of token, whose 401 explains it is the wrong credential for /v1 rather than repeating the generic message.
403
Two different reasons share this status. Read error.code.
Show more
forbidden — the key is valid but its scopes exclude this metro or resource type, or the client is inactive. Returned when the caller named the metro or type it was refused — in the path, or in ?metro=. Where the caller supplied only an identifier, an out-of-scope resource is a 404 instead; see NotFound.

include_not_permitted (endpoints that take include= only) — the key is valid and in scope, but is not entitled to a requested include= add-on (details.include names it). Add include_mode=lenient to get a 200 without the block instead of this. See Shaping responses.
405
The path exists; the method does not. Every route on this API is a read, so Allow is always GET, HEAD, OPTIONS. A method on a path that does not exist is a 404 instead — 405 is only ever sent where there is a target resource to refuse.
429
A limit was reached. Branch on error.code, not on the status — two different limits share this status:
Show more
- rate_limited — the per-minute rate. Retry-After is seconds, and retrying after it succeeds.
- rate_limited can also mean address lookups are temporarily unavailable. The response explains the condition and provides Retry-After; callers that already have coordinates can send lat/lng instead.
- quota_exceeded — the monthly allowance, or a client's hard cap. Retry-After points at the start of the next UTC month and can therefore be very large; details carries plan, monthly_limit, used and resets_at. Backing off will not help before the reset — the plan has to change. This is a 429; 402 is reserved.
500
A bug on our side. The message is always the constant internal error; details are never included in the body. Retry once with backoff, then contact support with the request_id.
501
This endpoint or feature is not available and will not become available without a configuration change — for ?address=, this means no geocoder is configured.
Show more
Nothing is failing, so do not retry and do not back off: there is no Retry-After, and the answer will not change inside any timeout you set. Treat the feature as switched off, disable it in your UI, and use the alternative the message names where there is one (lat/lng instead of address).

The message is a constant per endpoint family and names no internal object. Include the request_id when contacting support.
503
A transient outage: a dependency could not be reached or did not answer in time. This is the 5xx worth retrying — Retry-After says how long, and the same request is expected to succeed afterwards.

Like every other error here, the message names no internal detail.

Every error uses the same envelope; branch on error.code. See Errors.

Ctrl Enter to send

Request

GEThttps://api.tailend.dev/v1/changes?since=2026-10-01T00%3A00%3A00Z

curl -sS \
  -H "X-API-Key: $TAILEND_API_KEY" \
  "https://api.tailend.dev/v1/changes?since=2026-10-01T00%3A00%3A00Z"

const res = await fetch("https://api.tailend.dev/v1/changes?since=2026-10-01T00%3A00%3A00Z", {
  headers: { 'X-API-Key': '$TAILEND_API_KEY' },
});
const body = await res.json();
console.log(res.status, body);

import os
import requests

response = requests.get(
    "https://api.tailend.dev/v1/changes?since=2026-10-01T00%3A00%3A00Z",
    headers={'X-API-Key': os.environ['TAILEND_API_KEY']},
)
response.raise_for_status()
print(response.json())

ResponseSample

Showing sample data. Paste a key to run it live. Get a key

A page of changes

{
  "data": [
    {
      "version_id": 18231,
      "listing_id": "2f3c9d4e-3d2b-4b7d-9a3e-1b2c3d4e5f60",
      "slug": "storytime-in-the-park-2026-09-12",
      "type": "event",
      "metro": "philadelphia",
      "changed_at": "2026-09-10T06:12:05Z",
      "kind": "date_changed",
      "fields": [
        "starts_at"
      ]
    }
  ],
  "meta": {
    "limit": 1,
    "count": 1,
    "has_more": false
  }
}

Malformed or contradictory parameters (lat without lng, to before from, unknown category), or a cursor this API did not issue for this exact request — replayed from another endpoint, resource, metro or filter set, hand-crafted, or altered.

{
  "error": {
    "code": "bad_request",
    "message": "radius_m: must be at least 100",
    "details": {
      "param": "radius_m"
    },
    "request_id": "req_dfbc3295a8382b05"
  }
}

Missing, unknown or revoked X-API-Key.

{
  "error": {
    "code": "unauthorized",
    "message": "missing X-API-Key header",
    "request_id": "req_90e63908273f6bff"
  }
}

Two different reasons share this status.

{
  "error": {
    "code": "forbidden",
    "message": "key is not scoped to metro 'boston'",
    "details": {
      "metros": [
        "philadelphia"
      ]
    },
    "request_id": "req_9e7a750acef48ab2"
  }
}

The path exists; the method does not.

{
  "error": {
    "code": "method_not_allowed",
    "message": "POST is not allowed on this path; this API is read-only",
    "details": {
      "allow": [
        "GET",
        "HEAD",
        "OPTIONS"
      ]
    },
    "request_id": "req_01J9Z3"
  }
}

A limit was reached.

{
  "error": {
    "code": "rate_limited",
    "message": "3 requests per minute exceeded",
    "request_id": "req_06bfd3c2d5e8aa9f"
  }
}

A bug on our side.

{
  "error": {
    "code": "internal",
    "message": "internal error",
    "request_id": "req_01J9Z3"
  }
}

This endpoint or feature is not available and will not become available without a configuration change — for ?address=, this means no geocoder is configured.

{
  "error": {
    "code": "not_implemented",
    "message": "this endpoint is not enabled on this deployment; it is not a fault and retrying will not help",
    "request_id": "req_01J9Z3"
  }
}

A transient outage: a dependency could not be reached or did not answer in time.

{
  "error": {
    "code": "unavailable",
    "message": "the service is temporarily unable to serve this request; retry after the interval in Retry-After",
    "request_id": "req_01J9Z3"
  }
}