---
title: "Create a segment"
method: POST
path: "/api/v1/segments"
tags: ["Segments"]
---

# Create a segment

`POST /api/v1/segments`

## Request

- Base URL: `https://api.sendly.now`
- URL: `https://api.sendly.now/api/v1/segments`
- Auth: one of:
  - HTTP bearer
  - API key in cookie `better-auth.session_token`
  - OAuth 2 (authorization code, authorization URL `https://app.sendly.now/api/auth/oauth2/authorize`, token URL `https://app.sendly.now/api/auth/oauth2/token`, scopes: `segments:write`)

Create a `DYNAMIC` segment (a saved `condition`, re-evaluated against contacts on every read) or a `STATIC` one (an explicitly managed membership list). `type` is fixed at creation — it decides how membership is computed, so it cannot be changed later.

A `DYNAMIC` segment requires a `condition`, which is validated and evaluated during the request: the response's `member_count` tells you immediately how many contacts the filter actually matches.

Requires the `segments:write` scope — Create, edit, and delete your segments.

## Request body

- SegmentV1Create: Body for POST /api/v1/segments. `condition` is required when `type` is `DYNAMIC`.
  - `condition` FilterConditionV1: A filter condition: one or more groups combined with `logic`.
    - `groups` FilterGroupV1[], required
      - `conditions` FilterConditionV1 (recursive)
      - `filters` SegmentFilterV1[], required
        - `field` string, required
        - `operator` 'equals' | 'notEquals' | 'contains' | 'notContains' | 'greaterThan' | 'lessThan' | 'greaterThanOrEqual' | 'lessThanOrEqual' | 'exists' | 'notExists' | 'within' | 'olderThan' | 'triggered' | 'triggeredWithin' | 'triggeredOlderThan' | 'notTriggered' | 'notTriggeredWithin' | 'isMemberOf', required
        - `unit` 'days' | 'hours' | 'minutes'
        - `value` unknown
    - `logic` 'AND' | 'OR', required
  - `description` string
  - `name` string, required
  - `track_membership` boolean: Emit segment entry/exit events as contacts move in and out. Off by default — it costs a membership write per transition.
  - `type` 'DYNAMIC' | 'STATIC'

## Response `201`

Segment created

- SegmentV1: A segment as exposed on the v1 API.
  - `condition` FilterConditionV1, required: A filter condition: one or more groups combined with `logic`.
    - `groups` FilterGroupV1[], required
      - `conditions` FilterConditionV1 (recursive)
      - `filters` SegmentFilterV1[], required
        - `field` string, required
        - `operator` 'equals' | 'notEquals' | 'contains' | 'notContains' | 'greaterThan' | 'lessThan' | 'greaterThanOrEqual' | 'lessThanOrEqual' | 'exists' | 'notExists' | 'within' | 'olderThan' | 'triggered' | 'triggeredWithin' | 'triggeredOlderThan' | 'notTriggered' | 'notTriggeredWithin' | 'isMemberOf', required
        - `unit` 'days' | 'hours' | 'minutes'
        - `value` unknown
    - `logic` 'AND' | 'OR', required
  - `created_at` string, date-time, required
  - `description` string, nullable, required
  - `id` string, uuid, required
  - `member_count` integer, required
  - `name` string, required
  - `track_membership` boolean, required
  - `type` 'DYNAMIC' | 'STATIC', required
  - `updated_at` string, date-time, required

## Other responses

- `400`: `validation_error` — a `DYNAMIC` segment was submitted without a `condition`, or the `condition` filters on a field contacts cannot be filtered on or uses an operator that field does not have.
- `401`: `invalid_api_key` or `invalid_session` — missing or invalid credentials.
- `403`: `scope_missing`, `project_access_denied`, or `project_disabled`.
- `422`: `validation_error` — query, path, or body parameters did not match the schema.
- `429`: `rate_limited` — see `Retry-After` and the `RateLimit` headers.
- `500`: `internal_error`.

---

[API](https://skmtc.dev/sendly/apis/sendly-api.md) · [All operations](https://skmtc.dev/sendly/apis/sendly-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sendly/apis/sendly-api/revisions/ce7cfb7f7c7e?raw)