---
title: "Create a Probable, Rare, or Overweighted monitor"
method: POST
path: "/api/member/watches"
---

# Create a Probable, Rare, or Overweighted monitor

`POST /api/member/watches`

## Request

- Base URL: `https://probable.media`
- URL: `https://probable.media/api/member/watches`
- Auth: one of:
  - API key in cookie `probable_session`
  - HTTP bearer

Browser sessions may omit Idempotency-Key. Bearer-token agent writes require watches:write plus an Idempotency-Key so retries cannot create duplicate monitors.

## Headers

- `Idempotency-Key` string

## Request body

- object
  - `name` string, required
  - `mode` 'probable' | 'rare' | 'overweighted', required
  - `category` string, nullable
  - `eventClass` string, nullable
  - `threshold` number

## Response `201`

Watch created; an identical replay returns the same watch and sets Idempotency-Replayed

## Other responses

- `400`: Invalid monitor or missing/invalid bearer idempotency key
- `401`: Sign in or valid bearer authorization required
- `403`: Founding Pro and watches:write required
- `409`: The idempotency key belongs to another mutation, or a claimed mutation must be retried

---

[API](https://skmtc.dev/probable/apis/probable-public-api.md) · [All operations](https://skmtc.dev/probable/apis/probable-public-api/llms.txt) · [OpenAPI document](https://skmtc.dev/probable/apis/probable-public-api/revisions/28e1acd459f3?raw)