# Making requests

> Every call to the MISSIN API is a persisted operation: send its name, its hash and your variables, never a query document of your own.

## The endpoint

```http
POST https://api.missin.co.uk/graphql/v1
```

## Persisted operations only

The API runs persisted operations: GraphQL documents the server already holds, each named by the SHA-256 hash of its text. A request names the operation and its hash and sends variables; it never sends a query document. A hash the server does not hold is refused.

```json
{
  "operationName": "CampaignsList",
  "variables": {
    "first": 20
  },
  "extensions": {
    "persistedQuery": {
      "version": 1,
      "sha256Hash": "cc4c4616f86feca4fafac98d357af608114b690240d58999fe247adae9c52df6"
    }
  }
}
```

Every operation a key can run, with its hash, its variables and a request to copy, is in the [API reference](https://developer.missin.co.uk/reference.md).

## A first request

Save the body above as `request.json`, then:

```bash
curl https://api.missin.co.uk/graphql/v1 \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d @request.json
```

The response is standard GraphQL: `data` with the result, and `errors` when something went wrong (see [Errors](https://developer.missin.co.uk/get-started/errors.md)).

## What a key can run

A key can run the operations in the [API reference](https://developer.missin.co.uk/reference.md), and nothing else. Each page says what the operation needs: Read operations read your workspace and run with the key's own database role, so the database itself decides what comes back and a key never sees another workspace. Write operations change workspace data, and Admin operations also change settings and connections.

An operation the reference does not list is refused before it runs: with `operation_not_public` when it is not open to keys, and with `insufficient_access` when the key's level is below what the operation needs. An assistant can reach the same operations through the [MISSIN MCP server](https://developer.missin.co.uk/mcp/connect-claude.md).

Source: https://developer.missin.co.uk/get-started/making-requests