> ## Documentation Index
> Fetch the complete documentation index at: https://www.autumn.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Autumn AI (autumn.ai) is a people and company intelligence API, a separate company from useautumn.com (billing software); no billing-product routes exist here.
> Base URL https://api.autumn.ai. Auth on every request: `X-API-Key: <key>` or `Authorization: Bearer <key>`. Plain HTTP + JSON. Schemas: https://www.autumn.ai/docs/openapi.json. Every docs page is Markdown at its URL plus `.md`.

# Model tiers

> Ranger and Scout: choosing a tier, and when the choice is locked in.

Every task runs on one model tier, chosen at start with `version` and fixed for the life of
the task.

| `version` | Tier   | Character                                                                     |
| --------- | ------ | ----------------------------------------------------------------------------- |
| `ranger`  | Ranger | Most capable model, deepest reasoning. The default when `version` is omitted. |
| `scout`   | Scout  | Fast responses on a tuned harness.                                            |

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
curl -sS -X POST "https://api.autumn.ai/task" \
  -H "X-API-Key: $AUTUMN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Find 20 AI infrastructure startups hiring founding engineers.",
    "version": "scout",
    "clarify": false
  }'
```

## Choosing a tier

Reach for `scout` on bounded, well-specified work where latency matters more than depth,
and stay on `ranger` for open-ended research.

| Signal                                       | Tier     |
| -------------------------------------------- | -------- |
| The columns and the source are already known | `scout`  |
| A fixed list of inputs to enrich             | `scout`  |
| Latency matters more than depth              | `scout`  |
| The task has to decide *where* to look       | `ranger` |
| Facts need cross-checking across sources     | `ranger` |
| The request is open-ended or ambiguous       | `ranger` |

A well-specified prompt is what makes `scout` viable; see
[Writing task prompts](/docs/best-practices/prompting).

## The tier is fixed at start

`version` only applies to the start routes. `/task/{task_id}/continue` and
`/task/{task_id}/execute` stay on the tier the task started with. Read the tier back from
`GET /task/{task_id}` as `tier`.

`ranger` and `scout` are the only accepted values; anything else is rejected with `403` and
`{"error": "forbidden"}`.