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

# Aria Compute PIN API: Post-Training & Evaluation

> Overview of the Aria Compute PIN API for fine-tuning, LoRA, RL, evaluation, and model export. Base URL, versioning, authentication, and quick links.

Aria Compute PIN is the end-side post-training service for fine-tuning, LoRA adaptation, reinforcement learning, evaluation, and model export. The PIN API exposes these capabilities over HTTP at base URL `http://<pin-host>:8001` under the `/v1` path prefix.

All `/v1/*` routes require a Bearer API key passed in the `Authorization` header, except for public routes such as `/health`, `/version`, `/v1/auth/login`, and `/v1/auth/register`. Routes under `/v1/agent/*` use a node-agent HMAC token scheme and are intended for internal agent callbacks. Error responses follow a standard envelope:

```json theme={null}
{
  "error": "string",
  "detail?": "string"
}
```

Common status codes include `400` for validation errors, `401` for unauthorized requests, `404` for missing resources, and `500` for internal errors.

<CardGroup cols={2}>
  <Card title="Authentication" icon="key" href="/api-reference/pin/authentication">
    Learn how to authenticate with Bearer API keys and node-agent HMAC tokens.
  </Card>

  <Card title="Create a Job" icon="plus" href="/api-reference/pin/jobs/create">
    Submit fine-tuning, LoRA, or RL jobs through the PIN API.
  </Card>

  <Card title="List Models" icon="list" href="/api-reference/pin/models/list">
    Browse available base models and exported checkpoints.
  </Card>

  <Card title="Billing Summary" icon="money-bill" href="/api-reference/pin/billing/summary">
    Retrieve usage and billing summaries for your organization.
  </Card>
</CardGroup>


## Related topics

- [Create Evaluation](/api-reference/pin/evaluations/create.md)
- [Get Evaluation](/api-reference/pin/evaluations/get.md)
- [List Evaluations](/api-reference/pin/evaluations/list.md)
- [Create Training Job with PIN API](/api-reference/pin/jobs/create.md)
- [POST /v1/auth/register: PIN User Registration](/api-reference/pin/auth/register.md)