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

# IBF Engine

> The inference infrastructure behind the IBF API.

The IBF (Interaction Behaviour Framework) Engine is the hosted deployment of the SGM that powers the API at `ibf.blankstate.ai`. It handles preprocessing, Protocol lookup, inference, metamarker extraction, and response assembly.

## Request lifecycle

1. Content arrives at the `/sense` endpoint with a Protocol or Blueprint identifier.
2. The Engine preprocesses input for the declared modality (transcription for audio/video; segmentation for text).
3. The SGM runs the projection defined by the Protocol.
4. Metamarkers are extracted. Activations below the `fidelityThreshold` are suppressed.
5. Signatures are updated (if `actantId` is present and Signature tracking is enabled).
6. Response is assembled and returned. ICS are accrued for the activated nuances.

## Latency

Real-time on CPU. See [blankstate.ai/sgm](https://blankstate.ai/sgm) for reference measurements.

## Endpoints

Full reference: [API Reference](/api-reference).

| Endpoint                     | Description                                 |
| ---------------------------- | ------------------------------------------- |
| `POST /sense`                | Run a Protocol or Blueprint against content |
| `GET /protocols`             | List available Protocols                    |
| `GET /protocols/{id}`        | Protocol definition                         |
| `GET /signatures/{actantId}` | Retrieve a Signature                        |
| `GET /usage`                 | ICS usage and quota                         |