# deriveConfidence

**Kind:** Function

**Source:** [`atloria-monorepo/libs/parser-core/src/techdocs/grounded-ask.ts`](https://github.com/sherkety/atloria/blob/main/atloria-monorepo/libs/parser-core/src/techdocs/grounded-ask.ts#L76)

Derive a confidence band from what retrieval actually returned and what the model
actually grounded in — two signals already produced upstream, so no extra model call:
  • retrieval strength — the top hit's similarity (keyword-exact = 1, semantic = cosine)
  • grounding — how many retrieved sources the answer cited (validateCitations)

A cited answer over strong, corroborated retrieval is 'high'; a cited answer over a
single decent source is 'medium'; cited-but-weak is 'low'. When the model cited NOTHING
and retrieval was weak, there is no honest answer to give → 'insufficient' (the caller
then substitutes INSUFFICIENT_EVIDENCE_ANSWER rather than surface a fabrication).

## Signature

```ts
function deriveConfidence(sources: DocSearchHit[], citations: string[], thresholds: { strong: number; medium: number }): RagConfidence
```

## Parameters

| Name | Type |
|---|---|
| `sources` | `DocSearchHit[]` |
| `citations` | `string[]` |
| `thresholds` | `{ strong: number; medium: number }` |

**Returns:** `RagConfidence`