---
title: "Hashing and source identity"
manual: "AI Assistant"
version: "main"
source: "Developers/Architecture/HashingAndSourceIdentity.rst"
rendered: "2026-10-03T14:54:45+00:00"
---

# Hashing and source identity {#hashing-source-identity}

Source identity and change detection must be separate.

## Source hash {#source-hash}

The source hash identifies the source object. It should be derived from stable
source information, such as:

```text
source_type | source_identifier | language
```

It should not include content, collection or vector store information.

## Content hash {#content-hash}

The content hash detects changes. It can include normalized text and relevant
metadata that should trigger re-indexing.

## Storage scope {#storage-scope}

The same source can be indexed into multiple vector stores or collections. The
indexing state must therefore track vector store connection and collection
separately from the source hash.

## Vector document identity {#vector-document-identity}

Vector document ids should be stable per source and chunk. The vector database
may require UUID-compatible identifiers. Do not use arbitrary SHA-1 hex strings
as ids for vector stores that require UUIDs or integers.