---
title: "Create Chunk Relation"
method: POST
path: "/v3/collections/{collection_name}/chunks/{chunk_id}/relations"
tags: ["file-search"]
---

# Create Chunk Relation

`POST /v3/collections/{collection_name}/chunks/{chunk_id}/relations`

Create a typed relation from one chunk to another chunk.

## Path parameters

- `collection_name` string, required
- `chunk_id` string, required

## Request body

- CreateChunkRelationRequestV3
  - `target_chunk_id` string, required
  - `target_document_id` string, nullable
  - `relation_type` string, required
  - `metadata` CreateChunkRelationRequestV3Metadata

## Response `201`

Successful Response

- ChunkRelationResponseV3
  - `relation` ChunkRelationFromV3, required
    - `relation_id` string, required
    - `source_chunk_id` string, required
    - `target_chunk_id` string, required
    - `target_document_id` string, nullable
    - `target_status` 'found' | 'missing' | 'unknown'
    - `relation_type` string, required
    - `metadata` ChunkRelationFromV3Metadata
    - `created_at` string, nullable
    - `updated_at` string, nullable

## Other responses

- `400` — Source and target chunk IDs must differ.
- `401` — Missing or invalid authentication.
- `403` — API key cannot write to this collection.
- `404` — Collection not found.

---

[API](https://skmtc.dev/runcaptain/apis/api-reference.md) · [All operations](https://skmtc.dev/runcaptain/apis/api-reference/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/runcaptain/api-reference/revisions/fe4649e3f4aa/schema)