---
title: "Upload a chunk of data"
method: PATCH
path: "/v2/{name}/blobs/{ref}/{session_id}"
tags: ["oci"]
---

# Upload a chunk of data

`PATCH /v2/{name}/blobs/{ref}/{session_id}`

Appends a chunk of data to an in-progress upload session. This is the recommended approach for large blobs, as each chunk is stored immediately rather than buffering the entire blob in memory.

Clients can call this endpoint multiple times to upload a blob in pieces, then call `PUT /v2/{name}/blobs/uploads/{session_id}?digest=...` to complete the upload.

The `Content-Range` header is optional but recommended - if provided, the server validates that the chunk starts at the expected offset.

## Path parameters

- `name` string, required
- `ref` string, required
- `session_id` string, required

## Response `default`

---

[API](https://skmtc.net/bencherdev/apis/bencher-api.md) · [All operations](https://skmtc.net/bencherdev/apis/bencher-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/bencherdev/bencher-api/revisions/84086e99e6cd/schema)