---
title: "Write Run Blob"
method: POST
path: "/api/v1/runs/{id}/blobs"
tags: ["Run Internals"]
---

# Write Run Blob

`POST /api/v1/runs/{id}/blobs`

Writes an opaque binary blob and returns its content-addressed blob hash.

## Path parameters

- `id` string, required

## Response `200`

Blob written

- WriteBlobResponse — Content-addressed hash of a stored blob.
  - `hash` string, required — Content-addressed SHA-256 hash of a stored blob. Hex input is case-insensitive; Fabro emits the canonical lowercase form.

## Other responses

- `404` — Run not found

---

[API](https://skmtc.net/fabro-sh/apis/fabro-run-api.md) · [All operations](https://skmtc.net/fabro-sh/apis/fabro-run-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/fabro-sh/fabro-run-api/revisions/52f1d8aaf083/schema)