---
title: "Create an asset reference from an existing hash"
method: POST
path: "/api/assets/from-hash"
tags: ["assets"]
---

# Create an asset reference from an existing hash

`POST /api/assets/from-hash`

Registers a new asset that references existing content by hash, without re-uploading the bytes.

## Request body

- object
  - `hash` string, required — Blake3 hash of existing content
  - `name` string, required — Display name
  - `tags` string[]
  - `user_metadata` object

## Response `201`

Asset created from hash

- AssetCreated — A registered asset — an input/output file tracked in the asset database with content hash and metadata.
  - `id` string, uuid, required — Unique identifier for the asset
  - `name` string, required — Name of the asset file
  - `asset_hash` string — Blake3 hash of the asset content
  - `size` integer, required — Size of the asset in bytes
  - `mime_type` string — MIME type of the asset
  - `tags` string[] — Tags associated with the asset
  - `user_metadata` object — Custom user metadata
  - `metadata` object — System-managed metadata (read-only)
  - `preview_url` string, uri — URL for asset preview/thumbnail
  - `preview_id` string, uuid — ID of the preview asset if available
  - `prompt_id` string, uuid — ID of the prompt that created this asset
  - `created_at` string, date-time, required
  - `updated_at` string, date-time, required
  - `last_access_time` string, date-time
  - `is_immutable` boolean — Whether this asset is immutable
  - `created_new` boolean, required — Whether this was a new creation (true) or returned existing (false)

## Changes

- **2026-04-24** `a66055fa384e` — 2 breaking, 6 warning, 12 info
  - the request property `name` became required
  - removed the success response with the status `200`
  - removed the request property `mime_type`
  - removed the optional property `allOf[#/components/schemas/Asset]/display_name` from the response with the `201` status
  - …16 more

[Change history](https://skmtc.dev/comfy-org/apis/comfyui-api/changes/api/assets/from-hash/post.md)

---

[API](https://skmtc.dev/comfy-org/apis/comfyui-api.md) · [All operations](https://skmtc.dev/comfy-org/apis/comfyui-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/comfy-org/comfyui-api/revisions/a66055fa384e/schema)