storage & assets

Upload and reuse assets

Upload existing images, audio, and video, then reference them from campaigns and creative jobs.

10 minutes

Beginner

Creators

Remote execution

What You Will Finish With

Your source material appears in Media and can be reused without uploading duplicate copies for every campaign.

1
Check writable storage
Open Storage and confirm one destination is ACTIVE and selected for writes.
2
Create an upload slot
Upload from Media or ask an authorized agent to call media_create_upload. Postward returns a short-lived signed URL and the asset id you will reference later.
3
Upload bytes directly
The browser or agent sends the file to storage; large media does not pass through the Next.js process.
4
Finalize
Finalize the slot so Postward verifies size and records the durable logical asset.
5
Attach by reference
Campaign source Markdown cites the media-library asset as asset://<assetId>; cite the same id when asking the agent to generate or edit content.

Where to go next

Part of Scale content production. Finish the journey in order for the full picture.

Ask my agent

Copy a ready prompt for this tutorial and paste it into any agent connected to Postward.

Preview the prompt

Follow the Postward tutorial "Upload and reuse assets".

Outcome: Your source material appears in Media and can be reused without uploading duplicate copies for every campaign.
Prerequisites to verify first: Writable workspace storage; An image, audio file, or video.

Steps:
1. Check writable storage: Open Storage and confirm one destination is ACTIVE and selected for writes.
2. Create an upload slot: Upload from Media or ask an authorized agent to call media_create_upload. Postward returns a short-lived signed URL and the asset id you will reference later.
3. Upload bytes directly: The browser or agent sends the file to storage; large media does not pass through the Next.js process.
4. Finalize: Finalize the slot so Postward verifies size and records the durable logical asset.
5. Attach by reference: Campaign source Markdown cites the media-library asset as asset://<assetId>; cite the same id when asking the agent to generate or edit content.

First inspect my environment and existing configuration, and verify each prerequisite before acting.
Follow the current Postward documentation rather than assuming tool names.
Do not replace unrelated configuration.
Verify the result and report exactly what changed.

Prerequisites

Writable workspace storage
An image, audio file, or video

Works With

Studio
Postward MCP