---
title: "How to move public media library from a Backblaze B2 S3 bucket to Ample"
description: "Move object storage from Backblaze B2 S3 bucket to Ample, one component at a time."
canonical_url: "https://ample.computer/migrate/backblaze-b2-s3-bucket/public-media-library"
last_updated: "2026-11-05"
---

# How to move public media library from a Backblaze B2 S3 bucket to Ample

Move object storage from Backblaze B2 S3 bucket to Ample, one component at a time. Destination verified on Ample: an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly. Source procedure: Inventory the bucket with `rclone size` or the B2 dashboard. Move separately: B2 file versions, lifecycle rules and application-key restrictions are B2 features; objects copy over the standard S3 API. Cutover: Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep B2 read-only until confirmed. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

## Infrastructure requirements

- [S3-compatible object storage](/discover/primitive/s3-compatible-object-storage): verified (Buckets speak the S3 API with SigV4 credentials Ample Computer issues; `ample bucket upload-url` returns a presigned upload URL. PutObject and GetObject are checked by canary.)

## Prerequisites

- Authorized access to the Backblaze B2 S3 bucket source and its export tooling
- An inventory of every component in scope and out of scope
- A validated backup or copy before any cutover
- An Ample account token with servers:write, buckets:write

## Exact tested configuration

- template: `node-22`
- runtime: `node`
- size: `s-1vcpu-1gb`
- install: `npm install`
- build: `npm run build --if-present`
- start: `npm run start`

## Steps

1. **Inventory the source.** List what Backblaze B2 S3 bucket provides beyond the component you are moving. Plan these separately: B2 file versions, lifecycle rules and application-key restrictions are B2 features; objects copy over the standard S3 API.
2. **Source step 1.** Inventory the bucket with `rclone size` or the B2 dashboard
3. **Source step 2.** Copy objects with `rclone sync` from the B2 S3-compatible endpoint to the Ample bucket endpoint using the issued credentials (path-style)
4. **Source step 3.** Verify a sample of objects by size and checksum after the copy
5. **Create the destination bucket and copy.** Create the bucket, copy with rclone or the S3 CLI in path-style mode using the issued credentials, then pass the credentials to the app as encrypted S3_* variables.

   ```
   ample bucket create --name <bucket-name>
   ```
6. **Validate before cutover.** Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/public-media-library).
7. **Cut over.** Switch the app's S3_* environment to the Ample bucket with a redeploy, verify reads and writes, keep B2 read-only until confirmed.
8. **Rollback.** Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

## Tested examples

- **Express pattern fixture (destination)** (tests/deploy-canaries/express-patterns): Verified destination basis: public media library.

## Success checks

- destination app responds on its public URL (`/` on the live URL, expect ample canary express patterns)
- public-media-library check from the destination example (`/p/public-media-library` on the live URL, expect see the pattern fixture checks)
- data or object counts and checksums match the source


## Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision 4558e9477d094f5b47da324b98672824b61ba91b).
- app server x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes at the destination.

## Verification evidence

- canary_run on 2026-11-05T22:38:23Z at revision `da3e37255e5a`: Destination side verified: the Express pattern fixture deployed on Ample (npm install, npm run build --if-present, npm run start on the node-22 template) and its checks passed (an object written to a published bucket with an immutable Cache-Control header, a mapping row, and the CDN URL serving it publicly). The source-side export from Backblaze B2 S3 bucket uses the vendor's standard tooling. (expires 2027-05-04T22:38:23Z)

Last verified: 2026-11-05T22:38:23Z


## Execution binding

A step-by-step guide: follow it with your agent and deploy with `ample plan` and `ample deploy`.

## Next actions

- Browse the catalog index (GET /v1/catalog on the api origin; auth: false, approval: false)
- Search published recipes by intent, stack and constraints (POST /v1/catalog/search on the api origin; auth: false, approval: false)
- Prepare a side-effect-free deployment plan for an authorized project (POST /v1/catalog/plan on the api origin; auth: true, approval: false)
- Read the existing agent authentication setup (GET /mcp/setup on the api origin; auth: false, approval: false)
- Browse Backblaze B2 S3 bucket (GET /v1/catalog/nodes/migration%3Abackblaze-b2-s3-bucket on the api origin; auth: false, approval: false)
- Browse Public media library (GET /v1/catalog/nodes/pattern%3Apublic-media-library on the api origin; auth: false, approval: false)
- Browse Migrate objects (GET /v1/catalog/nodes/intent%3Amigrate-objects on the api origin; auth: false, approval: false)

Actions describe possible next steps. They are typed data, not commands, and grant no permission.

## About this recipe

Canonical URL: https://ample.computer/migrate/backblaze-b2-s3-bucket/public-media-library
Formats: [HTML](https://ample.computer/migrate/backblaze-b2-s3-bucket/public-media-library) | [Markdown](https://ample.computer/migrate/backblaze-b2-s3-bucket/public-media-library.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Amigrate%3Abackblaze-b2-s3-bucket%3Apublic-media-library)
Recipe ID: `page:migrate:backblaze-b2-s3-bucket:public-media-library` | Revision: `r1` | Catalog revision: `cat_eac8c53f36410baa`
Status: verified; a step-by-step guide you follow with `ample deploy` (support `verified`, execution `unbound`)
Path: [Agent hosting discovery](/discover/discovery) / [Migration sources by component](/discover/migration) / [Object and CDN sources](/discover/migration/object-and-cdn-sources) / [Backblaze B2 S3 bucket](/discover/migration/backblaze-b2-s3-bucket) / [Migrate Backblaze B2 S3 bucket: Public media library](/migrate/backblaze-b2-s3-bucket/public-media-library)