---
title: "Migrate Heroku Postgres: JSON document metadata"
description: "Move PostgreSQL data from Heroku Postgres to Ample, one component at a time."
canonical_url: "https://ample.computer/migrate/heroku-postgres/json-document-metadata"
last_updated: "2026-09-21"
---

# Migrate Heroku Postgres: JSON document metadata

Canonical URL: https://ample.computer/migrate/heroku-postgres/json-document-metadata
Formats: [HTML](https://ample.computer/migrate/heroku-postgres/json-document-metadata) | [Markdown](https://ample.computer/migrate/heroku-postgres/json-document-metadata.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Amigrate%3Aheroku-postgres%3Ajson-document-metadata)
Recipe ID: `page:migrate:heroku-postgres:json-document-metadata` | Revision: `r1` | Catalog revision: `cat_f13ab9a494120b5e`

Status: release `published`, support `verified`, execution `unbound`

## Summary

Move PostgreSQL data from Heroku Postgres to Ample, one component at a time. Destination verified on Ample: a jsonb column with a GIN index queried by path and containment, with an aggregate over matching documents (json=ok). Source procedure: Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`. Not migrated automatically: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database. Cutover: Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database until confirmed. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Path: [Agent hosting discovery](/discover/discovery) / [Migration sources by component](/discover/migration) / [Postgres sources](/discover/migration/postgres-sources) / [Heroku Postgres](/discover/migration/heroku-postgres) / [Migrate Heroku Postgres: JSON document metadata](/migrate/heroku-postgres/json-document-metadata)

## Infrastructure requirements

- [Postgres](/discover/primitive/postgres): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.)

## Prerequisites

- Authorized access to the Heroku Postgres 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, databases:read

## 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 Heroku Postgres provides beyond the component you are moving. Out of scope here: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database.
2. **Source step 1.** Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`
3. **Source step 2.** Check the Postgres major version and extensions against the managed engine (PostgreSQL 16)
4. **Source step 3.** Restore into a scratch managed database first and compare row counts
5. **Provision and restore.** Deploy the app once so a managed PostgreSQL 16 database exists (or create one with `ample database create --engine postgres`), then restore the dump with pg_restore using its connection string; keep migrations idempotent.

   ```
   ample database create --name <db-name> --engine postgres
   ```
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/json-document-metadata).
7. **Cut over.** Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database 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: JSON document metadata.

## Success checks

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


## Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision 515b7316fc6e5a81679407ae0c811146ceb2c5c7).
- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample.

## Verification evidence

- canary_run on 2026-09-21T02:34:39Z at revision `1d28ae0 (CLI 0.1.21)`: 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 (a jsonb column with a GIN index queried by path and containment, with an aggregate over matching documents (json=ok)). The source-side export from Heroku Postgres is documented from the vendor's standard tooling and was not executed by this catalog's evidence. (expires 2027-03-20T02:34:39Z)

Last verified: 2026-09-21T02:34:39Z


## Execution binding

No execution binding. This recipe is documentation only; nothing is executed automatically.

## 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 Heroku Postgres (GET /v1/catalog/nodes/migration%3Aheroku-postgres on the api origin; auth: false, approval: false)
- Browse JSON document metadata (GET /v1/catalog/nodes/pattern%3Ajson-document-metadata on the api origin; auth: false, approval: false)
- Browse Migrate Postgres (GET /v1/catalog/nodes/intent%3Amigrate-postgres on the api origin; auth: false, approval: false)

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