---
title: "Host mcp server with Express: Postgres-backed state"
description: "Deploy a mcp server built with Express on Ample using the durable job state pattern."
canonical_url: "https://ample.computer/recipes/mcp-server/express/persistent-state"
last_updated: "2026-09-21"
---

# Host mcp server with Express: Postgres-backed state

Canonical URL: https://ample.computer/recipes/mcp-server/express/persistent-state
Formats: [HTML](https://ample.computer/recipes/mcp-server/express/persistent-state) | [Markdown](https://ample.computer/recipes/mcp-server/express/persistent-state.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Amcp-server%3Aexpress%3Apersistent-state)
Recipe ID: `page:recipes:mcp-server:express:persistent-state` | Revision: `r1` | Catalog revision: `cat_f13ab9a494120b5e`

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

## Summary

Deploy a mcp server built with Express on Ample using the durable job state pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Express: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Not separately tested: your job types, payload schema and retry policy; treat the mcp server-specific behavior as your application code.

Path: [Agent hosting discovery](/discover/discovery) / [Applications and workloads](/discover/workload) / [Agents and backends](/discover/workload/agents-and-backends) / [MCP server](/discover/workload/mcp-server) / [Host mcp server with Express: Postgres-backed state](/recipes/mcp-server/express/persistent-state)

## Infrastructure requirements

- [Compute](/discover/primitive/compute): verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- [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

- An Express project that builds and starts with the documented commands (npm install, npm run build --if-present, npm run start on the node-22 template)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- 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. **Build and start.** npm install, npm run build --if-present, npm run start on the node-22 template. The server must bind 0.0.0.0 on PORT.
2. **Implement the pattern on PostgreSQL.** The fixture's module implements durable job state: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. **Deploy.** Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.

   ```
   ample deploy . --name <app-name> --public
   ```
4. **Verify.** Fetch the live URL and the pattern self-test route(s) (/p/durable-job-state) from the example; then run your own checks. On failure read `ample logs <deployment_id> --kind build` then `--kind runtime`.

   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Express pattern fixture** (tests/deploy-canaries/express-patterns): Multi-pattern Express app whose durable job state module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary express patterns)
- durable-job-state self-test (`/p/durable-job-state` on the live URL, expect job=done attempts=1 idempotent=true)


## 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

Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Verification evidence

- canary_run on 2026-09-21T02:34:39Z at revision `1d28ae0 (CLI 0.1.21)`: Express pattern fixture deployed on Ample (npm install, npm run build --if-present, npm run start on the node-22 template); checks passed for durable-job-state and configuration-secrets. Pattern proof: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). (expires 2027-03-20T02:34:39Z)
- canary_run on 2026-09-20T01:54:51Z at revision `199ff1dfd52683832ae75d3f98b53a7a4bff7f96 (CLI e3181f5)`: The same Express app deployed with a --release-command migration; the marker it created was readable after activation. (expires 2027-03-19T01:54:51Z)

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


## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-22T00:31:22.774679+00:00 at revision `e6446ceea69b`, binding state `current`, required scopes: servers:write, databases:read.

## Input schema

```json
{
  "additionalProperties": false,
  "properties": {
    "env": {
      "description": "Encrypted environment variables (bucket credentials, secrets)",
      "items": {
        "pattern": "^[A-Z][A-Z0-9_]*=.*$",
        "type": "string"
      },
      "maxItems": 50,
      "type": "array"
    },
    "name": {
      "description": "App name",
      "maxLength": 63,
      "minLength": 1,
      "pattern": "^[a-z0-9-]+$",
      "type": "string"
    },
    "path": {
      "description": "Project directory or ample.toml service",
      "maxLength": 512,
      "minLength": 1,
      "type": "string"
    },
    "release_command": {
      "description": "Migration command run before activation",
      "maxLength": 512,
      "type": "string"
    }
  },
  "required": [
    "name",
    "path"
  ],
  "type": "object"
}
```

## 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 MCP server (GET /v1/catalog/nodes/workload%3Amcp-server on the api origin; auth: false, approval: false)
- Browse Express (GET /v1/catalog/nodes/stack%3Aframework-express on the api origin; auth: false, approval: false)
- Browse Durable job state (GET /v1/catalog/nodes/pattern%3Adurable-job-state on the api origin; auth: false, approval: false)
- Browse Deploy MCP server (GET /v1/catalog/nodes/intent%3Adeploy-mcp-server on the api origin; auth: false, approval: false)

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