## The short version

A public directory blueprint for construction contractors built with Next.js on Ample. Domain schema: listings (reference, project_type, location, publishing_status, agency_id): showcase projects with publishing status; agencies (name, license_number, service_region): branches or divisions; vendors (name, trade, agency_id, prequalified): subcontractors and suppliers per branch; reports (agency_id, period, object_key, generated_at): branch progress reports; state_transitions (record_type, from_state, to_state): the allowed state machine. Public information: published project showcases, services and regions, licenses and insurance summary. Kept out of scope until handling is reviewed: site safety incidents, bid pricing, client contracts. Safety and bid data are confidential; only published showcases and branch reporting are modeled. Technical basis verified on Next.js: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true).

## What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)
- [Postgres](/content/discover/primitive/postgres/index.html): 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.)
- [CDN](/content/discover/primitive/cdn/index.html): verified (A published bucket's objects are served at its public_url. It does not front app compute and is not a cache or key-value store.)

## Before you start

- A Next.js project (next build then next start -H 0.0.0.0 -p $PORT on the node-22 template)
- A PostgreSQL driver reading DATABASE_URL (auto-provisioned when omitted)
- Bucket credentials from `ample bucket create` passed as encrypted S3_* environment variables and a published bucket for public assets (CDN_*)
- A review of which construction contractors data classes may be handled at all; this blueprint models public information only

## How to do it

1. **Model the construction contractors domain**  
   Create the tables listings, agencies, vendors, reports, state_transitions. Showcase projects with publishing status lives in listings; keep the sensitive classes (site safety incidents, bid pricing, client contracts) out of this schema.

2. **Workflow step 1**  
   Model listings with a publishing_status state machine scoped to the agency

3. **Workflow step 2**  
   Serve only published listings, with media from the CDN bucket

4. **Workflow step 3**  
   Enforce the agency scope on every query

5. **Workflow step 4**  
   Deploy and verify a published listing and that unpublished listings are absent

6. **Deploy**  
   Run the synchronous deploy once and read the result. Re-running with no change is a no-op.

```
   ample deploy . --name <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... --env CDN_PUBLIC_URL=...
   ```

7. **Verify**  
   Run the pattern self-test(s) from the example (/p/relational-records) and your own acceptance checks for the construction contractors workflow.

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

## Tested examples

- **Next.js pattern fixture** (`tests/deploy-canaries/next-js-patterns`): Verified relational records basis for this blueprint.

## How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary next js patterns)
- relational-records self-test from the example (`/p/relational-records` on the live URL, expect see the pattern fixture checks)

## Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. 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)`: Next.js pattern fixture deployed on Ample (next build then next start -H 0.0.0.0 -p $PORT on the node-22 template); the relational records checks passed: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). The blueprint's Construction contractors schema and workflow below build on that verified basis and were not separately executed. (expires 2027-03-20T02:34:39Z)

## Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Construction contractors (`GET /v1/catalog/nodes/industry%3Aconstruction-contractors` on the api origin; authentication not required, approval not required)
- Browse Public directory (`GET /v1/catalog/nodes/workload%3Apublic-directory` on the api origin; authentication not required, approval not required)
- Browse Next.js (`GET /v1/catalog/nodes/stack%3Aframework-next-js` on the api origin; authentication not required, approval not required)
- Browse Deploy web app (`GET /v1/catalog/nodes/intent%3Adeploy-web-app` on the api origin; authentication not required, approval not required)

Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.

## Identifiers and status

Recipe `page:blueprints:construction-contractors:public-directory:next-js`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**

Formats: [HTML](/content/blueprints/construction-contractors/public-directory/next-js/index.html) \| [Markdown](/content/blueprints/construction-contractors/public-directory/next-js.md) \| [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Ablueprints%3Aconstruction-contractors%3Apublic-directory%3Anext-js)