### Host vendor portal with Flask: application activity history

Deploy a vendor portal built with Flask on Ample using the transactional workflows 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 Flask: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Not separately tested: your domain records, validation rules and concurrency policy; treat the vendor portal-specific behavior as your application code.

#### Representative Queries
- Host vendor portal with Flask: application activity history
- Where can I host Vendor portal built with Flask?
- I need an application-owned event schema and tested history queries; not native platform audit logs.

#### Resource Requirements
- **Compute**
- **Postgres**

#### Infrastructure Requirements
1. **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.
2. **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
- A Flask project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 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

#### Tested Configuration
- **Template:** python-3.12
- **Runtime:** python
- **Size:** s-1vcpu-1gb
- **Install:** python3 -m pip install --target .ample/python -r requirements.txt
- **Start:** PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 app.py

#### Workflow Steps
1. **Build and start**  
   body: `pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template. The server must bind 0.0.0.0 on PORT.`
2. **Implement the pattern on PostgreSQL**  
   body: `The fixture's module implements transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.`
3. **Deploy**  
   body: `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.`  
   command: `ample deploy . --name  --public --start \"python3 app.py\"`
4. **Verify**  
   body: `Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read \\`ample logs  --kind build\\` then \\`--kind runtime\\`.`  
   command: `ample logs  --kind build`

#### Examples
- **Flask pattern fixture**  
  Description: Multi-pattern Flask app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.  
  Source Ref: tests/deploy-canaries/flask-patterns

#### Success Checks
- **App responds on its public URL**  
   kind: `http_get`, path: `/`, expect: `ample canary flask patterns`
- **Transactional-workflows self-test**  
   kind: `http_get`, path: `/p/transactional-workflows`, expect: `tx=ok history=2 conflict=rejected`

#### Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Flask major versions are not verified.
- The vendor portal itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

#### Cost Estimate
- Currency: USD
- Monthly Amount: 10.0
- Authoritative: true
- Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- Components:  
  - **App server**: size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0  
  - **Managed PostgreSQL database**: size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0
- Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

#### Evidence Summary
1. **Canary run**:  
   Summary: Flask pattern fixture deployed on Ample (pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 template); checks passed for transactional-workflows and configuration-secrets.
   - Observed At: 2026-09-21T01:14:18Z
   - Implementation Revision: 50dbac567d2c5cc8e55e6c748a646be0025d9cfb-dirty (CLI 0.1.21)
   - Expires At: 2027-03-20T01:14:18Z
   - Scope:  
     - Checks: [/p/transactional-workflows]
     - Pattern: pattern:transactional-workflows
     - Template: python-3.12
2. **Canary run**:  
   Summary: The same Flask app deployed with a --release-command migration; the marker it created was readable after activation.
   - Observed At: 2026-09-20T01:54:51Z
   - Implementation Revision: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)
   - Expires At: 2027-03-19T01:54:51Z
   - Scope:  
     - Pattern: pattern:transactional-workflows

#### Last Verified At
2026-09-21T01:14:18Z

#### Unknowns
- Region availability is unknown until a verified region fact is recorded
- Compliance attestations are unknown; none are claimed

#### Formats
- HTML: [https://ample.computer/recipes/vendor-portal/flask/activity-history](/content/recipes/vendor-portal/flask/activity-history/index.html)  
- Markdown: [https://ample.computer/recipes/vendor-portal/flask/activity-history.md](/content/recipes/vendor-portal/flask/activity-history.md)  
- JSON: [https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Avendor-portal%3Aflask%3Aactivity-history](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Avendor-portal%3Aflask%3Aactivity-history)