page:recipes:mcp server:fastapi:artifact storage

Host mcp server with FastAPI: stored input and output artifacts

Summary

Deploy a mcp server built with FastAPI on Ample using the generated downloads 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, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on FastAPI: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the mcp server-specific behavior as your application code.

Representative Queries

Resource Requirements

Infrastructure Requirements

  1. Compute: 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: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
  3. S3-compatible object storage: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

Framework

FastAPI

Workload

MCP server

Release Status

Published

Support Status

Verified

Execution Status

Ready

Prerequisites

Tested Configuration

Workflow Steps

  1. Build and start: pip install into .ample/python from requirements.txt, then uvicorn from run.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: The fixture's module implements generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
  3. Wire object storage: Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket.
  4. 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.
    • Command: ample deploy . --name --public --start "python3 run.py" --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...
  5. Verify: Fetch the live URL and the pattern self-test route(s) (/p/generated-downloads) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.
    • Command: ample logs --kind build

Examples

Success Checks

  1. App responds on its public URL: Kind - http_get, Path - /, Expect - ample canary fastapi patterns
  2. Generated-downloads self-test: Kind - http_get, Path - /p/generated-downloads, Expect - export=ok rows=3 (with ?token=...; 401 without)

Limitations

Cost Estimate

Evidence Summary

  1. Canary run: FastAPI pattern fixture deployed on Ample; checks passed for generated-downloads 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
  2. Canary run: The same FastAPI app deployed with a --release-command migration.
    • Observed At: 2026-09-20T01:54:51Z
    • Implementation Revision: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)
    • Expires At: 2027-03-19T01:54:51Z

Unknowns

Formats

Next Actions