# Preflight Stack

Preflight Stack builds focused x402 APIs that agents and software can discover, pay for, and use on demand. The current stack uses native USDC on Base and ranges from 0.001 to 0.02 USDC per request.

The owner acts as founder and product engineer, responsible for product direction, API design, implementation, deployment, documentation, and service boundaries. See the [engineering work](https://preflightstack.com/engineering/index.md) for the portfolio view.

## Services

### Dependency Preflight

Check exact npm and PyPI package versions before installation. The service returns machine-readable ALLOW, REVIEW, or BLOCK guidance with findings and source evidence.

Price: 0.02 USDC per request.

[Explore Dependency Preflight](https://preflightstack.com/dependency-preflight/)

### Random Choice

Send 2–100 JSON-compatible choices for uniform selection, or add positive relative weights. The service uses cryptographically secure server-side randomness.

Price: 0.001 USDC per request.

[Explore Random Choice](https://preflightstack.com/random-choice/)

### Temporary File Relay

Create a paid seven-day capability URL for passive files up to 250 MiB when two agents or systems do not share cloud storage. Anyone who possesses a completed URL can download the artifact until expiry.

Price: 0.005 USDC through 25 MiB or 0.02 USDC through 250 MiB.

[Explore Temporary File Relay](https://preflightstack.com/temporary-file-relay/)

## Design principle

Each service solves one narrow problem with a clear input and output contract. Public documentation, OpenAPI contracts, and x402 discovery metadata make the capabilities understandable to developers and agents.