> ## Documentation Index
> Fetch the complete documentation index at: https://headgate.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Introduction
> A policy-aware distributed job queue for Rust and Go, backed by PostgreSQL, MySQL, or Redis.
# The admission gate for background work
Most job queues ask the store for the next jobs. Headgate asks a different question:
**given fleet policy and available capacity, what may this worker run?** The store answers
atomically while it claims and leases the work.
Define a typed task, enqueue it, and drain a worker using the in-memory store.
See how rate limits, fairness, concurrency, and quarantine become one admission decision.
Compose durable fan-out and fan-in dependencies in Rust or Go.
Understand the control API, then use the interactive endpoint reference.
## Why headgate
Rate limits and concurrency ceilings are shared across every worker process.
Rust and Go implement the same contracts from shared specifications and conformance tests.
PostgreSQL, MySQL, and Redis expose matching core behavior and honest optional capabilities.
## The execution path
```mermaid theme={"system"}
flowchart LR
A[Producer client] -->|validated envelope| B[(Store)]
C[Worker capacity] --> D{Atomic admission gate}
B --> D
D -->|claim + lease| E[Typed handler]
E -->|fenced outcome| B
```
The worker never reimplements fleet policy. Moving policy evaluation out of the store would
make the result dependent on which worker happened to poll.
## Pick your path
```bash Rust theme={"system"}
cargo run --manifest-path examples/rust/Cargo.toml --bin basic
```
```bash Go theme={"system"}
cd examples/go
GOWORK=off go run ./basic
```
Build and verify your first job without installing a database.