For the complete documentation index optimized for AI agents, see llms.txt or llms-full.txt. A markdown version of this page is available by appending.mdto the URL or sendingAccept: text/markdown.
a4-server
For AI agents: the documentation index is at llms.txt (full corpus: llms-full.txt). A markdown source for this page is /a4-server/overview.md.
a4-server is a Rust crate that lets you run your compiled stack as a standalone WebSocket server. It connects to a Yellowstone gRPC endpoint, processes Solana data through your projections, and streams the results to connected clients.
Prerequisites
Section titled “Prerequisites”To run a stack with a4-server, you need:
| Requirement | Description |
|---|---|
| Yellowstone gRPC Endpoint | A URL to a Solana node running the Yellowstone Geyser plugin. This is your source of blockchain data. |
| X-Token | Authentication token for your Yellowstone provider (most providers require this). |
| Rust 1.75+ | Required to build the server binary. |
| A compiled stack | Your stack crate with the #[arete(...)] macro, which generates a spec() function. |
Environment Variables
Section titled “Environment Variables”a4-server reads configuration from environment variables:
| Variable | Required | Description |
|---|---|---|
YELLOWSTONE_ENDPOINT | Yes | Your Yellowstone gRPC endpoint URL |
YELLOWSTONE_X_TOKEN | Usually | Authentication token for the endpoint |
When to Use a4-server
Section titled “When to Use a4-server”Use a4-server when:
- Developing and testing stacks locally
- Running a single stack in your own infrastructure
- You need full control over the server deployment
- You already have Yellowstone gRPC access
Consider Arete Cloud when:
- You need multi-stack orchestration
- You want managed Yellowstone infrastructure
- You need built-in authentication and API keys
- You prefer zero-config deployment