Sausage

You can see how the sausage is made.

Sausage is a world of small programs ("actors") that you grow by talking to it. Each actor is a WASI program with stdin and stdout. Actors send each other JSON messages, one per line, through a broker. The agent is an actor too: it writes new actors in Rust, builds them, tests them, starts them, and can change its own code.

Start

You need Nix with flakes.

nix run -- init     # creates ./world and builds the agent (a few minutes)
nix run -- run      # starts the world and a console

init asks for the API shape (openai-responses or anthropic-messages), the base URL, the model, and the token. It reads SAUSAGE_API, SAUSAGE_BASE_URL, SAUSAGE_MODEL, and SAUSAGE_API_TOKEN first. The values go to world/actor/agent/data/config.json. Both commands take another folder as an argument, for example nix run -- run my-world.

In the console:

write an actor "notes" that stores notes, and start it   → text to the agent
@notes {"type":"add","text":"milk"}                      → a JSON message to an actor
@agent hello                                             → text to an actor
/quit

The world folder

The folder is the source of truth. Every actor lives in world/actor/<id>/:

actor.wasm     the current version
actor.json     installed version, running, subscriptions
source/        the source of the current version
public/        files that the actor publishes
data/          the actor's state
stderr.log     what the actor and the broker write about it
versions/<n>/  every installed version: actor.wasm, source/, meta.json

To add or replace an actor by hand, put an actor.wasm (and its source/, with the tests in source/tests/) into its folder. Then restart the world or send @broker {"type":"scan"}. The broker tests the file before it uses it. If the tests fail, the old version keeps running, and stderr.log says why.

More

• PROTOCOL.md: messages, the filesystem, the broker, cargo. Read this to write an actor in any language.
• sdk/: sausage-actor, the SDK for Rust actors.
• examples/notes: a small actor with a test.
• AGENTS.md: how to work on Sausage itself.