Symbiont — Developer Guide

01

Install

Three ways to get Symbiont on your machine. The install script auto-detects your platform and drops the binary into /usr/local/bin.

terminal

recommended

# Install script — auto-detects OS & arch
$ curl -fsSL https://symbiont.dev/install.sh | bash

  Detected: linux-x86_64
  Downloading symbiont v1.15.2...
  ✓ Installed to /usr/local/bin/symbi

terminal

# From crates.io
$ cargo install symbi

terminal

# Docker image
$ docker pull ghcr.io/thirdkeyai/symbi:latest

02

Initialize

Interactive project setup. Generates Cedar policies, agent definitions, and sandbox configuration in one pass.

terminal

$ symbi init my-project
? Select a profile: minimal
? Enable SchemaPin verification? yes
? Sandbox tier: docker

  ✓ Created my-project/symbiont.toml
  ✓ Created my-project/policies/default.cedar
  ✓ Created my-project/agents/assistant.symbi
  ✓ Created my-project/.env.example

  cd my-project && symbi run assistant

03

Write Agents

Declarative DSL for agent definitions. Supports both // and # comment styles. Model, tools, policies, and behavior in a single file.

assistant.symbi

// Agent definition — declarative DSL
# Both comment styles are supported

agent assistant {
    model       "gpt-4o"
    temperature 0.3
    max_turns   10

    system "You are a helpful assistant."

    tools [web_search, file_read]

    policy "policies/default.cedar"
    sandbox docker
}

04

Run

Test agents locally with a single command. Full reasoning loop, policy enforcement, and token tracking out of the box.

terminal

$ symbi run assistant -i 'hello'

  ▸ Loading agent: assistant
  ▸ Policy check: ✓ default.cedar
  ▸ Sandbox: docker

  Hello! I'm your assistant. How can I help you today?

  ──────────────────────────────────
  iterations: 1 │ tokens: 142 │ tools: 0

05

Deploy

Start the full runtime with API server, auto-routing, and all configured agents. Production-ready from a single command.

terminal

$ symbi up

  ╭──────────────────────────────────────╮
  │  Symbiont Runtime                    │
  ╰──────────────────────────────────────╯

  ✓ Auth: bearer token (JWT + Cedar)
  ✓ Loaded 3 agents: assistant, researcher, coder
  ✓ Auto-routing: enabled
  ✓ SchemaPin: verified
  ✓ Sandbox tier: docker

  Listening on http://0.0.0.0:3000
  Docs at      http://0.0.0.0:3000/docs

06

Feature Flags

Toggle capabilities at compile time or in symbiont.toml.

Flag	Description	Default
cedar	Cedar policy engine	on
schemapin	SchemaPin tool verification	on
toolclad	ToolClad declarative tool contracts	on
sandbox	Docker/gVisor/Firecracker sandboxing	on
audit	Cryptographic audit trail	on
cron	Cron-based agent scheduling	on
metrics	OTLP telemetry export	off

07

SDKs

First-class client libraries for JavaScript and Python. Full typed API, streaming support, and built-in auth.

GitHub: symbiont-sdk-js GitHub: symbiont-sdk-python

javascript

$ npm i symbiont-sdk-js

import { Symbiont } from 'symbiont-sdk-js'

const client = new Symbiont({
  baseUrl: 'http://localhost:3000',
  token:   process.env.SYMBIONT_TOKEN
})

python

$ pip install symbiont-sdk

from symbiont import Symbiont

client = Symbiont(
    base_url="http://localhost:3000",
    token=os.environ["SYMBIONT_TOKEN"]
)

08

Govern Your Coding Assistant

First-party plugins bring Symbiont governance directly into your coding workflow. Three tiers of protection — from advisory logging to hard Cedar policy enforcement.