Duso - Frictionless Server Development

Build as a Single Binary

App code, full runtime, all dependencies in a single 10MB executable.

Deploy Anywhere

Supports Linux, macOS, and Windows. One build, every platform.

Make Web and API Servers

Templates, routing, JSON, SSL, JWT, CORS, RSA, websockets. Fully featured and built-in.

Use Powerful Datastores

Thread-safe data structures for process coordination, caching, and session state.

Handle Massive Concurrency

Simple API backed by Go's efficient goroutines. Run thousands of parallel operations.

Debug Concurrent Code

Breakpoints, stack traces, code context. Handle one issue at a time.

Use and Integrate AI

Let your AI code faster in a language made for it. Connect your app to popular AI agents.

Secure Local Files

Sandbox mode restricts file access and uses virtual filesystem for safety.

Complete Runtime Library

Full standard library and community contributions. Everything included in each binary release.

Built-in Documentation

120+ functions and library modules with integrated examples and guides. Learn as you build.

Powered by Go

Duso is written in in Go, made by Google for solid and efficient concurrency at scale.

Open Source

Apache 2.0 licensed. Community-driven and fully transparent.

Hook up your AI

Duso was designed to be quickly learned by most AI coding assistants.

# start here!
duso -read

# look up a specific function or lib
duso -doc claude

Basic AI Prompt

One-shot Q&A style prompts are easy.

ai = require("ollama")
print(ai.prompt("sup?"))

Basic Chatbot

You can add system prompt and tools, but this will get you started. Displays a cute "busy" spinner while waiting for a response.

ai = require("openai")
chat = ai.session()

while true do
  prompt = input("\n\nYou: ")

  if lower(prompt) == "exit" then break end

  write("\n\nOpenAI: ")
  busy("thinking...")
  write(chat.prompt(prompt))
end

AI Workflow

Prompts experts in parallel, gathers their responses, then runs them through a summary prompt.

ai = require("claude")

prompt = input("Ask the panel: ")
busy("asking...")

// build an array of functions to prompt
// each expert, then run them all in parallel
experts = ["Astronomer", "Astrologer", "Biologist", "Accountant"]
responses = parallel(map(experts, function(expert)
  return function()
    return ai.prompt(prompt, {
      system = """
        You are an expert {{expert}}. Always reason and
        interact from this mindset. Limit your field of
        knowledge to this expertise.
      """,
      max_tokens = 500
    })
  end
end))

// prepend the expert type into their response
for i = 0, 3 do
  responses[i] = "{{experts[i]}} says: {{responses[i]}}"
end

busy("summarizing...")
summary = ai.prompt("""
  Summarize these responses:

  {{join(responses, "\n\n---\n\n")}}

  List 3 the things they have in common.
  Then list the 3 things that are the most different.
  Don't separate with ---
""")

// format the markdown response for the terminal
print(markdown_ansi(summary))

One Line Web Server

You can run a web server from the command line.

# http://localhost:8080
duso -c 'http_server().start()'

API Server

Build an HTTP API with routing and JSON responses. Best practice is one handler script per route to make each more manageable and efficient at runtime. Each time a route is triggered, http_server runs a new instance of that script to handle it. It has a simple API but with hyper-efficient goroutines underneath.

// server.du
port = 3000
server = http_server({port = port})

server.route("GET", "/api/user/:id", "user-get.du")
server.route("POST", "/api/user", "user-post.du")

print("Server running at http://localhost:{{port}}")
server.start()

// ...script blocks while server is running...

print("Server stopped.")

// user-get.du
ctx = context()
req = ctx.request()
res = ctx.response()

user = datastore("users").get(req.params.id)

if not user then res.error(404) end

res.json({
  success = true,
  data = user
}, 200)

// user-post.du
ctx = context()
req = ctx.request()
res = ctx.response()

id = uuid()

datastore("users").set(id, req.body)

res.json({
  id = id,
  name = req.body.name
}, 201)