SDK Quickstart - Docs

Deploy with the Buildfunctions SDK

Get Started

1. First Install

   npm

   npm install buildfunctions
   

   Mojo coming soon! 🔥
2. Create an API token

   Create an API token at https://www.buildfunctions.com/settings

   
3. Authenticate

   Write your agent app code and authenticate with the Buildfunctions SDK:

   JavaScript

   ...
   const apiToken = process.env.BUILDFUNCTIONS_API_TOKEN
   if (!apiToken) {
     return new NextResponse('Missing BUILDFUNCTIONS_API_TOKEN', { status: 500 })
   }
   
   // Authenticate with a Buildfunctions API token
   await Buildfunctions({ apiToken })
   ...
   
4. Create a GPU Sandbox and run inference

   JavaScript

   ...
   // Create a GPU Sandbox with Python and PyTorch
   const sandbox = await GPUSandbox.create({
     name: 'secure-agent-action',
     memory: '50000MB',
     gpu: 'T4G',
     timeout: 1200, // 24 hours max
     language: 'python', // language available within sandbox
     code: inferenceCode, // inline code or path to file
     requirements: ['transformers', 'torch', 'accelerate'], // python dependencies
     model: '/path/to/models/Qwen/Qwen3-8B', // path to folder with models can be local or remote (e.g., Hugging Face)
   })
   
   // Run inference within hardware-isolated VM (full GPU access)
   const result = await sandbox.run()
   ...
   
   
5. Add Runtime Controls

   Help keep your agent running unattended. Runtime Controls wrap function calls with composable guardrails — no API key required.

   JavaScript

   import { RuntimeControls } from 'buildfunctions'
   
   const controls = RuntimeControls.create({
     maxToolCalls: 50,
     timeoutMs: 30_000,
     retry: { maxAttempts: 3, initialDelayMs: 200, backoffFactor: 2 },
     loopBreaker: { warningThreshold: 5, quarantineThreshold: 8, stopThreshold: 12 },
     onEvent: (event) => console.log(`[controls] ${event.type}: ${event.message}`),
   })
   
   const guardedFetch = controls.wrap({
     toolName: 'api-call',
     runKey: 'agent-run-1',
     destination: 'https://api.example.com',
     run: async ([payload]) => {
       const res = await fetch('https://api.example.com/data', {
         method: 'POST',
         body: JSON.stringify(payload),
       })
       return res.json()
     },
   })
   
   const result = await guardedFetch({ query: 'latest results' })
   
   // Reset budget counters when starting a new run
   await controls.reset('agent-run-1')
   

   Works standalone or combined with Buildfunctions hardware-isolated sandboxes. For backend-specific integrations, validate behavior with your own integration tests. See the full Runtime Controls docs for all control layers.

Buildfunctions is currently in its beta stage. If you encounter any issues or have specific syntax requirements, please reach out and contact us, and we’ll work to address them.