NullRun Docs

Source for the docs.nullrun.io site.

What's inside

• Getting started — install, quickstart, SDK configuration.
• Concepts — how budgets, circuit breaker, control plane, sensitive tools, and workflow context work.
• How-to — recipes for specific frameworks and scenarios (LangGraph, OpenAI Agents, cost cap).
• Reference — full SDK / HTTP API / error codes reference.

Where to start

If you want to...	Open
Try it in 5 minutes	Quickstart
Wire up the SDK for production	Configuration
Track or cap spend	Budgets + Cost cap how-to
Use LangGraph	How-to → LangGraph
Use OpenAI Agents	How-to → OpenAI Agents
Debug 4xx / 5xx responses	Error codes
See the full SDK surface	SDK API reference

Full page list

Getting started

• Install · pip install nullrun, API key, auto-instrumentation
• Quickstart · @protect in 30 lines
• Configuration · env vars, fallback modes, gRPC status

Concepts

• Circuit breaker · CLOSED / OPEN / HALF_OPEN
• Budgets · pre-flight /check + reservation /execute
• Sensitive tools · fail-CLOSED, always
• Workflow context · nullrun.workflow(...) and what it does
• Control plane (WebSocket) · real-time kill / pause

How-to

• Protect a LangGraph agent
• Use with OpenAI Agents
• Set a hard cost cap

Reference

• SDK API · init, @protect, @sensitive, workflow, exceptions
• HTTP API · /track, /gate, /check, /execute, WebSocket
• Error codes · validation_error, RateLimitError, kill contract

What you need from us

• API key — create one in nullrun.io → Settings → API keys. You get a nr_live_… public identifier and an HMAC secret, shown once.
• Python ≥ 3.10 for the SDK.
• Nothing else to read the docs — the site is public.

Other NullRun repositories

• nullrun-sdk-python — Python SDK (pip install nullrun)
• nullrun-examples — runnable examples
• .github — organisation profile, SECURITY / SUPPORT
• nullrun — gateway + dashboard (private repository, access on request)