SteerPlane — TypeScript SDK

Runtime control plane for autonomous AI agents.

npm install steerplane

Quick Start

Higher-Order Function (Simplest)

import { guard } from 'steerplane';

const runAgent = guard(
  async () => {
    // Your agent code here
    await agent.run();
  },
  {
    agentName: 'support_bot',
    maxCostUsd: 10.00,
    maxSteps: 50,
  }
);

await runAgent();

Class API (Full Control)

import { SteerPlane } from 'steerplane';

const sp = new SteerPlane({ agentId: 'my_bot' });

await sp.run(async (run) => {
  await run.logStep({ action: 'query_db', tokens: 380, cost: 0.002 });
  await run.logStep({ action: 'call_llm', tokens: 1240, cost: 0.008 });
  await run.logStep({ action: 'send_email', tokens: 120, cost: 0.001 });
}, { maxCostUsd: 10 });

Manual Lifecycle

import { SteerPlane } from 'steerplane';

const sp = new SteerPlane({ agentId: 'my_bot' });
const run = sp.createRun({ maxCostUsd: 10 });

await run.start();
await run.logStep({ action: 'search', tokens: 100, cost: 0.001 });
await run.logStep({ action: 'generate', tokens: 1240, cost: 0.008 });
await run.end();

Features

| Feature | Description | |---------|-------------| | 🛡️ Policy Engine (New in v0.3.0) | Strict allow/deny lists, sliding-window rate limits, and approval workflows. | | 🌉 AI Gateway Proxy (New in v0.3.0) | Zero-code integration. Set your OpenAI base url to the SteerPlane Gateway. | | 🔄 Loop Detection | Sliding-window pattern detector catches repeating agent behavior | | 💰 Cost Limits | Hard USD ceiling per run — terminate instantly when exceeded across 25+ models | | 🚫 Step Limits | Cap maximum execution steps | | 📊 Deep Telemetry | Every step logged to the SteerPlane dashboard with token counts and latency | | 🛡️ Graceful Degradation | If API is down, guards still work locally | | ⚡ Zero Dependencies | Uses native fetch — no bloat |

Error Handling

import { guard, CostLimitExceeded, LoopDetectedError } from 'steerplane';

const runAgent = guard(async () => {
  try {
    await agent.run();
  } catch (err) {
    if (err instanceof CostLimitExceeded) {
      console.log(`Budget exceeded: ${err.currentCost}`);
    }
    if (err instanceof LoopDetectedError) {
      console.log(`Loop pattern: ${err.pattern}`);
    }
  }
}, { maxCostUsd: 5 });

Environment Variables

| Variable | Default | Description | |----------|---------|-------------| | STEERPLANE_API_URL | http://localhost:8000 | SteerPlane API server URL |

Requirements

• Node.js 18+
• SteerPlane API server running (for dashboard integration)

License

MIT