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Documentation Index

Fetch the complete documentation index at: https://docs.fact0.io/llms.txt

Use this file to discover all available pages before exploring further.

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Mastra

Mastra is TypeScript-native, so it pairs directly with @fact0/sdk.

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Install

npm install @fact0/sdk @mastra/core

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Pattern

Wrap agent generation in a telemetry execution and audit high-value tool calls. 
import { Fact0Client } from "@fact0/sdk";
import { Agent } from "@mastra/core/agent";
import { openai } from "@ai-sdk/openai";

const lf = new Fact0Client({ apiKey: process.env.FACT0_API_KEY! });

const agent = new Agent({
  name: "support",
  instructions: "Resolve customer tickets.",
  model: openai("gpt-4o"),
  tools: { lookupOrder, issueRefund },
});

const execution = await lf.telemetry.startExecution({ agentId: "mastra.support" });

const span = execution.startSpan("agent.generate", "MODEL_INVOCATION");
const response = await agent.generate("Refund order #1024");
span.complete({ text: response.text });

await execution.end();

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Audit a tool call

async function issueRefund({ orderId }: { orderId: string }) {
  await lf.audit.log({
    actor: { id: "agent.support", type: "agent" },
    action: "order.refund",
    resource: { id: orderId, type: "order" },
    outcome: "success",
  });
  ...
}
Mastra runs server-side. Never expose alk_live_* keys to the browser.