Mastra

The Gateway is an OpenAI-compatible API proxy with built-in Observational Memory. Point any HTTP client, SDK, or framework at the gateway and every conversation is automatically remembered without any memory management code.

Learn more in the Gateway documentation.

Get an API key

Go to gateway.mastra.ai and sign up for a Mastra account. During the onboarding you'll get your personal API key to authenticate requests.

Usage

Define your API key as an environment variable:

.env

MASTRA_GATEWAY_API_KEY=your-gateway-key

Set your gateway model ID:

src/mastra/agents/my-agent.ts

import { Agent } from "@mastra/core/agent";

const agent = new Agent({
  id: "my-agent",
  name: "My Agent",
  instructions: "You are a helpful assistant",
  model: "mastra/openai/gpt-5-mini"
});

Use the same prefix for embedding models that should run through the gateway:

src/mastra/rag/embed.ts

import { ModelRouterEmbeddingModel } from "@mastra/core/llm";

const embedder = new ModelRouterEmbeddingModel("mastra/openai/text-embedding-3-small");

Pass memory.thread and memory.resource when you generate/stream responses to enable Observational Memory:

src/mastra/run.ts

import { weatherAgent } from "./agents/weather-agent";

const memory = {
  thread: "assistant-thread-1",
  resource: "user-42",
};

const result = await weatherAgent.stream("My name is Alex and I prefer concise answers.", {
  memory,
});

for await (const chunk of result.textStream) {
  process.stdout.write(chunk);
}

Configuration

# Use gateway API key
MASTRA_GATEWAY_API_KEY=your-gateway-key

Learn more

• Features
• Models
• Limits
• API Reference
• Examples