Melious

Access 15 Melious models through Mastra's model router. Authentication is handled automatically using the MELIOUS_API_KEY environment variable.

Learn more in the Melious documentation.

.env

MELIOUS_API_KEY=your-api-key

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: "melious/deepseek-r1-0528"
});

// Generate a response
const response = await agent.generate("Hello!");

// Stream a response
const stream = await agent.stream("Tell me a story");
for await (const chunk of stream) {
  console.log(chunk);
}

note

Mastra uses the OpenAI-compatible /chat/completions endpoint. Some provider-specific features may not be available. Check the Melious documentation for details.

Models

15 available models

Model	Context	Tools	Reasoning	Image	Audio	Video	Input $/1M	Output $/1M
melious/deepseek-r1-0528	164K						$0.70	$3
melious/deepseek-v3.2	164K						$0.35	$0.58
melious/deepseek-v4-flash-0731	1.0M						$0.12	$0.29
melious/deepseek-v4-pro	1.0M						$2	$4
melious/deepseek-v4-pro-0813	1.0M						$1	$3
melious/deepseek-v4.1-flash	1.0M						$0.23	$1
melious/glm-5	203K						$1	$3
melious/glm-5.1	203K						$2	$5
melious/glm-5.2	1.0M						$1	$5
melious/glm-5.3	1.0M						$1	$3
melious/glm-5.3-flash	1.0M						$0.12	$0.46
melious/kimi-k2.5	262K						$0.58	$3
melious/kimi-k2.6	256K						$0.81	$4
melious/kimi-k2.7-code	262K						$0.81	$3
melious/kimi-k3	1.0M						$3	$16

Model availability, capabilities, context windows, and pricing are sourced from models.dev and may change.

Advanced configuration

Custom headers

src/mastra/agents/my-agent.ts

const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "https://api.melious.ai/v1",
    id: "melious/deepseek-r1-0528",
    apiKey: process.env.MELIOUS_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});

Dynamic model selection

src/mastra/agents/my-agent.ts

const agent = new Agent({
  id: "dynamic-agent",
  name: "Dynamic Agent",
  model: ({ requestContext }) => {
    const useAdvanced = requestContext.task === "complex";
    return useAdvanced
      ? "melious/kimi-k3"
      : "melious/deepseek-r1-0528";
  }
});