Weights & Biases

Access 25 Weights & Biases models through Mastra's model router. Authentication is handled automatically using the WANDB_API_KEY environment variable.

Learn more in the Weights & Biases documentation.

.env

WANDB_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: "wandb/JetBrains/Mellum2-12B-A2.5B-Instruct"
});

// 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);
}

info

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

Models

25 available models

Model	Context	Tools	Reasoning	Image	Audio	Video	Input $/1M	Output $/1M
wandb/deepseek-ai/DeepSeek-V3.1	161K						$0.55	$2
wandb/deepseek-ai/DeepSeek-V4-Flash	1.0M						$0.14	$0.28
wandb/deepseek-ai/DeepSeek-V4-Pro	1.0M						$2	$3
wandb/google/gemma-4-31B-it	262K						$0.12	$0.35
wandb/ibm-granite/granite-4.1-8b	131K						$0.05	$0.10
wandb/JetBrains/Mellum2-12B-A2.5B-Instruct	131K						$0.05	$0.10
wandb/meta-llama/Llama-3.1-70B-Instruct	128K						$0.80	$0.80
wandb/meta-llama/Llama-3.1-8B-Instruct	128K						$0.22	$0.22
wandb/meta-llama/Llama-3.3-70B-Instruct	128K						$0.71	$0.71
wandb/MiniMaxAI/MiniMax-M2.5	197K						$0.30	$1
wandb/moonshotai/Kimi-K2.5	262K						$0.60	$3
wandb/moonshotai/Kimi-K2.6	262K						$0.95	$4
wandb/moonshotai/Kimi-K2.7-Code	262K						$0.94	$4
wandb/nvidia/NVIDIA-Nemotron-3-Super-120B-A12B-FP8	262K						$0.20	$0.80
wandb/nvidia/NVIDIA-Nemotron-3-Ultra-550B-A55B	262K						$0.75	$3
wandb/openai/gpt-oss-120b	131K						$0.04	$0.14
wandb/openai/gpt-oss-20b	131K						$0.03	$0.13
wandb/OpenPipe/Qwen3-14B-Instruct	33K						$0.05	$0.22
wandb/Qwen/Qwen3-30B-A3B-Instruct-2507	262K						$0.10	$0.30
wandb/Qwen/Qwen3-Coder-480B-A35B-Instruct	262K						$1	$2
wandb/Qwen/Qwen3.5-35B-A3B	262K						$0.25	$1
wandb/Qwen/Qwen3.6-27B	262K						$0.60	$4
wandb/Qwen/Qwen3.6-35B-A3B	262K						$0.25	$1
wandb/zai-org/GLM-5.1	203K						$1	$4
wandb/zai-org/GLM-5.2	262K						$1	$4

Advanced configuration

Custom headers

src/mastra/agents/my-agent.ts

const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "https://api.inference.wandb.ai/v1",
    id: "wandb/JetBrains/Mellum2-12B-A2.5B-Instruct",
    apiKey: process.env.WANDB_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
      ? "wandb/zai-org/GLM-5.2"
      : "wandb/JetBrains/Mellum2-12B-A2.5B-Instruct";
  }
});