OpenAI

Access 31 OpenAI models through Mastra's model router. Authentication is handled automatically using the OPENAI_API_KEY environment variable.

Learn more in the OpenAI documentation.

OPENAI_API_KEY=your-api-key

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

const agent = new Agent({
  name: "my-agent",
  instructions: "You are a helpful assistant",
  model: "openai/codex-mini-latest"
});

// 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);
}

Models

31 available models

Model	Context	Tools	Reasoning	Image	Audio	Video	Input $/1M	Output $/1M
openai/codex-mini-latest	200K						$2	$6
openai/gpt-3.5-turbo	16K						$0.50	$2
openai/gpt-4	8K						$30	$60
openai/gpt-4-turbo	128K						$10	$30
openai/gpt-4.1	1.0M						$2	$8
openai/gpt-4.1-mini	1.0M						$0.40	$2
openai/gpt-4.1-nano	1.0M						$0.10	$0.40
openai/gpt-4o	128K						$3	$10
openai/gpt-4o-2024-05-13	128K						$5	$15
openai/gpt-4o-2024-08-06	128K						$3	$10
openai/gpt-4o-2024-11-20	128K						$3	$10
openai/gpt-4o-mini	128K						$0.15	$0.60
openai/gpt-5	400K						$1	$10
openai/gpt-5-chat-latest	400K						$1	$10
openai/gpt-5-codex	400K						$1	$10
openai/gpt-5-mini	400K						$0.25	$2
openai/gpt-5-nano	400K						$0.05	$0.40
openai/gpt-5-pro	400K						$15	$120
openai/o1	200K						$15	$60
openai/o1-mini	128K						$1	$4
openai/o1-preview	128K						$15	$60
openai/o1-pro	200K						$150	$600
openai/o3	200K						$2	$8
openai/o3-deep-research	200K						$10	$40
openai/o3-mini	200K						$1	$4
openai/o3-pro	200K						$20	$80
openai/o4-mini	200K						$1	$4
openai/o4-mini-deep-research	200K						$2	$8
openai/text-embedding-3-large	8K						$0.13	—
openai/text-embedding-3-small	8K						$0.02	—
openai/text-embedding-ada-002	8K						$0.10	—

Advanced Configuration

Custom Headers

const agent = new Agent({
  name: "custom-agent",
  model: {
    id: "openai/codex-mini-latest",
    apiKey: process.env.OPENAI_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});

Dynamic Model Selection

const agent = new Agent({
  name: "dynamic-agent",
  model: ({ runtimeContext }) => {
    const useAdvanced = runtimeContext.task === "complex";
    return useAdvanced
      ? "openai/text-embedding-ada-002"
      : "openai/codex-mini-latest";
  }
});

Provider Options

OpenAI supports the following provider-specific options via the providerOptions parameter:

const response = await agent.generate("Hello!", {
  providerOptions: {
    openai: {
      // See available options in the table below
    }
  }
});

Available Options

include?:

("file_search_call.results" | "message.output_text.logprobs" | "reasoning.encrypted_content")[] | null | undefined

instructions?:

string | null | undefined

logprobs?:

number | boolean | undefined

maxToolCalls?:

number | null | undefined

metadata?:

any

parallelToolCalls?:

boolean | null | undefined

previousResponseId?:

string | null | undefined

promptCacheKey?:

string | null | undefined

reasoningEffort?:

string | null | undefined

reasoningSummary?:

string | null | undefined

safetyIdentifier?:

string | null | undefined

serviceTier?:

"default" | "auto" | "flex" | "priority" | null | undefined

store?:

boolean | null | undefined

strictJsonSchema?:

boolean | null | undefined

textVerbosity?:

"low" | "medium" | "high" | null | undefined

truncation?:

"auto" | "disabled" | null | undefined

user?:

string | null | undefined

Direct Provider Installation

This provider can also be installed directly as a standalone package, which can be used instead of the Mastra model router string. View the package documentation for more details.

npm install @ai-sdk/openai

For detailed provider-specific documentation, see the AI SDK OpenAI provider docs.