Mastra - Phaseo Docs

Mastra works with AI SDK providers, so the shortest path is to create an OpenAI-compatible provider that points at Phaseo.

Install

npm install @mastra/core @ai-sdk/openai ai

Configure an agent

import { Agent } from "@mastra/core/agent";
import { createOpenAI } from "@ai-sdk/openai";

const phaseo = createOpenAI({
	apiKey: process.env.PHASEO_API_KEY,
	baseURL: "https://api.phaseo.app/v1",
	compatibility: "compatible",
});

export const agent = new Agent({
	name: "support-agent",
	instructions: "Answer in two short paragraphs.",
	model: phaseo("openai/gpt-5-nano"),
});

Notes

Use the base URL only, not /chat/completions or /responses.
Mastra agent behavior depends on the AI SDK provider path. Test tools and streaming before production.
Use Phaseo routing controls at the request level or through presets when you need provider preferences.

Last modified on July 26, 2026