OpenAI Responses API vs Mastra
A side-by-side comparison to help you choose the right tool.
87
OpenAI Responses API scores higher overall (87/100)
But the best choice depends on your specific needs. Compare below.
| Feature | OpenAI Responses API | Mastra |
|---|---|---|
| Our score | 87 | 80 |
| Pricing | Usage-based API pricing; costs depend on the models and tools you use. | Fully open source under MIT license. No cloud fees. Self-hosted on your own infrastructure. |
| Free plan | No | Yes |
| Best for | Product teams building assistants or agents on OpenAI, Developers migrating from older endpoint patterns, Apps that need streaming and tool invocation in one API | TypeScript and Node.js developers who want a structured, production-ready agent framework, Teams building internal AI copilots or customer-facing assistants with full code control, Startups embedding AI capabilities into products that need evals and tracing from day one |
| Platforms | api | api, web |
| API | Yes | Yes |
| Languages | en | en |
| Pros |
|
|
| Cons |
|
|
| Visit site | Visit site |
- Pricing
- Usage-based API pricing; costs depend on the models and tools you use.
- Free plan
- No
- Best for
- Product teams building assistants or agents on OpenAI, Developers migrating from older endpoint patterns, Apps that need streaming and tool invocation in one API
- Platforms
- api
- API
- Yes
- Languages
- en
Mastra
80
- Pricing
- Fully open source under MIT license. No cloud fees. Self-hosted on your own infrastructure.
- Free plan
- Yes
- Best for
- TypeScript and Node.js developers who want a structured, production-ready agent framework, Teams building internal AI copilots or customer-facing assistants with full code control, Startups embedding AI capabilities into products that need evals and tracing from day one
- Platforms
- api, web
- API
- Yes
- Languages
- en
87Choose OpenAI Responses API if:
- You are Product teams building assistants or agents on OpenAI
- You are Developers migrating from older endpoint patterns
- You are Apps that need streaming and tool invocation in one API
80Choose Mastra if:
- You are TypeScript and Node.js developers who want a structured, production-ready agent framework
- You are Teams building internal AI copilots or customer-facing assistants with full code control
- You are Startups embedding AI capabilities into products that need evals and tracing from day one
- You want to start free
FAQ
- What is the difference between OpenAI Responses API and Mastra?
- OpenAI Responses API is openai's newer response-oriented api surface for building assistants and agents with streaming, tools, and model control. Mastra is open-source typescript framework for building production-ready ai agents and multi-step workflows, with a local studio ui, typed zod schemas, built-in evals, and support for suspend/resume human-in-the-loop flows.
- Which is cheaper, OpenAI Responses API or Mastra?
- OpenAI Responses API: Usage-based API pricing; costs depend on the models and tools you use.. Mastra: Fully open source under MIT license. No cloud fees. Self-hosted on your own infrastructure.. Mastra has a free plan.
- Who is OpenAI Responses API best for?
- OpenAI Responses API is best for Product teams building assistants or agents on OpenAI, Developers migrating from older endpoint patterns, Apps that need streaming and tool invocation in one API.
- Who is Mastra best for?
- Mastra is best for TypeScript and Node.js developers who want a structured, production-ready agent framework, Teams building internal AI copilots or customer-facing assistants with full code control, Startups embedding AI capabilities into products that need evals and tracing from day one.