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Mastra vs Vellum

Vellum scores higher on the AgentReady, 88/100 against 42/100. They differ on 18 of the 41 signals. Which ones decides whether an agent can adopt them without a person watching.

What each one is

Mastra. Mastra is a TypeScript framework for building AI agents and applications.

Vellum. A personal AI assistant that lives in the secure Vellum Cloud, has its own identity, and actually does things in the world.

Where Vellum is ahead

Vellum passes llms-full.txt / full agent docs, and Mastra does not. That is discover, whether an agent can find the product at all without being told it exists.

It also holds understand: structured api reference, openapi / spec quality, pricing understandable, request examples provided, response examples provided and errors and status codes documented. Mastra misses those.

And on adopt, self-service signup, no mandatory sales call, agent-compatible signup flow, programmatic credential creation, free trial or free allowance, fast time to first request and official python sdk. Mastra misses those.

Finally, on operate, structured, predictable output, machine-readable errors, retry behavior documented and observable execution. Mastra misses those.

What neither does

Both fail authentication documented, limits / constraints documented, idempotency support, rate-limit behavior predictable, agent compatibility verified. If your agent needs any of those, you will be building it yourself either way.

Score, pillar by pillar

The AgentReady splits into four pillars, scored separately, because a product can be easy to find and still impossible to adopt.

Discover. Vellum leads 100 to 93. Mastra misses llms-full.txt / full agent docs; Vellum misses nothing.

Understand is whether an agent can read the docs and work out how the API behaves before calling it. Vellum leads 85 to 15. Mastra misses structured api reference, openapi / spec quality, authentication documented, pricing understandable, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented; Vellum misses authentication documented, limits / constraints documented.

Adopt. Vellum leads 100 to 35. Mastra misses self-service signup, no mandatory sales call, agent-compatible signup flow, programmatic credential creation, free trial or free allowance, fast time to first request, official python sdk; Vellum misses nothing.

Operate. Vellum leads 67 to 24. Mastra misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, observable execution, agent compatibility verified; Vellum misses idempotency support, rate-limit behavior predictable, agent compatibility verified.

Pricing

Mastra does not publish a machine-readable starting price. Vellum starts at $30/mo and has a free tier.

Signal by signal

Which to pick

Vellum clears more of the signals an agent needs, so it is the safer default for unattended use. Full profiles: Mastra and Vellum. Alternatives to each: Mastra, Vellum.

An agent can fetch this as data: POST /v1/compare {"slugs": ["mastra", "vellum"]}