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Braintrust vs Vellum

Vellum scores higher on the AgentReady, 88/100 against 55/100. They differ on 12 of the 41 signals. Which ones decides whether an agent can adopt them without a person watching.

What each one is

Braintrust. Braintrust is the active observability platform for instrumenting, understanding, and improving agents.

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 mcp discoverable, and Braintrust 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, request examples provided, response examples provided and errors and status codes documented. Braintrust misses those.

And on adopt, no mandatory sales call, programmatic credential creation and mcp integration available. Braintrust misses those.

Finally, on operate, machine-readable errors and retry behavior documented. Braintrust 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 80. Braintrust misses llms-full.txt / full agent docs, mcp discoverable; 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 23. Braintrust misses structured api reference, openapi / spec quality, authentication documented, 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 67. Braintrust misses no mandatory sales call, programmatic credential creation, mcp integration available; Vellum misses nothing.

Operate. Vellum leads 67 to 50. Braintrust misses machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified; Vellum misses idempotency support, rate-limit behavior predictable, agent compatibility verified.

Pricing

Braintrust starts at $0/mo and has a free tier. 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: Braintrust and Vellum. Alternatives to each: Braintrust, Vellum.

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