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Better Auth vs Permit.io

Permit.io scores higher on the AgentReady, 79/100 against 57/100. They differ on 15 of the 41 signals. Which ones decides whether an agent can adopt them without a person watching.

What each one is

Better Auth. A framework-agnostic, universal authentication and authorization framework for TypeScript.

Permit.io. Permissions for the AI era.

Where Better Auth is ahead

Better Auth passes authentication documented and limits / constraints documented, and Permit.io does not. That is understand, whether an agent can read the docs and work out how the API behaves before calling it.

It also holds adopt: self-service signup. Permit.io misses it.

Where Permit.io is ahead

Permit.io passes clear canonical domain and llms-full.txt / full agent docs, and Better Auth does not. That is discover, whether an agent can find the product at all without being told it exists.

It also holds understand: openapi / spec quality, request examples provided, response examples provided and errors and status codes documented. Better Auth misses those.

And on adopt, agent-compatible signup flow, programmatic credential creation and copyable quickstart. Better Auth misses those.

Finally, on operate, structured, predictable output, machine-readable errors and observable execution. Better Auth misses those.

What neither does

Both fail no mandatory sales call, fast time to first request, retry behavior 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. Permit.io leads 100 to 87. Better Auth misses clear canonical domain, llms-full.txt / full agent docs; Permit.io misses nothing.

Understand. Permit.io leads 85 to 54. Better Auth misses openapi / spec quality, request examples provided, response examples provided, errors and status codes documented; Permit.io misses authentication documented, limits / constraints documented.

Adopt. Permit.io leads 70 to 62. Better Auth misses no mandatory sales call, agent-compatible signup flow, programmatic credential creation, fast time to first request, copyable quickstart; Permit.io misses self-service signup, no mandatory sales call, fast time to first request.

Operate is whether an agent can run against it in production and recover when a call fails. Permit.io leads 59 to 24. Better Auth misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, observable execution, agent compatibility verified; Permit.io misses retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified.

Pricing

Better Auth starts at $0/month and has a free tier. Permit.io does not publish one and has a free tier.

Signal by signal

Which to pick

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

An agent can fetch this as data: POST /v1/compare {"slugs": ["better-auth", "permit"]}