Better Auth vs Clerk
Better Auth scores higher on the AgentReady, 57/100 against 48/100. They differ on 10 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.
Clerk. Clerk provides full-stack authentication and user management with products such as Organizations, Billing, and more.
Where Better Auth is ahead
Better Auth passes search discoverable, and Clerk 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, pricing understandable and limits / constraints documented. Clerk misses those.
And on adopt, self-service signup and free trial or free allowance. Clerk misses those.
Where Clerk is ahead
Clerk 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 adopt: copyable quickstart. Better Auth misses it.
And on operate, observable execution. Better Auth misses it.
What neither does
Both fail openapi / spec quality, request examples provided, response examples provided, errors and status codes documented, no mandatory sales call, agent-compatible signup flow, programmatic credential creation, fast time to first request, structured, predictable output, machine-readable errors, 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. Both sit at 87/100 here. Better Auth misses clear canonical domain, llms-full.txt / full agent docs; Clerk misses search discoverable.
Understand is whether an agent can read the docs and work out how the API behaves before calling it. Better Auth leads 54 to 23. Better Auth misses openapi / spec quality, request examples provided, response examples provided, errors and status codes documented; Clerk misses structured api reference, openapi / spec quality, pricing understandable, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented.
Adopt. Better Auth leads 62 to 48. Better Auth misses no mandatory sales call, agent-compatible signup flow, programmatic credential creation, fast time to first request, copyable quickstart; Clerk 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.
Operate. Clerk leads 35 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; Clerk misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified.
Pricing
Better Auth starts at $0/month and has a free tier. Clerk does not publish one.
| Better Auth plans | Clerk plans |
|---|---|
| Starter $0/month | - |
| Pro $20/month | - |
| Enterprise Custom | - |
Signal by signal
| Signal | Better Auth | Clerk |
|---|---|---|
| AgentReady | 57 | 48 |
| Discovery | 87 | 87 |
| Understanding | 54 | 23 |
| Adoption | 62 | 48 |
| Operability | 24 | 35 |
| Public API | Yes | Yes |
| MCP server | Yes | Yes |
| OpenAPI spec | Yes | Unknown |
| CLI | Yes | Yes |
| llms.txt | Yes | Yes |
| Self-serve signup | Yes | Unknown |
| Free tier | Yes | Unknown |
Which to pick
Better Auth clears more of the signals an agent needs, so it is the safer default for unattended use. Full profiles: Better Auth and Clerk. Alternatives to each: Better Auth, Clerk.
An agent can fetch this as data: POST /v1/compare {"slugs": ["better-auth", "clerk"]}