An open source Better Auth alternative for AI agents
theAuthvsBetter Auth
Both are MIT auth libraries you run yourself. Better Auth has the larger community and plugin set; theAuth builds agent identity into its core and adds Go and Python SDKs.
Last verified: 2026-10-07. Open source library against an MIT library.
You build a TypeScript app, want a large community and the broad plugin set: organization, SSO, SCIM, passkey and API key.
You want to stay in the ecosystem most TypeScript teams already know, with 30.2k GitHub stars when we checked.
You want its Agent Auth plugin and accept that its docs describe it as under heavy development and not yet stable.
Choose theAuth if
Agent identity is a core requirement: an owner, delegation depth limits, per-agent budgets and audit built into the library.
Your backend is Go or Python as well as TypeScript, and you want one model across all three.
You want an OAuth 2.1 server for MCP together with the Go RFC set (token exchange, DPoP, PAR, JAR, CIBA) and a resource-server module.
theAuth is an open source Better Auth alternative for teams that want agent identity in the same library as human sign-in. It is not the right pick for every team, and the first column says so.
theAuth vs Better Auth feature comparison
Feature comparison of Better Auth and theAuth
Feature
Better Auth
theAuth
Source license
Yes, MIT
Yes, MIT
Self-hostable
Yes, Yes, runs in your app
Yes, Yes, on your own database
Language
TypeScript
TypeScript core, plus Go and Python SDKs
OAuth 2.1 authorization server for MCP
Yes, Yes, MCP plugin with PKCE and RFC 9728 metadata
Yes, Yes, built in
Dynamic client registration
Partial or different, Available but never enabled implicitly; CIMD recommended
Yes, RFC 7591 supported; CIMD in the Go module
Agent identity
Partial or different, Agent Auth plugin: delegated and autonomous agents, capabilities; docs say not yet stable
Yes, Device authorization and CIBA in the Agent Auth plugin
Yes, CIBA-style approval for sensitive tool calls
Per-agent budgets
Partial or different, Not found in the Better Auth docs we checked
Yes, Budget policies
Organizations, SSO and SCIM
Yes, Plugins for organization, SSO and SCIM
Yes, Organizations with RBAC, SAML 2.0, OIDC SSO, SCIM 2.0
Check mark: yes. Dash: partial, different, or not found in the docs we checked. Cross: no. Claims about Better Auth are from its own public docs (see Sources); theAuth rows are from its repositories.
01
Better Auth alternative for AI agents: identity and delegation
A plugin on one side, the core model on the other.
Better Auth
Better Auth ships an Agent Auth plugin that implements the Agent Auth Protocol: agents register through discovery documents, request approval by device authorization or CIBA, and run narrowly scoped capabilities with short-lived signed JWTs, in delegated or autonomous mode. An onEvent hook reports lifecycle events for audit. Its docs say the plugin is under heavy development and not yet stable.
theAuth
theAuth models an agent as an identity with an owner, a cryptographic bearer token (kv_...), wildcard permissions such as mcp:github:*, and delegation chains with configurable depth limits. On top of that sit budget policies per agent, trust scoring, CIBA-style approval for sensitive tool calls, and a full audit trail of every agent action. Read the agents guide and delegation docs.
02
MCP OAuth 2.1 support
Both can be the authorization server.
Better Auth
Better Auth's MCP plugin lets your app act as an OAuth authorization server and protected resource for MCP clients. It serves RFC 9728 metadata, uses PKCE, can enforce DPoP, requires the JWT plugin, and treats dynamic client registration as opt-in because MCP deprecates it in favor of CIMD.
theAuth
theAuth ships an OAuth 2.1 authorization server for MCP: PKCE S256, RFC 9728 protected resource metadata, RFC 8707 resource indicators, RFC 8414 server metadata and RFC 7591 dynamic client registration. The Go module adds RFC 8693 token exchange, DPoP, PAR, JAR, CIBA, CIMD per the MCP spec of 2025-11-25 and refresh token rotation with family revocation. See the MCP guide.
03
Self-hosting and data ownership
Same ownership model.
Better Auth
Better Auth is a library that runs inside your application against your own database, so user data stays in your infrastructure. On this point the two are the same. The difference is language reach: Better Auth is built for TypeScript, while theAuth also ships Go and Python SDKs.
theAuth
theAuth is MIT licensed and runs against your own database: SQLite, PostgreSQL, MySQL or Cloudflare D1 in TypeScript, and Postgres, MySQL or in-memory storage in Go. Users, sessions, tokens and audit records stay in storage you control. A hosted theAuth Cloud is in early access for teams that would rather not run it.
04
Licensing and cost model
Two MIT libraries.
Better Auth
Better Auth is MIT licensed and free to use. As with theAuth, you pay for your own database, compute and the time to run it. There is no license difference to weigh, so decide on features and fit.
theAuth
The library is free under the MIT license. Your costs are the database, the compute and the engineering time to operate it. theAuth Cloud is in early access and has no published prices.
05
Edge runtimes
Check the matrix for your platform.
Better Auth
We did not verify Better Auth's edge runtime support from its docs, so we make no claim either way. Check its documentation for Cloudflare Workers, Deno or Bun before you commit.
theAuth
The TypeScript core runs on Cloudflare Workers, Deno and Bun without code changes, with three runtime dependencies: drizzle-orm, jose and zod. Adapters cover Next.js, SvelteKit, Nuxt, Hono, Express, Fastify, Astro, NestJS, SolidStart and TanStack Start.
Migrating from Better Auth to theAuth
theAuth has a Better Auth migration guide with a concepts map, code diffs, data migration SQL and a rollback strategy. If you already use Better Auth's agent plugin there is a separate agent plugin migration guide covering the delegation chain shape and cascading revocation.
Is theAuth a Better Auth alternative for AI agents?
Yes, if agent identity is central to your design. Both are MIT libraries you run yourself. Better Auth offers an Agent Auth plugin that its docs call not yet stable, while theAuth builds agent identity, delegation limits, budgets and audit into the core and adds Go and Python SDKs.
What does Better Auth do better than theAuth?
It has the larger community, with 30.2k GitHub stars when we checked, and a wide plugin set that includes organization, SSO, SCIM, passkey and API key. If you only need human auth in a TypeScript app, it is a strong choice.
Does Better Auth support MCP OAuth 2.1?
Yes. Its MCP plugin lets your app act as an OAuth authorization server for MCP clients, with PKCE, RFC 9728 metadata and optional DPoP. theAuth also includes an MCP OAuth 2.1 authorization server.
Are Better Auth and theAuth both open source?
Yes. Both are MIT licensed and both run in your own infrastructure against your own database.
Can I migrate from Better Auth to theAuth?
Yes. theAuth documents a migration from Better Auth, and a separate one for the Better Auth agent plugin, with concept maps, code diffs and a rollback plan.
Sources
Last verified: 2026-10-07. Competitor facts come from the public pages below; plans and prices change, so confirm there.
Install the package, create an agent with scoped permissions, and read its first audit record. The core runs on Postgres, SQLite, MySQL or D1, and the Go module needs a single go get.