Kelta compared

The open-source application platform your AI agents can actually operate — schema, flows, and approvals over an API and an MCP server.

Supabase, Appwrite, PocketBase and Directus are good projects, and each is the better choice for some teams. Every competitor entry below links to that project's own documentation; check it before you decide.

	Kelta	Supabase	Appwrite	PocketBase	Directus
Self-hosting	Docker Compose for evaluation, Kubernetes for production; needs PostgreSQL, Redis, NATS and Cerbos alongside the services	Docker Compose; a self-hosted install is a single project	Docker install with a setup wizard	One executable with embedded SQLite	Docker, over Postgres, MySQL, SQLite and other SQL databases
License	AGPLv3	Apache 2.0	BSD 3-Clause	MIT	Monospace Sustainable Core License 1.0 — read the license terms
Data model	Metadata-driven: collections and fields are defined at runtime, each collection backed by a physical PostgreSQL table and served as JSON:API	SQL-first: you design tables directly in a Postgres database	Databases of tables with typed columns and rows, plus document and vector databases	Collections backed by SQLite tables generated from their fields	Database-first: collections and fields map to tables and columns in your own SQL database
Multi-tenancy	Built in: tenants resolved by slug or custom domain, isolated by PostgreSQL row-level security	Not a built-in tenant model; you write Postgres row-level security policies	Modelled with Teams and team permissions, one team per tenant	Not built in; access is expressed per collection with API rules	Not built in; roles and access policies
MCP / agent support	Hosted MCP server per tenant with admin (schema, flows, layouts) and user (records, search, approvals) toolsets	MCP server for working with your Supabase projects	Hosted MCP server for its API and docs	— (none in its docs)	MCP server (Directus v11.12+)
Auth	Built-in OIDC provider, OIDC and SAML single sign-on, TOTP and SMS MFA, personal access tokens	Supabase Auth	Email/password, phone, magic URL, email OTP, OAuth2, anonymous, MFA	Password, OTP, OAuth2 and MFA	OpenID, OAuth 2.0, LDAP and SAML single sign-on
Authorization	Profiles, groups and record sharing, combined most-permissive-wins and evaluated by Cerbos policies generated from tenant metadata for every route, record and field	Postgres row-level security policies you write in SQL	Per-resource permissions granted to users, teams and roles	API rules: per-collection filter expressions for each action; superusers bypass them	Roles and access policies with per-collection permissions
Realtime	WebSocket record-change events and record presence	Broadcast, Presence and Postgres Changes	Realtime API subscriptions	Realtime subscriptions over server-sent events	WebSocket Realtime API, off by default when self-hosted
File storage	Record attachments on S3-compatible object storage	S3-compatible Storage with resumable uploads	Storage buckets	Local filesystem by default, or S3-compatible	Local, S3, GCS, Azure, Cloudinary and Supabase storage adapters
Admin UI	Admin console for builders plus an end-user app that renders what they build	Studio dashboard	Appwrite Console	Built-in superusers dashboard	Data Studio app for content, files, users and dashboards
Maturity / community	Young project with a small community; some capabilities are documented as partial	Established project with a large open-source community	Established project with a large open-source community	Pre-1.0; backward compatibility is not guaranteed before v1.0.0	Established project with a large open-source community

Checked against each project's documentation in October 2026. Projects move quickly; their docs are the source of truth.

Where they win

Supabase

Supabase is a real Postgres database with the Postgres ecosystem behind it — extensions, tooling and SQL you already know. Its hosted platform runs that database, auth, storage and realtime for you, so there is no infrastructure to operate. If you want a managed Postgres backend today, Supabase is the stronger choice.

Postgres extensions Hosted platform

Appwrite

Appwrite has the broadest SDK coverage of the four: client SDKs for Web, Flutter, Apple, Android and React Native, and server SDKs across Node.js, Python, Dart, PHP, Ruby, .NET, Go, Swift, Kotlin and Rust. If your team ships native mobile apps in several languages, Appwrite meets you where you are.

Appwrite SDKs

PocketBase

PocketBase is a single binary. Download it, run it, and you have a database, auth, file storage, realtime and a dashboard with nothing else to install. Kelta needs PostgreSQL, Redis, NATS and Cerbos next to its own services; for a small app or a prototype, PocketBase is far less to run.

PocketBase introduction

Directus

Directus has the most polished admin UI here. Its Data Studio gives non-technical teams a finished app for content, files, users and dashboards, and it can sit on top of an existing SQL database. If your main need is a back office over data you already have, Directus is the better fit.

Directus Data Studio

Where Kelta fits

Choose Kelta when you need tenants as a first-class concept and want AI agents to change the application itself — collections, fields, flows and approvals — through the MCP server, under the same permissions as a person. Kelta is young: expect a smaller community and rougher edges than any of the projects above. See the roadmap for what is shipped and what is not.