Supabase Self-Hosted — Packing a BaaS into One Postgres Pot

Supabase appeared in 2020 with the slogan "open source Firebase." If Firebase is one giant managed box with its own NoSQL · Auth · Storage, Supabase took the path of placing Postgres at the center and stacking small components on top. Managed (supabase.com) and self-hosted run on the same components.

1. About Supabase

Supabase's "backend service" is in fact a single Postgres + a bundle of microservices in front of it. None of the components keeps its own separate database.

• The Auth user table, Storage object metadata, and Realtime change events all live in different schemas of the same Postgres (auth · storage · _realtime · _supabase · _analytics).

That is why a single SQL query can deal with permissions, storage, and authentication at once, and why the deploy unit for self-hosted is simple.

2. The 14 components

13~14 containers in one bundle. The official docker-compose is the answer — basing your own setup on the compose under supabase/supabase/docker/ is far less error-prone than authoring from scratch.

3. JWT secret model — the most common stuck point

Supabase's Auth and PostgREST trust only JWTs signed with the same JWT_SECRET. 90% of self-hosted setup pitfalls live here.

Three variables must remain consistent:

• JWT_SECRET — A 32+ character random string. The same value across all component env vars.
• ANON_KEY — A {role: "anon"} JWT signed with JWT_SECRET.
• SERVICE_ROLE_KEY — A {role: "service_role"} JWT signed with JWT_SECRET.

The demo keys in the official .env.example are signed with a fixed secret (your-super-secret-jwt-token-with-at-least-32-characters-long). Changing only JWT_SECRET while leaving the keys means immediate 401 · 403 on every call.

node -e '
const c = require("crypto");
const s = "put new JWT_SECRET here";
const sign = (p) => {
  const h = Buffer.from(JSON.stringify({alg:"HS256",typ:"JWT"})).toString("base64url");
  const b = Buffer.from(JSON.stringify(p)).toString("base64url");
  return `${h}.${b}.${c.createHmac("sha256",s).update(`${h}.${b}`).digest("base64url")}`;
};
const iat = Math.floor(Date.now()/1000), exp = iat + 60*60*24*365*5;
console.log("ANON_KEY=" + sign({role:"anon", iss:"supabase-demo", iat, exp}));
console.log("SERVICE_ROLE_KEY=" + sign({role:"service_role", iss:"supabase-demo", iat, exp}));
'

4. Storage — the value of file mode

STORAGE_BACKEND selects the backend:

• STORAGE_BACKEND=s3 — S3-compatible endpoint (managed standard). Self-hosted needs an extra S3 like MinIO.
• STORAGE_BACKEND=file — Stores files directly on container volumes. Zero external dependency — the simplest option for self-hosted.

Managed Supabase uses s3 mode, but for self-hosted simplicity, file is the answer. publicUrl, signed URLs, RLS, and imgproxy transforms all behave identically.

5. Auth + Inbucket — receiving mail to disk

GoTrue sends mail over SMTP for sign-up and password reset. With no external SMTP, the standard self-hosted pattern is to also bring up a dev SMTP server like Inbucket.

auth:
  environment:
    GOTRUE_SMTP_HOST: inbucket
    GOTRUE_SMTP_PORT: 2500

inbucket:
  image: inbucket/inbucket
  ports:
    - "9000:9000"   # Web UI
    - "2500:2500"   # SMTP

After signing up, opening http://localhost:9000 shows the "Confirm Your Email" message GoTrue sent.

6. Kong — the single entry point

Kong's role:

1. Externally only one Kong port (typically 8000 or 54321) is visible.
2. Internal per-path routing (/auth/v1/* → auth, /rest/v1/* → rest, /storage/v1/* → storage, /realtime/v1/* → realtime, /functions/v1/* → functions).
3. Distinguishes anon · service_role via apikey/JWT headers.

Kong's kong.yml is declarative config. Env-var placeholders ($ANON_KEY) are substituted by an awk-based container entrypoint. When self-hosted Kong dies with /entrypoint.sh: No such file or directory, the cause is usually the kong image bumping versions and moving the entrypoint to /docker-entrypoint.sh (kong:3.x and later).

7. Postgres — why supabase/postgres matters

Standard images like postgres:15-alpine will not run self-hosted Supabase. Required extensions:

• pgvector — embeddings.
• pg_graphql — auto-generated GraphQL.
• pg_cron — scheduled jobs.
• pg_net — HTTP calls from inside the DB (webhooks).
• pgaudit — audit logs.
• pg_stat_statements.

The supabase/postgres image ships these prebuilt. Installing them onto a standard image causes Realtime · Auth init failures.

8. Frequent stuck points

9. Calling with supabase-js

import { createClient } from "@supabase/supabase-js";

const supabase = createClient(
  "http://localhost:54321",
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
);

// Auth
await supabase.auth.signUp({ email: "x@local.dev", password: "1234" });

// REST (auto-generated)
const { data } = await supabase.from("posts").select("*").limit(10);

// Storage
await supabase.storage.from("bucket").upload("k.png", file);

// Realtime
supabase
  .channel("posts")
  .on("postgres_changes", { event: "*", schema: "public", table: "posts" }, console.log)
  .subscribe();

// Edge Function
await supabase.functions.invoke("hello", { body: { name: "world" } });

Swapping just one URL between managed and self-hosted runs the same code on both. That is Supabase's biggest promise.

10. Limitations

Memory footprint of 14 containers — idle ~3 GB. On tight laptops, disable analytics · vector, or use the managed offering.

Fast-moving version matrix — components have specific compatible combinations. Following SHA-pinned tags from the official compose is safest.

CDN · domain handling — Storage publicUrl can return container-internal hostnames, so production runs Caddy reverse proxy + SUPABASE_PUBLIC_URL env var for the external domain.

Backup — pg_dump is effectively the backup. Also preserve the storage file backend (/var/lib/storage).

Closing thoughts

Self-hosted Supabase is a bundle of 14 containers, but the data lives in one Postgres. JWT secret consistency + Storage file mode + Inbucket make the most solid shape with zero external dependency. Code compatibility between managed and self-hosted comes down to one URL — accepting 14 containers for that value is the essence of self-hosted.

Next

• firebase-emulator
• api-mocking-wiremock

Supabase official · Self-hosting guide · supabase-js · GoTrue · PostgREST · Realtime · Storage API · Inbucket for reference.