The agentic developer platform

The world's easiest infrastructure
for engineers who ship with AI.

Mosaic gives you a dedicated Postgres database, S3-compatible storage, auth, realtime, git hosting, and one-command container deploys — all behind a single API key your agent can drive. One platform. One key. Everything your app needs to ship.

The Supabase model, rebuilt for vibe engineers and the agents writing alongside them. Provision a backend in seconds, deploy from git, and let Claude or Codex own the platform end-to-end.
Postgres 17 · pgvector + uuid-ossp 9 runtimes deployed from git {slug}.mosaic.site + custom domains 1 API key. one platform.
Thesis

The backend has been waiting for its iPhone moment.

Most platforms were built for humans clicking dashboards. Mosaic is built for agents — and the engineers shipping with them — to provision, deploy, and operate real production infrastructure with a single API key.

Every project gets its own Postgres database, its own object store, its own git remote, and its own deploy target. No quotas you can't see. No shared multi-tenant tables. No setup wizards.

You — or your agent — make one HTTP call, and the backend exists. The next call, your app is live at {slug}.mosaic.site with SSL.

Capabilities

Everything you'd glue together — in one platform.

Ten primitives. One API. Zero infrastructure to manage. Each one is dedicated per-project, not shared multi-tenant.

02 Storage

S3-compatible object store

Presigned upload & download URLs, per-project bucket isolation, served via MinIO. Drop-in for any S3 SDK.

03 Auth

Magic links & passwords

Built-in end-user authentication — magic links via email plus email/password with Argon2 hashing. No provider to wire up.

04 Realtime

WebSocket subscriptions

Subscribe to row-level changes over Redis pub/sub fan-out. Event filters, column filters, multi-subscriber — all transparent.

05 Git

Hosted git remotes

Every project gets a Gitea remote. Credential-free file push API for agents — write code from a tool call, see it deployed.

06 Deploy

Containers from git

Node, Python, Go, Rust, PHP, Ruby, Java, Static — push to git, container boots. One command. Zero Docker files.

07 Hosting

Static sites + custom domains

Every deploy lives at {slug}.mosaic.site with automatic SSL. Point your own domain — DNS check, cert, route, done.

08 Mail

Bring-your-domain email

Stalwart-backed mailboxes on domains you own — DKIM, SPF, DMARC, IMAP, SMTP. Real inboxes, not transactional one-shots.

09 Agent SDK

Claude Code skill

Install @mosaicsite/claude-skill and Claude reads the live skill spec on every session. Your agent owns the platform.

10 Enterprise

Dedicated nodes

Enterprise tier ships projects to your own hardware — managed containers, in-cluster Postgres, full sovereignty. Same API.

Built for agents

The first backend platform where the agent is the user.

Mosaic was designed from day one to be driven by AI coding assistants — Claude Code, Codex, Cursor, whoever ships next. One header. No SDKs. No console clicks.

One API key. One platform. Everything.

Every Mosaic user gets a single API key on signup. That key opens every primitive on the platform — database, storage, auth, deploys, realtime — over plain HTTPS.

There are no client libraries to install, no provider mocks to wire up, and no auth dance between subsystems. Your agent curls the endpoint and the work is done.

Provision a backend
# Create a project — gets its own DB, storage, git remote curl -X POST https://api.mosaic.site/v1/project/projects \ -H "X-API-Key: $MOSAIC_API_KEY" \ -d '{"name":"my-app"}'
Run a query
curl https://api.mosaic.site/v1/project/{id}/sql \ -H "X-API-Key: $MOSAIC_API_KEY" \ -d '{"query":"SELECT * FROM users","params":[]}'

The skill lives at a URL.

Install @mosaicsite/claude-skill globally and your Claude Code sessions will fetch the live skill spec from api.mosaic.site/skill.md on every load.

When we ship a new endpoint, your agent learns it on the next session. No package upgrades. No drift between platform and prompt.

Install once
# Globally — works in every project npm i -g @mosaicsite/claude-skill # Now Claude Code knows every Mosaic endpoint, # reads your API key from $MOSAIC_API_KEY, # and ships features end-to-end.
Works in Codex too
curl -fsSL https://api.mosaic.site/skill.md \ -o ~/.codex/AGENTS.md

Push code. Get a URL.

Every project comes with its own git remote. Push to main and Mosaic builds a container — picking the runtime from the repo automatically (Node, Python, Go, Rust, PHP, Ruby, Java, Static).

The deploy lives at {slug}.mosaic.site with SSL the moment the build finishes. Want your own domain? One API call, one DNS record, done.

Deploy
# Push files via API (no SSH key dance) curl -X POST https://api.mosaic.site/v1/project/{id}/git/files \ -H "X-API-Key: $MOSAIC_API_KEY" \ -d @payload.json # Trigger a deploy from main curl -X POST https://api.mosaic.site/v1/project/{id}/deploy
Attach a custom domain
curl -X POST .../{id}/domains \ -d '{"domain":"app.example.com"}'
The Stack

Boring infrastructure. Modern primitives.

No exotic services. No vendor lock-in. Just battle-tested open source, configured properly, exposed over one API.

Primitive Engine What it gives you Isolation
DatabasePostgreSQL 17 + PgBouncerFull SQL over HTTP, pgvector for embeddings, uuid-ossp + pgcrypto built inper-project
Object storageMinIO (S3 API)Presigned upload/download URLs, public + private bucketsper-project
Cache & pubsubRedis 7 — 32 GBPowers realtime fan-out, session store, ephemeral stateper-project namespace
AuthArgon2 + JWT + ResendMagic links, password auth, password reset, verified emailper-project
Git hostingGiteaGit remote per project, credential-free file push API for agentsper-project repo
ComputeIncus containersNode, Python, Go, Rust, PHP, Ruby, Java, Static — runtime auto-detectedper-deploy
EdgeTraefik v3Automatic SSL, custom domains, sub-second routing changesplatform
MailStalwartBring-your-domain mailboxes — IMAP, SMTP, DKIM, SPF, DMARCper-domain
Control planeFastAPI + asyncpgThe one API you call. Async, parameterized, one key.platform
Plans

Free to start. Honest pricing as you grow.

Every tier gets the full platform — same API, same primitives. Limits scale; capabilities don't.

Free

Trial

$0 / forever

Kick the tires. Build a prototype. See if Mosaic fits.

  • 2 projects
  • 500 MB DB · 1 GB storage
  • SQL, storage, auth, git, deploy
  • Community support
Starter

Starter

$10 / mo

For solo builders shipping side projects with their AI.

  • 5 projects
  • 2 GB DB · 10 GB storage
  • Custom domains & SSL
  • Email support
Enterprise

Enterprise

Custom

Dedicated nodes, your hardware, full data sovereignty.

  • Dedicated compute + DB
  • Managed containers via API
  • SSO & audit logs
  • SLA + named support
Start shipping

One install. Your agent owns the backend.

Install the skill, set your key, ship the feature. Mosaic does the infrastructure. Your AI does the rest.

$npm install -g @mosaicsite/claude-skill