Drobek

io.github.freemav0.6.0Updated Sep 29, 2026

Build, preview, version and publish small browser apps from coding agents over MCP.

VerifiedStreamable HTTPWeb executableDeveloper ToolsBrowser Automation

Overview

AI-generated overview

Lets a coding agent build, preview, version and publish small browser apps on a Drobek hosting instance.

What it does
Drobek is an open-source hosting platform for small web apps built by an AI agent. Over MCP the agent calls tools such as create_app, write_files, read_file, publish and restore_version: it writes app sources into a workspace, the server compiles them with esbuild and returns compile errors in the same response, and each successful compile appears on a preview host. Publishing moves a pointer to an immutable version. Platform modules add sign-in, data collections, forms, e-mail, uploads and an SSRF-guarded proxy for external APIs.
When to use it
Use it when you want an assistant to turn a small idea into a working, shareable browser app without you setting up a project, build pipeline or hosting. It suits prototypes, internal tools and small public apps that need sign-in, stored records, forms or uploads. It is not meant for arbitrary server-side code or per-app npm installs.
Requirements
The hosted instance is a remote Streamable HTTP endpoint at drobek.app/mcp using OAuth 2.1, with scopes read, write and publish; no browser on the agent machine means minting an API key and sending it as an Authorization Bearer header. Self-hosting needs a linux/amd64 server with a public IP and ports 80 and 443, a dashboard domain plus an apps domain with wildcard DNS, Docker, and an SMTP account or Resend API key for sign-in codes.
Before you install
The agent can create apps, write files, publish versions and manage custom domains, so publishing makes content publicly reachable. Tokens and API keys are bound to your account and reach every workspace you belong to. App secrets are set by the owner in the dashboard and are not passed through the agent. Self-hosting requires generating and protecting secrets such as DROBEK_MASTER_KEY and POSTGRES_PASSWORD, and upgrades may need an operator step.

Installation

In SourceWeft

  1. Open Drobek in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "drobek": {
      "type": "http",
      "url": "https://drobek.app/mcp"
    }
  }
}

README

[The drobek pixel mascot]

drobek

[CI] [Release] [License: AGPL-3.0] [Image]

Open-source hosting for small web apps your own AI agent builds.

Bring Claude, Claude Code, Cursor or Codex. Your agent connects over MCP, writes the app directly into a workspace and gets compile feedback and a live preview. You decide when to publish. Platform modules supply sign-in, data, forms, e-mail, uploads and external APIs; a dashboard gives you control over the app, its users and its secrets.

Try drobek.app · Self-host · Gallery · Docs

MCP Registry name: io.github.freema/drobek. The hosted Streamable HTTP endpoint is https://drobek.app/mcp and uses OAuth 2.1.

Choose where to run it

Get started
drobek.appThe maintainer's hosted instance. Sign in and connect your agent.
Your own serverRun the same public image with Postgres, Redis and Caddy. Follow the self-host quickstart, then connect your agent to your server's /mcp endpoint.

The core is AGPL-3.0. Building, testing and self-hosting need no access to the private repository that operates drobek.app. The agent plugins are MIT and can connect to either instance.

See what people build

  • Drobek Tycoon — a playable hosting-company simulator with three levels.
  • Pokédex — PokéAPI search and stats through drobek's proxy module, with a live request log.
  • Pixel Wall — a shared 64 × 40 canvas backed by auth, data and other platform modules.
  • Pixel Crumbs — a browser pixel-art and animation editor.
  • Drobek Skok — a pixel platformer with a leaderboard.
  • Pekárna Drobek — a small bakery's demo website.

These are public apps on drobek.app. Browse the gallery for more examples.

[Drobek Tycoon running on drobek]

Build your first app

  1. Choose an instance above and connect your agent.

  2. Ask for a small app, for example:

    text
    Build a shift planner for our team on drobek.Let people sign in and see their own shifts.Give me a preview to try before publishing.
  3. Open the preview, ask for changes, then ask the agent to publish when ready.

Apps run in the browser. Their backend comes from installed platform modules; arbitrary app server code and per-app npm install are outside the execution model. For your own backend integration, write a platform module.

The loop

  1. Connect drobek to your agent (an MCP server with OAuth — you approve it in the browser).
  2. Ask for an app: "a shift planner for our warehouse". The agent calls create_app and gets a compiling starter plus a briefing of the rules.
  3. It calls write_files. drobek compiles the files in-process with esbuild and returns the compile errors in the same response; the agent fixes them and writes again. Every write is an immutable version.
  4. Each successful compile is live at once on the app's preview host, https://<slug>--preview.<APPS_DOMAIN> — the agent hands you the link.
  5. When you are happy, the agent calls publish and the version goes live on https://<slug>.<APPS_DOMAIN> (or your own domain). Publishing an older version is the rollback.

Why it is built this way:

  • The server never executes app code. It compiles and serves; the result runs only in browsers. No sandbox per app, no npm install, no server-side code of the agent's.
  • Secrets never pass through the agent. The app owner sets them in the dashboard; modules use them server-side.
  • Every app is its own origin (<slug>.<APPS_DOMAIN>), separate from the dashboard's.
  • One process, one image (ghcr.io/freema/drobek) + Postgres + Redis (+ Caddy for TLS). It runs on an ordinary small server.

Core concepts

Agent plugins and platform modules do different jobs. A plugin teaches your agent how to build on drobek. A module runs on the drobek server and adds backend capabilities for apps. Installing a plugin does not install server modules. See the repository and compatibility map.

  • Workspace — people with roles (workspace-admin / editor / viewer).

  • App — a globally unique slug, owned by a workspace. Its hosts: <slug>.<APPS_DOMAIN> (published), <slug>--preview.<APPS_DOMAIN> (the newest version that compiled), <slug>--v<N>.<APPS_DOMAIN> (exactly version N), plus verified custom domains.

  • Version — an immutable, numbered snapshot of the app's sources and compiled output. Publishing moves one pointer.

  • Platform modules — the only backend an app gets: routes under /__drobek/v1/<name> on the app's host, drobek.<name> in the browser SDK, a per-app config the agent proposes and the owner confirms when it is risky, a skill the agent reads. Built in (modules/, enabled with DROBEK_MODULES):

    • auth — the app's users sign in with an e-mailed code (allowlist, admins, <LoginGate>, sessions the owner can revoke);
    • data — collections of records with per-operation rules (public / user / owner / admin), JSON Schema, CSV;
    • forms — <Form> submissions stored and e-mailed to the owners, with bot protection;
    • email — notifications to the app's owners (never to arbitrary addresses), per-app and server-wide budgets;
    • files — end-user uploads with types sniffed from the bytes and a per-app quota;
    • proxy — calls to external APIs with the secret injected server-side, behind an SSRF guard.

    Operators can add their own modules against the public contract: npm create drobek-module@latest <name> scaffolds one against the npm packages @freema/drobek-modules + @freema/drobek-sdk (imported as @drobek/modules / @drobek/sdk through npm aliases) — docs/MODULES.md → Writing a module.

Self-host quickstart

What you need:

  • a server with a public IPv4 (and/or IPv6), linux/amd64 (there is no ARM image in v1), ports 80 and 443 reachable from the internet;

  • a domain for the dashboard and a domain for the apps. Create these DNS records before step 3 (Let's Encrypt checks them):

    RecordPoints atExample
    A (and/or AAAA) for the dashboard hostthe serverdrobek.example.com
    wildcard A/AAAA *.<APPS_DOMAIN>the server*.apps.example.net

    A separate registrable domain for the apps (example.net next to example.com) is the safer choice; apps.<your dashboard domain> works too. No DNS at all (a test box)? Use DOMAIN=localhost in step 3 — Caddy's local CA (tls internal), reachable only from the machine itself.

  • an SMTP account (host, port, user, password, a sender address) or a Resend API key — sign-in codes go out by e-mail.

Every command runs as root (or prefix sudo).

1. Docker, git and go-task

sh
curl -fsSL https://get.docker.com | shapt-get install -y git opensslsnap install task --classicdocker compose version     # → Docker Compose version v2.x (or newer)task --version             # → Task version: v3.x

2. The drobek files (the compose file, the scripts, the env template — the image itself comes from GHCR)

sh
git clone https://github.com/freema/drobek /opt/drobekcd /opt/drobekgit checkout "$(git tag -l 'v*' --sort=-v:refname | head -n 1)"   # the newest release (skip before the first one)

3. Configuration — generates every secret, writes .env.production (mode 600), renders deployments/Caddyfile with the image's own generator (no Node on the host):

sh
DOMAIN=drobek.example.com APPS_DOMAIN=apps.example.net \[email protected] [email protected] \SMTP_HOST=smtp.example.com SMTP_PORT=587 [email protected] \[email protected] \task selfhost:init

Expected output (abridged):

text
✓ created .env.production from .env.production.example (mode 600)✓ generated POSTGRES_PASSWORD✓ generated DROBEK_MASTER_KEY✓ generated TLS_ASK_TOKEN✓ dashboard https://drobek.example.com · apps https://<slug>.apps.example.net✓ TLS mode for the app hosts: on-demand✓ rendered deployments/Caddyfile (on-demand)✓ docker compose config: OK

Then put the SMTP password in (never on the command line):

sh
nano .env.production       # SMTP_PASS='…'   (single quotes if it has $, # or spaces)

task selfhost:init never asks anything and never overwrites a secret; run it again whenever you like (after changing TLS settings: then task tls:reload). The TLS default for a real domain is on-demand (one Let's Encrypt certificate per app host, gated by drobek); TLS_MODE=wildcard-file or TLS_MODE=dns pick a wildcard certificate instead — see "TLS" in docs/SELF-HOSTING.md.

4. Start

sh
docker compose --env-file .env.production -f docker-compose.production.yaml up -d --wait

The first start pulls the images and drobek applies every database migration. Expected: Container drobek-prod-postgres-1 Healthy, …-redis-1 Healthy, …-drobek-1 Healthy, …-caddy-1 Healthy.

sh
curl -s https://drobek.example.com/healthz      # → {"ok":true,"db":"up","redis":"up"}curl -s https://drobek.example.com/api/version  # → {"name":"drobek","sha":"<commit>","version":"vX.Y.Z","commitTime":"…","startedAt":"…","modules":[…]}

Tip: alias dc='docker compose --env-file .env.production -f docker-compose.production.yaml' — the rest of this guide spells the command out.

5. Sign in — open https://drobek.example.com, enter your SUPERADMIN_EMAIL, type the 6-digit code from the e-mail. You land on /me with a personal workspace.

6. Connect an agent (Claude Code)

sh
claude mcp add --transport http drobek https://drobek.example.com/mcp

Claude Code discovers drobek's OAuth server, opens the consent page in your browser (read, write, publish) and gets a token bound to you. Without a browser on the agent's machine, mint an API key on the server instead and pass it as a header:

sh
docker compose --env-file .env.production -f docker-compose.production.yaml exec drobek \  node node_modules/@drobek/oauth/dist/cli/api-key-create.js \  --email [email protected] --name laptop --scopes read,write,publish# → drk_…   (shown once)claude mcp add --transport http drobek https://drobek.example.com/mcp \  --header "Authorization: Bearer drk_…"

7. Publish an app — ask the agent: "Build a tip calculator on drobek and publish it." It calls create_app → write_files → publish; open the published_url it returns (https://tip-calculator.apps.example.net). With on-demand TLS the very first request to a new app host waits a few seconds for its certificate.

A test box without DNS — the same steps with Caddy's local CA:

sh
DOMAIN=localhost [email protected] SMTP_HOST=… task selfhost:init   # → TLS mode internaldocker compose --env-file .env.production -f docker-compose.production.yaml up -d --waitdocker compose --env-file .env.production -f docker-compose.production.yaml cp \  caddy:/data/caddy/pki/authorities/local/root.crt ./drobek-root.crtcurl --cacert drobek-root.crt https://localhost/healthz

Trust drobek-root.crt in your browser / OS to use it without warnings (Node clients: NODE_EXTRA_CA_CERTS=drobek-root.crt). App hosts are https://<slug>.apps.localhost, which browsers resolve to the machine itself. HTTPS_PORT=8443 (plus HTTP_PORT=8080) moves Caddy off 443 — every URL then carries the port.

Backups (task backup / task restore), upgrades (task selfhost:upgrade), the three TLS paths, custom domains, abuse handling and every setting: docs/SELF-HOSTING.md.

Connect your agent

The MCP endpoint is <PUBLIC_APP_URL>/mcp (OAuth 2.1; the client discovers, registers and asks for your consent by itself). Scopes: read, write, publish; the token is bound to you and reaches every workspace you belong to, with your role in each.

  • Claude Code: claude mcp add --transport http drobek https://drobek.example.com/mcp, then /mcp → sign in. For the hosted drobek: claude plugin marketplace add freema/drobek-plugin and claude plugin install drobek@drobek (MCP server + build skill + /drobek:build-app).
  • Claude (web / desktop): add a custom connector with the /mcp URL.
  • Cursor: ~/.cursor/mcp.json → { "mcpServers": { "drobek": { "url": "https://drobek.example.com/mcp" } } }.
  • Codex: for the hosted drobek codex plugin marketplace add freema/drobek-plugin, codex plugin add drobek@drobek, codex mcp login drobek.
  • Scripts / CI: a personal drk_… API key from /me/api-keys as Authorization: Bearer drk_….

The agent gets twenty-five tools — list_apps, create_app, duplicate_app, get_app, read_file, write_files, restore_version, publish, set_gallery_listing, skill_info, configure_module, query_data, get_logs, for video, audio, images and fonts create_asset_upload, list_assets, delete_asset (an upload URL — the file never passes through the model), and for custom domains list_domains, add_domain, verify_domain, set_primary_domain, remove_domain, and for the proxy module's external APIs list_upstreams, register_upstream, remove_upstream, and sync_now for the sync module's scheduled imports (a super-admin also gets set_workspace_publishing). The full agent contract (scopes, the briefing, skills, /llms.txt) is docs/AGENT.md; a running server serves it at /llms.txt, /llms-full.txt and /build-with-your-agent. To teach an agent the loop without the plugin: cp -r skills/drobek ~/.claude/skills/drobek.

Develop locally

Prereqs: Docker (compose v2) for the stack; go-task 3, Node 22 and pnpm 10 for the host-side task check / task e2e.

sh
git clone https://github.com/freema/drobek && cd drobekcp .env.example .env# Two edits make it yours (the rest have working dev defaults):#   1. SUPERADMIN_EMAIL  → the email you'll sign in with (becomes super-admin)#   2. DROBEK_MASTER_KEY → a real key:  openssl rand -hex 32task dev          # or: docker compose up -d --build
ServiceHost portCheck
drobek (dashboard + OAuth AS + MCP /mcp)3041GET /healthz → {ok,db,redis} (503 when a dependency is down); GET /health → {ok:true}
postgres 175441pg_isready
redis 76391redis-cli ping
mailpit (dev SMTP sink)8025the login codes land here

The dev stack runs every built-in module plus the example drobek-module-hello. Sign in at localhost:3041 (the code is in Mailpit), then point your agent at http://localhost:3041/mcp.

Opening apps locally. APPS_DOMAIN=apps.localhost:3041, and browsers resolve every *.localhost name to your machine — nothing to add to /etc/hosts:

HostServes
http://<slug>--preview.apps.localhost:3041the newest version that compiled
http://<slug>.apps.localhost:3041the published version ("not published yet" until the first publish)
http://<slug>--v<N>.apps.localhost:3041exactly version N

curl and Node do not resolve *.localhost everywhere; send the app host in the Host header instead:

sh
curl -i -H 'Host: <slug>--preview.apps.localhost:3041' http://127.0.0.1:3041/

Browsers refuse __Host- cookies on plain http://localhost, so the http dev stack (NODE_ENV ≠ production) uses the unprefixed, still host-only drobek_session / drobek_app_access / drobek_eu; production and every https origin use the __Host- names. task dev:tls runs the dev stack behind Caddy on https://localhost with its local CA. For scripts without an OAuth flow: task api-key:create [email protected] NAME=laptop SCOPES=read,write.

Everyday commands:

sh
task dev          # build + start the stack, wait until healthytask check        # host-side gate: install, doc-lint, build packages + app bundle, typecheck, lint, knip, unit teststask logs         # tail the drobek servicetask health       # curl the health endpointstask e2e          # Playwright suite (incl. @local specs) vs the stacktask e2e:image    # what CI runs: the prod image behind Caddy + the whole suitetask e2e:smoke    # @smoke specs only (safe against any target, prod included)task build        # build the production image ghcr.io/freema/drobek:<sha>task prod:proof   # build + prove the prod image (size, non-root, fail-closed, live boot)task dev:tls      # dev stack behind Caddy (tls internal); task dev:tls:down to leavetask db:generate  # drizzle-kit generate (journal __drizzle_migrations_core)task down         # stop the stack (docker compose down -v also wipes the data)

Contributor rules and the repository map: CLAUDE.md. Public repositories, agent plugins versus server modules, and the external consumer check: docs/ECOSYSTEM.md.

End-to-end tests

tests-e2e is one Playwright suite with two tiers:

  • @local — needs a local stack: seeds and reads Postgres / Redis / Mailpit directly. global-setup.ts TRUNCATEs the core tables first, but only with ALLOW_DESTRUCTIVE=1 AND a DATABASE_URL host on its allow-list (localhost, 127.0.0.1, postgres).

  • @smoke — public HTTP + MCP only, safe against production: never the database, Redis or Mailpit. The MCP smoke loop (mcp-loop.spec.ts) signs in with a drk_ key from SMOKE_API_KEY (read from the environment only), writes, previews and publishes a smoke-* app, and leaves nothing behind. MCP has no delete tool, so the spec cleans up by target: against the local stack (TEST_ENV=local) it creates a fresh smoke-<random> app and deletes it at the end — also when the test fails — through the dashboard delete action, signed in as the smoke user by e-mail OTP (Mailpit); against any other target (production) it re-uses ONE stable app per key, smoke-<12 hex of a SHA-256 of the key> (list_apps → get_app, then a new version + publish), so production keeps exactly one smoke app per smoke identity:

    sh
    BASE_URL_WEB=https://drobek.app SMOKE_API_KEY=drk_… task e2e:smoke

    Without the key it is skipped on a localhost target and fails anywhere else; under task e2e it mints a throwaway key in the local DB.

mcp-loop.spec.ts is the agent loop end to end: the official MCP SDK client with an OAuth provider (401 → discovery → DCR → PKCE consent driven by Playwright → token), then list_apps → create_app → write_files (compile error → fix) → preview host → publish → production host → restore_version → get_app, asserted under 90 s.

task e2e runs against the dev stack (task dev). task e2e:image is the CI flow (.github/workflows/ci.yml runs the same scripts/e2e-image.sh): build the production image, start it with docker-compose.e2e.yaml (project drobek-e2e, its own loopback ports, so it runs next to the dev stack) behind Caddy with tls internal on https://localhost:8443 and https://<slug>--preview.apps.localhost:8443, let it migrate a fresh DB, then run @smoke + @local and tear everything down. DROBEK_IMAGE=… skips the build, E2E_KEEP=1 keeps the stack, extra args go to Playwright (task e2e:image -- tests/mcp-loop.spec.ts).

Versions and upgrades

drobek follows semantic versioning; while it is at 0.x, a minor release may need an operator step, and its release notes say which. Every release is a git tag vX.Y.Z, an immutable image ghcr.io/freema/drobek:vX.Y.Z, a GitHub release and an entry in CHANGELOG.md; latest and previous move with each release (docs/SELF-HOSTING.md → Image tags). Migrations only go forward and run as their own step of task selfhost:upgrade; a rollback is the previous image plus, when the release migrated the database, the backup taken before it (Upgrades and rollback). Modules declare the contract range they need, and the server refuses to start with a module it cannot satisfy (docs/MODULES.md → Compatibility).

Extend drobek: write a module

An app's backend is a set of platform modules, and anyone can write one: an npm package against the published contract, installed by the operator without building an image.

sh
npm create drobek-module@latest erp   # routes, SDK slice, migration, SKILL.md, tests

The contract is on npm as @freema/drobek-modules; the scaffold installs it under the name module code imports, @drobek/modules ("@drobek/modules": "npm:@freema/drobek-modules@^X.Y.Z").

docs/MODULES.md → Writing a module walks through the contract, publishing and installing; examples/drobek-module-hello is a working one, and Published modules lists the modules others can install.

Contributing

Issues, questions and pull requests are welcome — see CONTRIBUTING.md. Questions and ideas go to Discussions; security issues are reported privately (SECURITY.md).

Documentation

DocumentWhat
docs/ARCHITECTURE.mdone process, origins, versions, the compiler, serving, modules, TLS, jobs
docs/SELF-HOSTING.mdthe quickstart, compose, every environment variable, TLS, backups, upgrades, custom domains, abuse
docs/MODULES.mdthe platform module contract and the built-in modules
docs/AGENT.mdconnecting agents, the tools and scopes, the briefing, skills, llms.txt
docs/SECURITY.mdthe threat model and how to report a vulnerability
docs/LICENSING.mdAGPL-3.0 §13 and the boundary with the hosted drobek.app
CHANGELOG.mdevery release

License

AGPL-3.0 — see docs/LICENSING.md.

Source: README.md at commit 4c49301

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Version history

1
  1. v0.6.0LatestSep 29, 2026