PlugWiki

base44-sandbox Skill for Claude: What It Does and How to Install It

Shows Claude how to author Base44 functions, actors, entities and agents in the cloud sandbox, where saving a file ships it.

Installs
9.1K
on skills.sh
Stars
92
on GitHub
Updated
Nov 2026
last repo commit

This is Base44's own skill for authoring code in the Base44 cloud sandbox. It lists what you can write there (backend functions, actors, entities, agents, frontend code and connectors) and the file conventions for each. Its main rule: never run deploy or push commands, because writing the file deploys it.

It relies on base44-remote-dev for the connection and tools, and on a Base44 sign-in. The folder holds only SKILL.md and bundles no scripts.

Good for

  • Base44 builders working on an app in the cloud sandbox with their own agent
  • Developers adding backend functions, realtime actors, entities or agents
  • People connecting OAuth services such as Google Calendar to a remote app

Install base44-sandbox

Claude Code

  1. 1

    Copy this prompt.

    Install the base44-sandbox skill in Claude Code. Run this command:

/plugin marketplace add base44/skills
claude plugin install base44-sandbox@base44-skills

Then check that it loaded and tell me how to use it.
  2. 2

    Paste it into Claude Code. It shows the change and asks before running it.

Pick one skill route. This skill sends you to base44-remote-dev for the connection steps, so install both, or the sandbox plugin that holds the set. The sandbox plugin installs 13 skills (counted from its plugin.json) and deliberately leaves out base44-cli. This skill's SKILL.md still links to some base44-cli reference files, which that plugin does not ship. Connect the Base44 MCP server with the second command, then /mcp, select base44 and Authenticate.

From the project README. Source.

What's in the skill

When it loads

Develop a Base44 app remotely inside Base44's cloud sandbox using your own agent — no local checkout and no deploy/push commands. The implementation is remote: writing a resource file into the sandbox is what ships it (backend functions, realtime actors, entities, and agents all auto-sync from the file you write), and OAuth connectors are set up against the remote app via MCP tools or the projectless `base44 connectors` CLI. This skill is the place for learning what you can author in the sandbox, how backend functions, actors, entities, and agents are structured, and how to connect a connector without a local filesystem. Triggers on 'develop my Base44 app remotely', 'no local files', 'cloud sandbox', 'create an entity/agent remotely', 'add realtime/multiplayer/presence remotely', 'connect a connector remotely', 'bring my own agent', or any work editing a Base44 app inside a sandbox.

Sections in SKILL.md

  1. ⚡ The mental model: writing the file is the deploy
  2. What you can author today
  3. Backend functions
  4. Actors (realtime)
  5. Entities
  6. Agents
  7. Connectors (OAuth integrations)
  8. Over MCP (base44-remote-dev transport)
  9. Over the CLI (projectless, --app-id)
  10. Using a connected connector in code
  11. Reference order & the complete README
  12. Workflow in the sandbox

Key facts

Author
Base44 (vendor's own repo)
Repo
base44/skills
License
MIT (LICENSE file; README, marketplace.json and plugin.json agree)
Installs on skills.sh
9,114 (Nov 2, 2026)
GitHub stars
92 for the whole repo (Nov 2, 2026)
Last repo commit
Nov 1, 2026
Audits on skills.sh
Gen Agent Trust Hub: pass, Socket: pass, Snyk: warn
What it includes
1 file: SKILL.md. It bundles no scripts
Part of
Plugin base44-sandbox (13 skills per its plugin.json)
Needs
base44-remote-dev for connection steps (SKILL.md)
Status
Beta, per the README

What it includes

  • Never run deploy, push, create or scaffold; a written resource file ships itself

    SKILL.md lists the commands to avoid because they assume a local project and a manual deploy step.

    Write · Writing the file is the deploy

  • Six areas: functions, actors, entities, agents, frontend code and connectors

    The first four deploy from files in the sandbox. Connectors are set up by an OAuth connect flow, not files.

    Resource table

  • Create base44/functions/<name>/entry.ts only; no function.jsonc needed

    Uses createClientFromRequest, the npm: prefix and secrets.get from base44:runtime.

    Try: “Add a backend function that processes an order”

    Write · Backend functions

  • Write base44/actors/<Name>/entry.ts, a class extending Actor

    Folder names are PascalCase with no nesting. Persist state in this.storage.

    Try: “Add a ChatRoom realtime actor”

    Write · Actors (realtime)

  • Write a .jsonc schema per entity in base44/entities; it syncs on its own

    Write · Entities

  • Write a .jsonc config per agent in base44/agents; it syncs on its own

    Write · Agents

  • List current scopes, then connect with MCP tools or `base44 connectors` commands

    The CLI route works without a local project when you pass --app-id.

    Write · Connectors

  • Check this skill, base44-remote-dev and base44-sdk before searching the web

    It can fetch the per-app onboarding README at app.base44.com/api/sandbox/<APP_ID>/local-agent/readme.md.

    Network · Reference order

  • Orient, author, verify, let it ship, checkpoint

    Verification uses npm run build, npx tsc --noEmit or npm run lint through run_command.

    Runs code · Five-step workflow

From the official docs

Permissions

High risk

What it can do

  • Read your data
  • Create and change things
  • Delete things
  • Read-only mode

Watch out for

  • Writing a file deploys it

    SKILL.md says a resource file written into the sandbox is auto-committed after about 5 seconds and goes live. There is no deploy or push step to stop at. Review each file before you let Claude write it. github.com

  • Deleting an actor file tears the actor down

    The resource table says deleting an actor's entry file tears it down. Entity and agent files auto-sync the same way. github.com

  • Connecting a connector replaces its scopes

    Connecting sets exactly the scopes passed and re-prompts for consent. List current scopes first. You open the authorization URL yourself. github.com

  • It builds on the remote-dev tools

    The sandbox tools (run_command, write_file, edit_file) come from base44-remote-dev and need its sandbox:write scope. Read that skill's safety box too. github.com

  • Actor secrets are off limits

    SKILL.md says ACTOR_TOKEN_SECRET is provisioned automatically and must not be created or overwritten, since changing it rotates the actors' keys. github.com

Technical details
Turning on read-onlyThis skill is about writing resource files. Read-only use comes from granting only the apps:read scope in base44-remote-dev.
Talks toapp.base44.com
Sign-in and keysSame as base44-remote-dev: Base44 OAuth for the MCP server, or the Base44 CLI token.
Scopes

  • Writes backend function, actor, entity and agent files into the Base44 sandbox, which deploys them

  • Runs build and type-check commands in the sandbox

  • Connects OAuth connectors for the app

Questions

What does the base44-sandbox skill do?

It tells Claude how to write Base44 app code inside the cloud sandbox: where backend functions, actors, entities and agents go, and why no deploy command is needed. Writing the file is what ships it.

How do I install base44-sandbox?

Use the install box above. It needs base44-remote-dev for the connection, so install both, or the base44-sandbox plugin, which holds 13 skills. The sandbox plugin leaves out base44-cli on purpose.

Why does it say never to run deploy?

In the sandbox there is no local project. SKILL.md says the platform deploys what you write, so commands such as deploy, push, create and scaffold do not apply. Running them would assume a local checkout.

base44-sandbox vs base44-remote-dev?

base44-remote-dev covers how to connect and use the sandbox tools. base44-sandbox covers what to author there. SKILL.md sends you to base44-remote-dev for connection steps.

Do I need base44-cli?

Not for the sandbox plugin, which leaves it out. SKILL.md does link to a few base44-cli reference files, such as functions-create.md, and tells you to ignore their deploy sections. Those links point at files the sandbox plugin does not ship.

Is it safe?

Anything written to a resource file goes live after the auto-commit, and deleting an actor file tears it down. The skill bundles no scripts. Our advice: ask Claude to show each backend function or schema before it writes it, and checkpoint at the end.

Does it work in the Claude app?

The README documents Claude Code, Codex CLI and the skills CLI for the sandbox set. The remote-dev skill describes a claude.ai chat with the Base44 MCP connector. Neither documents uploading this skill as a ZIP.

Is it an official Base44 skill?

It is in Base44's own repo, and the repo's marketplace.json describes the skills as "Official Base44 skills for Claude Code". The README marks them as beta.

Information

updated Nov 2, 2026

Repository
base44/skills
Folder
skills/base44-sandbox

base44/skillsskills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 5
  1. base44/skills README · github.com
  2. base44/skills marketplace.json · github.com
  3. base44-sandbox plugin.json · github.com
  4. base44-sandbox SKILL.md · github.com
  5. base44-remote-dev SKILL.md · github.com

Updated Nov 2, 2026.