ToolJet Marketplace Plugin Builder

Build a marketplace plugin

Turn an API source into a working plugin under marketplace/plugins/<id>/: a connection form (manifest.json), a query form (operations.json), and a QueryService (index.ts). The repo-owned validator is the gate, not this document. Built-in connectors in plugins/packages/ are out of scope; if asked for one, stop and say so.

Read marketplace/AGENTS.md first. It owns the codebase facts (layout, registry, build, OAuth widget, customTesting, @spec/ hosting); this skill links to it rather than repeating it.

To validate an existing plugin only, run step 5 and report with the checklist in references/verify.md section 6; fix nothing unless asked.

1. Intake

Ask one question at a time. Skip any the user already answered. If the user says to use defaults, state them: type api, no PRD, no icon, no design reference, current branch, version 1.0.0, V1, and a tags category (step 3).

Right after question 1, check the id is free, including built-in connector kinds:

grep -n '"id": "<id>"' server/src/assets/marketplace/plugins.json; ls marketplace/plugins/<id>
grep -l '"kind": "<id>"' plugins/packages/*/lib/manifest.json

A built-in match (e.g. googlesheets) means pick another id; the validator rejects it. A marketplace match: stop and ask whether to update that plugin instead. Updating skips step 3 and edits the existing files. Never add a second registry entry for the same id: the validator fails on duplicates (the CLI would abort with "Plugin id already exists").

2. Spec

Produce plugin-spec.json, the contract both generators work from. Route by source:

Write plugin-spec.json outside the repo (or delete it before committing). It is an intermediate artifact and is never committed. Without subagents, it may stay in the conversation instead of a file. Nothing validates it; the step 5 checks do.

User gate. Show the auth type, the operation list, operationsMode, and the schema version (V1 unless the form needs cascading V2 widgets). Proceed only on a yes.

3. Scaffold

Render the repo's plugin templates directly, with no prompts. This is what tooljet plugin create runs internally (the human path is in marketplace/AGENTS.md). Once per checkout, run npm install at the repo root first (it provides hygen; takes a few minutes).

cd marketplace
../node_modules/.bin/hygen plugin new --name <id> --type <type> --display_name "<Display Name>" --plugins_path .

It writes plugins/<id>/ (lib/{index.ts,types.ts,manifest.json,operations.json,icon.svg}, __tests__/index.js, package.json, tsconfig.json, README.md, .gitignore) and nothing else. It upper-cases the first letter of the display name (libSQL becomes LibSQL); step 4 overwrites the manifest and operations from templates. In README.md, fix the heading and replace the docs link (a placeholder page that does not exist) with a one-line description. Then:

1. Register the plugin: append an entry to server/src/assets/marketplace/plugins.json (the file has no trailing newline; keep it that way). From the repo root, fill in and run (it inserts one entry before the closing ] in the file's own format):

   node -e 'const fs=require("fs"),f="server/src/assets/marketplace/plugins.json",s=fs.readFileSync(f,"utf8").trimEnd();
   const e={name:"<Display Name>",description:"<one line>",version:"1.0.0",id:"<id>",author:"Tooljet",timestamp:new Date().toUTCString(),repo:"",tags:["<Category>"]};
   fs.writeFileSync(f,s.slice(0,-1).trimEnd()+",\n"+JSON.stringify(e,null,2).replace(/\[\s+("[^"]*")\s+\]/,"[$1]").replace(/^/gm,"  ")+"\n]")'

   tags is free-form: reuse an existing one when it fits, else one short Title Case category (Database, Weather). To list them: node -p '[...new Set(require("./server/src/assets/marketplace/plugins.json").flatMap((p) => p.tags || []))]'

2. Link the workspace: npm i in marketplace/ (updates package-lock.json).

3. If the id contains -, rename the generated class in lib/index.ts to a valid identifier.

4. Icon: save the provided SVG as lib/icon.svg, otherwise keep the placeholder.

Identity rule: marketplace/AGENTS.md (plugins.json id = source.kind = directory name).