Add to an existing Better-T-Stack project

Add tooling to a Better-T-Stack project with its add flow instead of wiring it by hand. For a new project, use the scaffold-project skill.

bts.jsonc at the project root records the stack chosen at creation and a reproducibleCommand that recreates it. The add flow reads it to detect the stack and updates it afterwards.

Pick the interface

• bts_add_addons tool: the local MCP server.
• A shell: the CLI's add-json.
• Neither: give the user the command bunx create-better-t-stack@latest add --addons <names>, using the project's package runner.

The hosted MCP server can't change an existing project.

Steps

1. Read bts.jsonc. It tells you the current stack. If it's missing, add can't run. Tell the user instead of recreating the file. Never edit it by hand.

2. Check nested options. Some addons take options in addonOptions: the Fumadocs template, search and AI chat, the WXT and OpenTUI templates, the MCP addon's servers and agents, and the Skills addon's sources. Get their shape from bts_get_schema or npx create-better-t-stack@latest schema --name addonOptions.

3. Plan. Call bts_plan_addons, or run:

   npx create-better-t-stack@latest add-json --json '{
     "projectDir": "./my-app",
     "addons": ["pwa", "biome"],
     "dryRun": true
   }'

   Pass addons, a workspace package name, or both. Show the user what will change, including any conflict the plan reports.

4. Apply after the user agrees: bts_add_addons, or add-json without dryRun.

5. Prove it runs. Run <packageManager> install. With the user's OK, run the project's typecheck or build script. Report the exact error if a step fails.

6. Report what changed and the follow-up commands.

What can be added

Addons: pwa, tauri, electrobun, starlight, fumadocs, biome, oxlint, ultracite, husky, lefthook, turborepo, nx, vite-plus, mcp, skills, opentui, wxt, evlog.

• turborepo, nx and vite-plus are task runners. A project can have one.
• axiom can't be added later. It sets up deployment infrastructure, so it must be chosen at creation. If the user asks for it, say so instead of planning it.
• A workspace package (package: "shared", or add --package shared) scaffolds packages/shared with a manifest, the shared tsconfig and src/index.ts.

Rules

• Plan before every apply.
• Don't add addons the user didn't ask for.
• Never hand-edit bts.jsonc.