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The Mercur CLI (@mercurjs/cli@latest) manages your marketplace project — installing blocks, generating types, and checking for updates. To create a new project, use create-mercur-app.

Installation

Commands

create

Scaffolding new projects lives in the standalone create-mercur-app package, so it downloads fast and works with every package manager’s create command.
It will prompt you for database credentials and install dependencies automatically.

init

Initialize an existing project by creating a blocks.json configuration file.
This sets up path aliases so the CLI knows where to place blocks in your project:

add

Install blocks from the registry into your project.
Blocks are copied directly into your project as source code. The CLI resolves dependencies, transforms imports to match your path aliases, and installs required packages. Find available blocks in the registry.

view

Display detailed information about a block.

diff

Compare local blocks against registry versions to check for updates.
If there are changes you want, update with:

codegen

Generate TypeScript types from your API routes. Used by the API Client for type-safe requests.

registry:build

Build a custom registry from a registry.json file.

info

Display project configuration and diagnostics.

telemetry

Control anonymous usage data collection.

Custom registries

Add custom block registries to your blocks.json:
Use {name} as a placeholder for block names. Reference custom registries with the -r flag:

FAQ

create scaffolds a brand-new project from a template. init only writes a blocks.json into an existing project so the CLI knows where to place blocks — use it when adopting blocks in a repo that wasn’t created by the CLI.
After any change to API route files — added routes, changed validators, renamed paths. The typed client reads the generated route map, so stale types mean codegen hasn’t run.
Not silently — the CLI asks before overwriting existing files unless you pass --overwrite. Use diff first to see exactly what changed between your copy and the registry.

Next steps

Add a feature with a block

The install workflow end to end — search, view, add, migrate.

API Client

What codegen’s route map powers on the frontend.