Generators

CLI Generator Plan

CLI Generator Plan

Default behavior: generating <server>.ts in the working directory if no output path is provided. Bundling is opt-in via --bundle and produces a single JS file with shebang; otherwise we emit TypeScript targeting Node.js. Rolldown handles bundling by default unless the runtime resolves to Bun—in that case Bun’s native bundler is selected automatically (still requires --runtime bun or Bun auto-detection); --bundler lets you override either choice.

#Goal

Create an mcporter generate-cli command that produces a standalone CLI for a single MCP server. The generated CLI should feel like a Unix tool: subcommands map to MCP tools, arguments translate to schema fields, and output can be piped/redirected easily.

#High-Level Requirements

  • Input: Identify the target server either by shorthand name or by providing an explicit MCP server definition.
  • Output: Emit a TypeScript file (ESM) targeting Node.js by default (<server>.ts unless --output overrides). Bundling to a standalone JS file happens only when --bundle is passed.
  • Runtime Selection: Prefer Bun when it is available (bun --version succeeds); otherwise fall back to Node.js. Callers can force either runtime via --runtime bun|node.
  • Schema-Aware CLI: Leverage createServerProxy to map positional/flag arguments to MCP tool schemas, including defaults and required validation.
  • Unix-Friendly Output: Provide --output text|json|markdown|raw flags so results can be piped; default to human-readable text. Include --timeout (default 30s) to cap call duration.
  • Shell Completion (optional): Generate completion scripts for bash/zsh/fish if requested.
  • Documentation: Update README (or similar) to show how to generate and use the CLI.

#Steps

  1. Command Scaffolding
  • Add generate-cli subcommand to the existing CLI.
  • Parse flags: --server, --name, --command, optional --description, plus --output, --runtime=node|bun, --bundle, --bundler=rolldown|bun, --minify, --compile, --include-tools, --exclude-tools, etc. Runtime auto-detects Bun when available, and the bundler inherits that choice unless overridden.
  • Optional --include-tools / --exclude-tools flags allow generating a CLI that exposes only a subset of tools (mutually exclusive).
  1. Server Resolution
  • If --server matches a configured name (via loadServerDefinitions), use that server definition.
  • Otherwise, if the value looks like a file path, load a Cursor-style JSON definition from disk.
  • Otherwise, attempt to parse inline JSON/JSON5.
  • When --command (or the first positional argument) looks like a shell command (contains whitespace), split it into command + args and treat it as stdio. Otherwise, normalize HTTP selectors (https://, http://, or host/path.tool) so generate-cli mcp.context7.com/mcp autoconfigures an HTTP transport.
  • Validate that a definition is found; prompt on failure.
  1. Tool Introspection
  • Use listTools(server, { includeSchema: true }) to inspect MCP tool schemas.
  • For each tool, extract required/optional arguments, types, and defaults.
  1. Template Generation
  • Build a template (probably EJS or string interpolation) that:
  • Imports createRuntime and createServerProxy.
  • Creates a CLI (likely using commander or a minimal custom parser) with subcommands per tool.
  • Bakes in server metadata (command/url, headers, etc.) or references config path if preferred.
  • Adds output-format handling.
  • Include package.json scaffolding if --bundle or --package is set.
  1. Optional Bundling
  • If requested, run Rolldown (default when targeting Node) or Bun’s bundler (default when the runtime is Bun, or when --bundler bun is passed) to emit a single JS file with shebang (Node or Bun), with optional minification.
  • When targeting Bun, allow --compile to delegate to bun build --compile and generate a self-contained binary. Bun bundling requires staging the template inside the package tree so dependencies resolve even when invoked from empty directories.
  • Otherwise, leave as TypeScript/ESM and document how to run (node path/to/cli.js or bun path/to/cli.ts).
  1. Testing
  • Add generator unit tests (snapshot the emitted CLI for known schemas).
  • Add integration tests that run the generated script against a mock MCP server.
  1. Docs/Examples
  • Document usage in README.
  • Provide an example generated CLI under examples/generated/<server>.ts (if we keep an examples directory).

#Notes

  • Generated CLI depends on the latest commander for argument parsing.
  • Default timeout for tool calls is 30 seconds, overridable via --timeout.
  • Runtime flag remains (--runtime bun) to tailor shebang/usage instructions, but Node.js is the default.
  • Generated CLI embeds the resolved server definition and always targets that snapshot (no external --config or --server overrides at runtime).

#Usage Examples

# Minimal: infer the name from the command URL and emit TypeScript (optionally bundle)
npx mcporter generate-cli \
  --command https://mcp.context7.com/mcp \
  --minify

# Provide explicit name/description and compile a Bun binary (falls back to Node if Bun missing)
npx mcporter generate-cli \
  --name context7 \
  --command https://mcp.context7.com/mcp \
  --description "Context7 docs MCP" \
  --runtime bun \
  --compile

chmod +x context7
./context7
  # show the embedded help + tool list

# Shareable "one weird trick" for chrome-devtools (no config required)
npx mcporter generate-cli --command "npx -y chrome-devtools-mcp@latest"

- `--minify` shrinks the bundled output via the selected bundler (output defaults to `<server>.js`).
- `--compile [path]` implies bundling and invokes `bun build --compile` to create the native executable (Bun only). When you omit the path, the compiled binary inherits the server name.
- Use `--server '{...}'` when you need advanced configuration (headers, env vars, stdio commands, OAuth metadata).
- Omit `--name` to let mcporter infer it from the command URL (for example, `https://mcp.context7.com/mcp` becomes `context7`).
- When targeting an existing config entry, you can skip `--server` and pass the name as a positional argument:
  `npx mcporter generate-cli linear --bundle dist/linear.js`.
- When the MCP server is a stdio command, you can also skip `--command` by quoting the inline command as the first positional argument (e.g., `npx mcporter generate-cli "npx -y chrome-devtools-mcp@latest"`).
- Generated CLIs preserve `lifecycle: "keep-alive"` for embedded stdio servers. At runtime they create a stable generated config under `~/.mcporter/generated/` (or `$XDG_STATE_HOME/mcporter/generated/` when set), auto-start the daemon as needed, and keep the server process alive across separate generated-CLI invocations.
- Narrow the CLI to a specific subset of tools with `--include-tools`:
  `npx mcporter generate-cli linear --include-tools issues_list,issues_create`.
- Hide debug or admin tools with `--exclude-tools`:
  `npx mcporter generate-cli linear --exclude-tools debug_tool,admin_reset`.

#Artifact Metadata & Regeneration

  • Every generated artifact embeds its metadata (generator version, resolved server definition, invocation flags). A hidden __mcporter_inspect subcommand prints the payload without contacting the MCP server, so binaries remain self-describing even after being copied to another machine.
  • mcporter inspect-cli <artifact> shells out to that embedded command and prints a human summary (pass --json for raw output). The summary includes a ready-to-run generate-cli command you can reuse directly.
  • mcporter generate-cli --from <artifact> replays the stored invocation against the latest mcporter build. --server, --runtime, --timeout, --minify/--no-minify, --bundle, --compile, --output, and --dry-run let you override specific pieces of the stored metadata when necessary.
  • Because the metadata lives inside the artifact, any template, bundle, or compiled binary can be refreshed after a generator upgrade without juggling sidecar files.

#Status

  • generate-cli subcommand implemented with schema-aware proxy generation.
  • ✅ Inline JSON / file / shorthand server resolution wired up.
  • ✅ Bundling via Rolldown by default (or Bun automatically when the runtime is Bun, with --bundler available for overrides) plus optional minification and Bun bytecode compilation.
  • ✅ Integration tests cover bundling, minification, compiled binaries, and metadata/regeneration flows against the mock MCP server.

Next steps:

  1. Add optional shell completion scaffolding if demand arises.
  2. Explore templated TypeScript definitions for generated CLIs to improve editor tooling.