CLI reference

The forst CLI transpiles .ft sources, runs programs, generates TypeScript output, and starts development services. Install via @forst/cli or a native binary.

Default compile and run

With no subcommand, forst compiles a single .ft file. Given hello.ft:

Forst
Generated Go

package main

func greet(): String {
	return "Hello, World!"
}

func main() {
	println(greet())
}

// forst build
package main

func greet() string {
	return "Hello, World!"
}

func main() {
	println(greet())
}

Run it with:

forst path/to/file.ft          # compile
forst run path/to/file.ft      # compile, build, and run
forst build path/to/file.ft    # compile and build only

Common flags (see forst --help):

Flag	Purpose
`-root <dir>`	Merge same-package `.ft` files under a directory tree
`-export-struct-fields`	Emit exported struct fields with `json` tags for `encoding/json`
`-log-level`	`trace`, `debug`, `info`, `warn`, `error`
`-watch`	Recompile on file changes

`forst generate`

Emit TypeScript declarations and client stubs from Forst sources:

forst generate ./my-service
forst generate ./handlers/orders.ft
forst generate -config ./ftconfig.json ./my-service

Uses the same file discovery rules as forst dev. Output typically lands in generated/ and client/ relative to the target.

`forst dev`

Start the HTTP development server for function discovery, invocation, and types:

forst dev -root ./my-service -port 8080
forst dev -config ./ftconfig.json -root .

See Dev server.

`forst lsp`

Start the language server (JSON-RPC over HTTP on POST /):

forst lsp -port 8081 -log-level info

Used by the VS Code extension. This is HTTP LSP rather than stdio. Other editors need a similar bridge.

`forst fmt`

Format .ft sources:

forst fmt path/to/file.ft

`forst test`

Run Forst tests (discovery and emit bridge):

forst test ./...

`forst dump`

Debug compiler phases (lexer, parser, typechecker, transformer):

forst dump --file path/to/file.ft --format pretty
forst dump --file path/to/file.ft --phase typechecker

Useful when reporting compiler bugs.

`forst clean`

Remove compiler-generated artifacts under .forst/ (run sandboxes, test emit dirs, executor temp modules, nodert sockets, invoke ready markers). User config such as .forst-gomod/ is not removed.

forst clean
forst clean -root ./my-service
forst clean -dry-run

`forst version`

Print compiler version info:

forst version
forst --version

Prints semver, commit, and build date.

npm wrapper

When installed via @forst/cli:

npx forst run hello.ft
npx forst --forst-cli-info    # package version, binary path, compiler version

Set FORST_BINARY to skip download in CI.

Quickstart

First commands in context.

Editor workflow

LSP integration in VS Code.

Overview

Getting started

Data validation

Behavior

Interop

Workflow

CLI reference

Default compile and run

`forst generate`

`forst dev`

`forst lsp`

`forst fmt`

`forst test`

`forst dump`

`forst clean`

`forst version`

npm wrapper

Quickstart

Editor workflow

​Default compile and run

​forst generate

​forst dev

​forst lsp

​forst fmt

​forst test

​forst dump

​forst clean

​forst version

​npm wrapper

​Related

Quickstart

Editor workflow

Default compile and run

`forst generate`

`forst dev`

`forst lsp`

`forst fmt`

`forst test`

`forst dump`

`forst clean`

`forst version`

npm wrapper

Related