ReScript

Create a module

fluentci init --sdk rescript
# Or add to an existing workspace:
fluentci modules add ci --sdk rescript

The SDK starter creates its own source and build configuration. The following sample belongs in src/Greeting.res. It prints a greeting, then inspects the current Git workspace; run it from a Git repository.

Pipeline example

@val @scope("Host")
external output: string => unit = "outputString"

let hello = () => {
  switch Guest.pipeline("hello")
    ->Guest.exec(["echo", "Hello from FluentCI"])
    ->Guest.exec(["git", "status", "--short"])
    ->Guest.stdout {
  | Ok(value) => output(value)
  | Error(message) => JsError.throwWithMessage(message)
  }
}

The -> operator pipes the pipeline into the first argument of the next function.

Toolchain and build

Install Node/npm and extism-js. The starter pins ReScript and the matching runtime in package.json; the compiler can be found in node_modules/.bin. Its SDK is bundled as a local .sdk/rescript dependency.

npm run build compiles ReScript, bundles the generated JavaScript with esbuild, and creates Wasm with extism-js. The -> operator passes a value as the first argument to the next function.

Results and exports

Handle both Ok and Error from terminal operations. The example writes successful output through Host.outputString and throws on failure. entry.mjs exposes hello from src/Greeting.res.mjs; the Wasm interface file must declare each exported job too.

The generated .res.mjs files are build output, not a substitute for the source and dependency lockfiles. Rebuild after SDK or compiler changes.

Run and inspect

fluentci run main hello
fluentci modules main --json

Use the configured module name instead of main if it was added as ci. CLI invocation builds the source module before running it. The resulting artifact is normally dist/plugin.wasm.

Continue with workspace modules for custom builds and artifact paths, or publishing to share the compiled plugin.