Frontend Workflow

The public FOL entrypoint is the fol tool, which dispatches to the versioned folc engine (see Toolchain Management).

The engine is implemented by the fol-frontend crate. It sits above:

• fol-package
• fol-resolver
• fol-typecheck
• fol-lower
• fol-backend

Its job is orchestration, not semantic analysis.

What The Frontend Owns

The frontend owns:

• CLI parsing (hand-rolled, no argument-parser dependency)
• grouped command structure
• package and workspace discovery
• project scaffolding
• package preparation and fetch/update workflows
• build, run, test, and emit orchestration
• editor command dispatch under fol tool
• shell completions
• user-facing summaries and workflow errors

Bundled std reminder:

• the current binary scaffold defaults to fol_model = "memo" and bundled std because its generated source uses hosted std.io
• a bare executable may use core or memo and does not need bundled std
• scaffolding writes the dependency automatically when its generated source needs std; users should not have to repair an incomplete scaffold manually
• running and testing host-compatible artifacts is frontend/toolchain behavior, not a bundled-std capability
• cross-target run / test remain rejected until the frontend has a runner configuration, independently of the artifact’s API tier

Compiler truth remains in the compiler crates.

Public Command Groups

The root command groups are:

• fol work
• fol pack
• fol code
• fol tool

Root aliases are single-letter only:

• fol w
• fol p
• fol c
• fol t

Run:

fol --help
fol <group> --help
fol <group> <command> --help

for the relevant usage surface.

Root Discovery

For workflow commands, the frontend discovers roots upward from the current directory or from an explicit path.

It recognizes:

• package roots via build.fol
• workspace roots via fol.work.yaml

A package root is one buildable package.

A workspace root is a parent root that owns multiple member packages and frontend-managed roots like build/cache/package-store locations.

Direct Package Use

The normal workflow shape is group-first:

fol work init --bin
fol pack fetch
fol code check
fol code build
fol code run

There is still a frontend-owned direct package path for compile-oriented use, but the grouped commands are the public workflow shape.

Output

Frontend summaries support:

• human
• plain
• json

The frontend also owns workflow-level errors such as:

• missing workspace roots
• fetch/update/store failures
• clean/completion/workflow command failures

Compiler diagnostics stay separate and flow through compiler-owned diagnostic models.