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When you want feedback from the compiler without waiting for a full native-code build, sifr check is the right tool. It runs the parser and type-checker and reports all diagnostics, but stops before code generation or linking. When you want to see exactly what Rust code Sifr produces for a given source file, sifr emit prints it to stdout.

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sifr check — type-check without compiling

sifr check runs the compiler frontend — parsing, name resolution, and type-checking — and exits. No binary is produced and no linking happens, which makes it the fastest way to verify that your code is correct. 
sifr check main.sifr
Run a check on a whole package or workspace: 
# Check the current package
sifr check

# Check all workspace members
sifr check --workspace

# Check a specific package
sifr check --package my_lib

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Flags

FlagDescription
--workspaceCheck all Sifr-capable workspace members.
--package <SPEC> / -p <SPEC>Select one package by Cargo package spec or unambiguous package name. May be repeated.
--exclude <SPEC>Exclude a package from workspace selection.
--message-format <FORMAT>Use a Cargo-compatible message format for package checks.
--lockedRequire Cargo.lock to be unchanged.
--offlineDisable network access.
--frozenCombine --locked and --offline.

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Using check in your workflow

sifr check is designed for tight edit-check loops. Run it on save, in a watch loop, or as the first step in CI before invoking sifr build. 
# Check a single file
sifr check main.sifr

# Check and emit compact diagnostics for CI
sifr --diagnostic-format compact check main.sifr

# Check and emit JSON for a tool or editor
sifr --diagnostic-format json check main.sifr

# Check the whole workspace with compact output
sifr --diagnostic-format compact check --workspace
Use sifr check as your primary feedback loop during development and reserve sifr build for when you need an artifact. Check is substantially faster because it skips code generation and linking.

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sifr emit — inspect the generated Rust code

sifr emit runs the compiler up through code generation and prints the generated Rust source to stdout. No binary is written. This is useful when you want to understand how Sifr translates a particular construct, diagnose unexpected output, or satisfy your curiosity. 
sifr emit main.sifr
Pipe the output to a pager or capture it to a file: 
sifr emit main.sifr | less
sifr emit main.sifr > generated.rs

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Example

Given this Sifr source: 
# hello.sifr
def main():
    name: str = "world"
    print(f"Hello, {name}!")
Running sifr emit hello.sifr prints the corresponding Rust code that the compiler produced before handing off to the Rust toolchain.
The output of sifr emit reflects the compiler’s internal representation and is not intended to be a stable public API. Its exact form may change between compiler versions as the code generator evolves.

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Diagnostic output formats

Both sifr check and sifr emit respect the global --diagnostic-format flag. Pass it before the subcommand name.
Source snippets, caret highlights, notes, help text, and documentation URLs. Best for interactive use.
sifr check main.sifr

error[SIFR-TYPE-0042]: expected `int`, found `str`
  --> main.sifr:4:18
   |
 4 |     count: int = "three"
   |                  ^^^^^^^ type mismatch
   |
   = help: assign an integer value, for example `3`

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Explaining a diagnostic code

When you see a diagnostic code such as SIFR-TYPE-0042, pass it to --explain to get a human-readable description without re-running the compiler: 
sifr --explain SIFR-TYPE-0042
Request JSON output for programmatic consumption: 
sifr --diagnostic-format json --explain SIFR-TYPE-0042
--explain works for any diagnostic code the compiler knows about and exits with code 0 on success or 2 if the code is unknown.