Skip to main content
The two most common commands you’ll reach for are sifr run and sifr build. Both compile your Sifr source to native code through the same pipeline — the difference is what happens after compilation. sifr run executes the result immediately; sifr build writes a binary to disk that you can distribute or invoke later.

​
sifr run — compile and execute

sifr run compiles your program and runs the resulting binary in a single step. When the compiler has a cached binary from a previous run on the same source, it skips the build phase and jumps straight to execution.
Pass arguments to your program after --:

​
Flags

​
Examples

sifr run prints build progress to stderr only when the binary cache misses. A cache hit produces no build output — your program’s stdout follows immediately. --quiet suppresses progress even on a cache miss.

​
sifr build — compile to a native binary

sifr build compiles your program and writes a native binary to the output directory. Use this when you want a standalone artifact you can run later, ship in a container, or benchmark.
Specify an output directory with -o:

​
Flags

​
Build output

A successful build in the default human diagnostic format writes a phase-aware summary to stderr:
With --quiet, the summary is shortened to:
Build progress and success banners appear only in the default human diagnostic format. When you use --diagnostic-format json or --diagnostic-format compact, no human-readable progress is emitted on stdout or stderr. Scripts should consume a machine-oriented format instead of parsing words like Finished or Binary.

​
Examples

The check, build, and run lock flags require package context and an authoritative Cargo.lock; Sifr rejects every constrained manifestless command instead of silently falling back to normal resolution. For Rust interop packages, the selected mode also governs signature probes and the generated Cargo build.

​
Single-file mode vs project mode

Both sifr run and sifr build select the compilation mode from the nearest ancestor sifr.toml. The mode determines how local imports are resolved. Single-file mode is used for every explicit .sifr file outside a workspace, regardless of its filename, imports, or neighboring files. Project mode is used for every valid entrypoint inside the nearest valid ancestor sifr.toml workspace, regardless of its filename or imports. A malformed discovered manifest is a hard diagnostic.
A manifest-less file compiles in isolation. Local sibling imports require a workspace manifest.
The compilation-mode resolver for sifr run, build, check, emit, and trace uses the same workspace boundary for an explicit input path.
Known issue #3128 affects the package-session preflight. If the current directory contains a source-only sifr.toml without package metadata, this preflight can fail before mode resolution. Until the issue is fixed, invoke explicit-file run, build, and check from outside that directory. Alternatively, use a complete package manifest. emit and trace do not use this preflight.