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These flags are available on every fallow command (check, dupes, fix, watch, list, init, migrate).

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Reference

FlagDescription
-r, --root <PATH>Project root directory (default: current working directory)
-c, --config <PATH>Path to config file (default: auto-detected)
-f, --format <FORMAT>Output format: human (default), json, sarif, compact
--quietSuppress progress bars and status messages
--no-cacheDisable incremental caching (force full re-parse)
--threads <N>Number of parser threads (default: number of CPU cores)
-w, --workspace <NAME>Scope output to a single workspace package
--performanceShow pipeline timing breakdown

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Examples

# Analyze a project in a different directory
fallow check -r /path/to/project

# Use a specific config file
fallow check -c configs/fallow-strict.json

# JSON output with no progress messages
fallow check -f json --quiet

# Limit parallelism to 4 threads
fallow check --threads 4

# Scope to a single workspace package
fallow check -w @myorg/ui

# Show timing breakdown
fallow check --performance

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Incremental caching

Fallow caches parsed file data between runs to skip unchanged files. On the second run, only modified files are re-parsed. The rest are loaded from cache. How it works:
  1. Each file is hashed with xxh3 (extremely fast, non-cryptographic)
  2. If the hash matches the cached version, parsing is skipped entirely
  3. The module graph is rebuilt from cached + freshly-parsed data
Use --performance to see cache hit rates and per-stage timings. This is helpful for diagnosing slow runs.
fallow check --performance

 Discovery     12ms   (142 files)
 Parsing       48ms   (23 parsed, 119 cached)
 Resolution    15ms
 Analysis       8ms
 Total         83ms
Use --no-cache to force a full re-parse. This is useful after major refactors or when debugging unexpected results. 
fallow check --no-cache
--no-cache makes every run a cold run. Only use it for debugging. Normal runs with caching are significantly faster.

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See also

Environment variables

Set defaults for format and quiet mode via environment variables.

Configuration

Full config file reference for project-level settings.