rsync

Fast, versatile file copying and synchronization tool

workhorse C RsyncProject/rsync
72% pass rate
2/8 principles met

Spec Coverage

How many of the spec's requirements were verified for this tool. See /coverage for the full matrix.

Level Total Verified Unverified
MUST 28 19 9
SHOULD 21 13 8
MAY 10 10 0

Top Issues

All Audits

P1: Non-Interactive by Default

PASS Non-interactive by default
SKIP Non-interactive gate flag advertised in --help target satisfies P1 via alternative gate (help-on-bare or stdin-primary)
SKIP Flags advertise env-var bindings in --help target exposes no flags in --help
PASS Secret-bearing flags expose stdin or *-file companion
PASS `--help` advertises default values for flags
WARN Rich-TUI affordance for TTY contexts no rich-TUI affordance detected (no `--tui`/`--interactive`/`--ui` flag, no spinner/progress/tui mention in --help). MAY-tier — rich TUI in TTY contexts is a nice-to-have, not required.

P2: Structured, Parseable Output

OPT-OUT Structured output support no --output/--format flag detected — tool does not ship structured output. Schema-discovery requirements (p2-must-schema-print, p2-should-schema-file) collapse to n/a via antecedent propagation.
N/A Structured-output CLI exposes its schema at runtime antecedent `p2-json-output` is opt_out: no --output/--format flag detected — tool does not ship structured output. Schema-discovery requirements (p2-must-schema-print, p2-should-schema-file) collapse to n/a via antecedent propagation.
WARN --json / --jsonl short aliases for --output no --json or --jsonl short alias found. Agents and pipelines benefit from short forms alongside the canonical `--output` enum.
WARN `--raw` flag for pipe-safe unformatted output no `--raw` flag advertised. MAY-tier — useful for pipelines that want to strip formatting before piping to other tools.
SKIP `--output` advertises additional formats beyond text/json no `--output` or `--format` flag advertised; vacuous skip for MAY-tier extra formats.
WARN Bad invocation exits with structured usage-error code (2) bad invocation exited with code 1. The 0/1/2/77/78 convention reserves code 2 for usage errors; using a different non-zero code (often 1) blurs the distinction between usage errors and general failure.
SKIP Errors emit JSON envelope with `error`/`kind`/`message` under `--output json` binary does not advertise `--output json` in --help; MUST applies only to CLIs that opt into the JSON contract.
SKIP JSON success and error envelopes share their non-payload key set binary does not advertise `--output json` in --help; envelope-consistency only applies to CLIs that opt into the JSON contract.

P3: Progressive Help Discovery

PASS Help flag produces useful output
PASS Version flag works (`--version` plus short alias)
PASS Version flag works (`--version` plus short alias)
WARN `examples` subcommand or `--examples` flag for curated usage patterns no `examples` subcommand or `--examples` flag found. MAY-tier — a curated usage block keeps agents from hunting through long help text.
WARN Short `-h` summary differs from `--help` long form `-h` and `--help` produce byte-identical output. SHOULD-tier — clap renders the short summary on `-h` and the full description on `--help` when `long_about` is set; collapsing them gives agents no concise list-level grep target.
SKIP Each subcommand's `--help` ships at least one invocation example binary has no subcommands; MUST applies conditionally to CLIs that use them.
WARN Help text pairs human and `--output json` example invocations no paired text + `--output json` example found within 5 lines in top-level or any subcommand `--help`. Pairing keeps agents from reverse-engineering the JSON invocation from the text one.

P4: Fail-Fast, Actionable Errors

PASS Rejects invalid arguments
FAIL Error messages include a hint or remediation phrase stderr lacks a hint phrase. Looked for one of: try , use , expected , did you mean, see , run , for more, tip:, help:, hint:, suggestion:, available . Error messages must name what to do next, not just the symptom.
SKIP `--output json` produces JSON-formatted errors binary does not advertise `--output json` in --help; SHOULD applies only to CLIs that opt into the JSON contract.

P5: Safe Retries & Mutation Boundaries

SKIP Destructive subcommands require `--force` or `--yes` no destructive subcommands detected; MUST applies conditionally to CLIs with destructive operations.
SKIP Read and write surfaces are both visible in subcommand list no recognizable read or write subcommand verbs; the read/write distinction is unobservable from the help surface alone.

P6: Composable, Predictable Command Structure

PASS Handles SIGPIPE gracefully
WARN Pager-using CLI ships --no-pager escape hatch pager referenced in --help but no --no-pager escape hatch advertised
PASS Respects NO_COLOR
SKIP Subcommand verbs follow community-standard names no subcommands parsed from --help
WARN `--color` flag for explicit color control no `--color` flag advertised. MAY-tier — `auto|always|never` lets agents and pipelines override the TTY-based default.
SKIP Input-accepting commands read from stdin when no file is given no input-accepting subcommand detected (process/parse/convert/transform/analyze/validate/format/lint/audit); vacuous skip for the conditional SHOULD.
SKIP Subcommand naming follows a consistent verb/noun convention fewer than 2 user-defined subcommands; vacuous skip for the conditional SHOULD.
PASS Operations are subcommands, not verb-shaped flags

P7: Bounded, High-Signal Responses

PASS Quiet mode available
WARN `--verbose` flag for diagnostic escalation no `--verbose` / `-v` flag advertised. SHOULD-tier — agents debugging failures need a way to escalate diagnostic detail.
SKIP `--limit` / `--max-results` flag for list operations no list-style subcommand detected (list/ls/search/query/find/show/get); vacuous skip for the list-only SHOULD.
SKIP Cursor-based pagination flags for list traversal no list-style subcommand detected; vacuous skip for the list-only MAY.
SKIP `--timeout` flag for long-running operations no long-running subcommand detected (serve/daemon/watch/tail/monitor/follow/run/start/stream); vacuous skip for the conditional SHOULD.
WARN Help text advertises TTY-aware verbosity behavior no TTY-aware language found in `--help`. MAY-tier — automatic verbosity reduction when stdout is piped or redirected lets agents skip the explicit `--quiet` flag. Behavioral probes cannot simulate a real TTY without a pty crate, so this audit relies on documented intent.

P8: Discoverable Through Agent Skill Bundles

PASS Skill bundle has install path (`tool skill install [<host>]`)
PASS `skill install --all` for multi-runtime install
PASS `skill update` / `skill upgrade` for bundle refresh

Details

Version scored
3.4.3
Audit date
2026-06-01 17:33:57 UTC
Duration
124ms
Platform
linux/x86_64
Mode
command
Anc build
0.5.0
Install
brew install rsync

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anc audit --command rsync --output json

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