anc.dev The agent-native CLI standard

bun

Incredibly fast JavaScript runtime, bundler, test runner, and package manager

workhorse Zig oven-sh/bun
65% 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

Audience signal: mixed

This tool sends mixed signals: some agent-readable affordances are present, others are not. Treat the warnings below as friction points, not defects.

This is an informational signal, not an authoritative verdict — see methodology. The per-audit evidence below is the ground truth.

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)
PASS Flags advertise env-var bindings 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

WARN Structured output support --output/--format flag detected but could not validate JSON via safe probes (--help/--version override output flags in most CLIs)
FAIL Structured-output CLI exposes its schema at runtime CLI emits structured output but exposes no `schema` subcommand or `--schema` flag at top level or nested one level deep. Agents need a runtime-discoverable schema to pin against shape changes.
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.
FAIL Bad invocation exits with structured usage-error code (2) binary silently accepted invalid flag (exit 0). Bad invocation must signal usage error via a non-zero exit code.
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.
PASS Short `-h` summary differs from `--help` long form
FAIL Each subcommand's `--help` ships at least one invocation example subcommands missing example invocations in their `--help`: lint. Examples teach agents the call shape faster than option tables; use clap's `after_help` or a dedicated `Examples:` block.
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

FAIL Rejects invalid arguments binary silently accepted invalid flag (exit 0)
FAIL Error messages include a hint or remediation phrase stderr was empty on bad invocation. Argument parsers must explain why the input was rejected — silent failure forces the agent to guess.
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
WARN Subcommand verbs follow community-standard names 3/6 subcommand(s) follow standard verb names. Non-standard: lint, x, repl. MAY-tier — community-standard verbs (get/list/create/update/delete) help agents predict subcommand behavior across CLIs.
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.
WARN Input-accepting commands read from stdin when no file is given input-accepting subcommand present but `--help` does not mention stdin or `-` as a path placeholder. SHOULD-tier — agents piping data into the tool expect stdin to work when no file arg is provided.
PASS Subcommand naming follows a consistent verb/noun convention
WARN Operations are subcommands, not verb-shaped flags top-level verb-shaped flag(s) found: --install. Operations belong under the `Commands:` block (`tool search "q"`), not on the flag namespace where they fight the `--help` filtering agents rely on.

P7: Bounded, High-Signal Responses

WARN Quiet mode available no --quiet/-q flag detected in --help output
PASS `--verbose` flag for diagnostic escalation
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.
WARN `--timeout` flag for long-running operations long-running subcommand present but no timeout flag advertised (looked for --timeout, --deadline, --max-time). SHOULD-tier — without a bound, agents that hit a hung operation have to enforce timeouts externally.
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
1.3.14
Audit date
2026-06-01 17:35:29 UTC
Duration
339ms
Platform
linux/x86_64
Mode
command
Anc build
0.5.0
Install
brew install bun

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Reproduce this scorecard for bun locally and inspect the failing audits:

anc audit --command bun --output json

Install anc first if you don't have it. Add --output json to get the same JSON shape committed under scorecards/.