cli-for-agents

# CLI for agents Human-oriented CLIs often block agents: interactive prompts, huge upfront docs, and help text without copy-pasteable examples. Prefer patterns that work headlessly and compose in pipelines. ## Non-interactive first - Every input should be expressible as a flag or flag value. Do not require arrow keys, menus, or timed prompts. - If flags are missing, **then** fall back to interactive mode—not the other way around. **Bad:** `mycli deploy` → `? Which environment? (use arrow keys)` **Good:** `mycli deploy --env staging` ## Discoverability without dumping context - Agents discover subcommands incrementally: `mycli`, then `mycli deploy --help`. Do not print the entire manual on every run. - Let each subcommand own its documentation so unused commands stay out of context. ## `--help` that works - Every subcommand has `--help`. - Every `--help` includes **Examples** with real invocations. Examples do more than prose for pattern-matching. ```text Options: --env Target environment (staging, production) --tag Image tag (default: latest) --force Skip confirmation Examples: mycli deploy --env staging mycli deploy --env production --tag v1.2.3 mycli deploy --env staging --force ``` ## stdin, flags, and pipelines - Accept stdin where it makes sense (e.g. `cat config.json | mycli config import --stdin`). - Avoid odd positional ordering and avoid falling back to interactive prompts for missing values. - Support chaining: `mycli deploy --env staging --tag $(mycli build --output tag-only)`. ## Fail fast with actionable errors - On missing required flags: exit immediately with a clear message and a **correct example invocation**, not a hang. ```text Error: No image tag specified. mycli deploy --env staging --tag <image-tag> Available tags: mycli build list --output tags ``` ## Idempotency - Agents retry often. The same successful command run twice should be safe (no-op or explicit "already done"), not duplicate side effects. ## Destructive actions - Add `--dry-run` (or equivalent) so agents can preview plans before committing. - Offer `--yes` / `--force` to skip confirmations while keeping the safe default for humans. ## Predictable structure - Use a consistent pattern everywhere, e.g. `resource` + `verb`: if `mycli service list` exists, `mycli deploy list` and `mycli config list` should follow the same shape. ## Success output - On success, return machine-useful data: IDs, URLs, durations. Plain text is fine; avoid relying on decorative output alone. ```text deployed v1.2.3 to staging url: https://staging.myapp.com deploy_id: dep_abc123 duration: 34s ``` ## When reviewing an existing CLI - Check: non-interactive path, layered help, examples on `--help`, stdin/pipeline story, error messages with invocations, idempotency, dry-run, confirmation bypass flags, consistent command structure, structured success output.