CLI reference

The feelc binary has one subcommand per task. Run feelc help for the synopsis, feelc version for the build version. Commands that take a model accept either a .rules source or a compiled .ir.bin (detected automatically) unless noted; compile, fmt and export read .rules source only, import reads .dmn.

Every command returns a non-zero exit code on failure (compile/parse error, or the per-command condition below); --json (where available) emits machine-readable output, and a structured diag.Error on a compile error (see error schema).

Authoring & evaluation

Command	Flags	Notes
`feelc run`	`--rules <f>` · `--decision <name>` · `--input '<json>'` (default `{}`) · `--json`	Evaluate one decision. Prints the value (and unit, if any).
`feelc explain`	`--rules <f>` · `--decision <name>` · `--input '<json>'` · `--json`	Justification trace: winning rule + contributing cells with source lines.
`feelc inputs`	`--rules <f>` · `--decision <name>` · `--json`	The inputs a decision transitively needs (question-flow / simulator).
`feelc compile`	`--rules <f>` · `-o <model.ir.bin>` · `--json`	Compile `.rules` → canonical IR; prints the model hash on stderr.
`feelc fmt`	`--rules <f>` · `-w` (rewrite) · `--check` (exit≠0 if unformatted)	Canonical pretty-printer. Does not preserve comments or the `model { … }` body.

Verification

Command	Flags	Notes
`feelc verify`	`--rules <f>` · `--json`	Completeness / conflicts / dead rules / subsumption, with counterexamples. Exit≠0 if any blocker.
`feelc check`	`--rules <f>` · `--claims <claims.json>` · `--json`	Semantic gate: NL claims vs engine verdicts. Exit≠0 if any claim is unsupported.
`feelc tck`	`--suite <dir>` · `--json` · `--min <pct>`	DMN TCK conformance run. Exit≠0 on any failure, or below `--min`.

Interop & docs

Command	Flags	Notes
`feelc import`	`--in <model.dmn>` · `-o <out.rules>`	DMN 1.3 XML → `.rules` (warnings on stderr).
`feelc export`	`--rules <f.rules>` · `-o <out.dmn>`	`.rules` → DMN 1.3 XML.
`feelc graph`	`--rules <f>` · `--format mermaid\|dot\|json` (default `mermaid`) · `-o <file>`	Decision-requirements graph with findings overlaid.
`feelc docs`	`--rules <f>` · `-o <DOC.md>` · `--trace` · `--spec <file>` (implies `--trace`)	Markdown reference (inputs/decisions/Mermaid graph), optional source↔rule traceability.

Service

feelc serve --rules <f.rules> [--addr :8080] [--watch] [--strict] [--ui]
feelc serve --project <dir>   [--addr :8080] [--watch] [--strict] [--ui] [--allow-edit]
feelc serve --ui              # start empty; author a model in the browser
# opt-in hardening (any mode):  [--auth-token <tok>]  [--rate-limit <rps>]
feelc healthcheck [--addr :8080]   # probe a running server's /readyz; exit 0 if ready, ≠0 otherwise
feelc mcp                          # MCP server over stdio (JSON-RPC 2.0) — see mcp.md

feelc mcp exposes the engine as Model Context Protocol tools (feelc_verify, feelc_run, feelc_explain, feelc_required, feelc_check, feelc_graph, feelc_model) over stdin/stdout, so any MCP-capable agent can author rules and let the deterministic engine decide outcomes. No flags.

--rules and --project are mutually exclusive. --watch hot-reloads on file change; --strict refuses to (re)load a model with verification blockers; --ui serves the embedded authoring UI at /; --allow-edit enables the project module-write endpoints (trusted/loopback hosts only). See the HTTP API reference for the routes. With --ui, configure your LLM in the browser or via the ANTHROPIC_API_KEY / FEELC_LLM_* environment variables (no key ⇒ AI endpoints return 501).

For exposed deployments, the server is hardened opt-in (default = open, loopback-only): --auth-token (or FEELC_AUTH_TOKEN) requires Authorization: Bearer <tok> on every route except the health probes (missing/invalid ⇒ 401); --rate-limit <rps> token-buckets requests per client IP (429 over budget). The server also shuts down gracefully on SIGINT/SIGTERM (draining in-flight requests).

feelc healthcheck performs an HTTP GET /readyz on --addr (loopback) and exits 0 when the server is ready, non-zero otherwise — it is the container HEALTHCHECK for the distroless image (which has no shell or curl): the same static binary probes itself. Orchestrators (Kubernetes, ECS) typically httpGet /healthz (liveness) and /readyz (readiness) directly and don't need it.

Environment

Variable	Effect
`FEELC_MEMLIMIT`	Process memory ceiling in bytes (default 2 GiB; `GOMEMLIMIT` takes priority).
`ANTHROPIC_API_KEY` / `FEELC_LLM_API_KEY`	Default LLM credential for `serve --ui` (overridable per request).