CLI Reference
The CLI is the most direct way to use kUML — render, watch, generate, validate, simulate,
import, export, reverse-engineer, and run models. Every subcommand prints its own help with
--help; kuml --help lists them all.
Synopsis
kuml <subcommand> [options] <input>
Options available on every command:
-
--version— print version and exit (on the barekumlcommand) -
--help/-h— print the help of the command or subcommand
Most commands take a single *.kuml.kts script as input. To process several scripts, call the command
once per file (for example from a shell loop or from the Gradle plugin).
kuml render
Render a script to SVG, PNG, LaTeX/TikZ or an animation.
kuml render [options] <script>
Options:
-
-o,--output <path>— output file -
-f,--format svg|png|latex|tex|apng|webp|mp4— defaultsvg.latex/texemit TikZ output (UML, SysML 2, C4, and BPMN are all supported).apng,webpandmp4export an animation (see--animated);webpandmp4needimg2webporffmpegon thePATH. -
--theme <name>— theme name (kuml,plain,elegant,playful); the default iskuml. Overrideskuml.config.kts. -
--layout auto|elk|grid— layout engine override.auto(the default) uses ELK for every diagram type;gridopts in to the experimentalkuml.gridengine. -
-w,--width <pixels>— PNG width (height is derived from the aspect ratio) -
--config <path>— load akuml.config.ktsfile -
--animated— emit an animated SMIL SVG (state machines and activities; see SMIL Animation).--trace <path>supplies akuml.trace.v1file for trace-driven animation (without it a demo sequence is synthesised);--speed <factor>sets the playback speed. -
--latex-standalone— emit a complete compilable LaTeX document instead of a baretikzpicturesnippet (only with--format latex). -
--notation martin|bachman|chen|idef1x— ERM notation override (ERM diagrams only). -
--watermark— opt-in visible "Powered by kUML" label in the bottom-right corner; the canvas grows downward so it structurally cannot overlap diagram content (added in v0.38.0). Independent of the always-on<!-- Generated by kUML vX.Y — kuml.dev -→metadata comment, which is emitted on every render regardless of this flag.
If the script contains a umlModel { … } with multiple diagrams, each diagram renders
to its own file using the diagram name as the file stem.
kuml render auto-detects the modelling language from the script’s return value — UML,
SysML 2, C4, or BPMN (bpmnModel { … }). For BPMN models it also runs the
BPMN constraint checker and prints any
violations as warnings before writing the output.
kuml generate
Generate code from a script using a registered code generator.
kuml generate --input <script> [options]
Options:
-
-i, --input <script>— path to the*.kuml.ktsscript (classic mode). Repeat the option to merge several UML class scripts into one model first (same rules askuml transform); the generator then runs once on the merged model. Several ERM scripts are not supported. -
-o, --output <dir>— output directory (created if missing) -
--plugin <name>— generator name (kotlin,java,sql,exposed, or custom) -
--package <fqn>— target package (Java/Kotlin) -
--options key=value,key=value— generator-specific options
Examples:
kuml generate --input model.kuml.kts --plugin java --package com.example --options java-style=records --output gen/
kuml generate --input model.kuml.kts --plugin sql --options sql-dialect=mysql,sql-drop=true --output gen/
--sql-migration: additive-only schema-diff migrations
A second mode diffs two ERM model snapshots and writes a single additive-only Flyway
migration file — mutually exclusive with -i/--input:
kuml generate --sql-migration \
--from schema-v1.kuml.kts \
--to schema-v2.kuml.kts \
--version 2 \
--description add_orders \
--output migrations/
Writes migrations/V2__add_orders.sql. Both scripts must be ERM models; any destructive
or ambiguous change (dropped/renamed entity or column, type or primary-key change) makes
generation refuse with the full list of blockers. See
ERM DSL for details.
kuml validate
Validate expressions and structure. Exits non-zero on any violation.
kuml validate [options] <script>
Options:
-
-o,--output,--format text|json— output format (default: human-readabletext) -
--strict— also fail on any expression parse warning (guards, effects, parametric constraints) -
--check-stereotypes— additionally validate stereotype applications (required properties, OCL constraints from profiles); off by default -
--no-check-structure— skip structural checks (duplicate IDs, circular inheritance, dangling references) -
--no-check-style— skip the named-argument source-style check
Output is structured: every violation prints constraint name, host classifier, OCL body, and a short failure message. Exit code 5 on violations, 0 on clean. Suitable as a CI step.
See Validation Reference for full flag details, exit codes, and a GitHub Actions integration example.
kuml diagnostics
Emit script compile/eval diagnostics with their source locations, for editor and IDE integration (this is what the JetBrains plugin’s inline error highlighting uses).
kuml diagnostics <script>
Unlike kuml validate — which focuses on OCL/structural model violations and prints
script errors as a plain, location-less message — diagnostics preserves the line and
column of every diagnostic so an editor can place squiggles precisely.
Output is one diagnostic per line on stdout, tab-separated (so consumers need no JSON parser):
<severity> <startLine> <startCol> <endLine> <endCol> <message>
-
severityisWARNING,ERROR, orFATAL(only these are reported). -
Location fields are empty when the diagnostic carries no location (e.g. a whole-file failure). The
messageis the last field, with any tab/newline replaced by a space, sosplit('\t')with a limit of 6 is always safe. -
The command always exits 0 — validity is conveyed by the emitted lines, not the exit code, so callers can parse the result regardless of script validity.
Example — a script with two unresolved references:
$ kuml diagnostics broken.kuml.kts
ERROR 3 5 3 13 Unresolved reference 'nonsense'.
ERROR 3 18 3 19 Unresolved reference 'y'.
A valid script produces no output.
kuml simulate
Run a state-machine, activity or BPMN process simulation. See the simulate reference for the full event/trace format.
kuml simulate [options] <script> [<events>]
<events> is the JSON file with the event array; omit it with --interactive.
Options:
-
--interactive— REPL mode (no events file) -
--out <path>— write the trace to a file (otherwise stdout) -
--expected <path>— diff trace against an expected file; exit code 7 on mismatch -
--epoch-clock— replace wall-clock timestamps with monotonic epoch ms from 0 -
--max-steps <n>— step limit for activity execution (default 1000) -
--sandbox— run guards and effects in the sandbox;--guard-timeout-ms <n>sets the guard timeout (default 100) -
--process <id>— BPMN process to execute when the model declares several -
--max-tokens <n>,--time-budget-ms <n>— token-flow limits for BPMN and activity models (defaults 10000 and 30000) -
--strict-guard-coverage— treat an exclusive/inclusive split with no matching guard and no default edge as an error
kuml transform
Model-to-model (M2M) and model-to-text transformation. Applies a named transformer to a kUML source script and writes the result into an output directory.
kuml transform [options] <script>...
Options:
-
-t,--transformer <id>— transformer ID (required unless--list-transformersis given) -
--list-transformers— list all registered transformers and exit -
-o,--output <dir>— output directory for the generated files -
--from bpmn|uml-activity,--to uml-activity|bpmn— shorthand for the two BPMN bridge transformers -
--package <name>— override the output package name (transformer-specific) -
--options key=value,key=value— transformer context options, for exampleidType=uuid.--packageis shorthand forpackage=; giving both with different values is a usage error. -
--model-name <name>— name of the merged model (several scripts only, defaultmerged) -
--trace-out <file>— write the transform trace as JSON
Built-in transformers: uml-to-jpa, uml-to-rest (OpenAPI 3.0), uml-to-k8s, uml-to-docker,
uml-to-erm, uml-to-erm-script, uml-to-exposed, uml-to-exposed-psm, uml-to-exposed-via-erm,
erm-to-exposed, c4-to-uml, bpmn-to-uml-activity, uml-activity-to-bpmn, arxml-to-sysml2 and
sysml2-to-arxml. Plugins can register more; --list-transformers prints the current set with
descriptions.
Examples:
kuml transform --list-transformers domain.kuml.kts
kuml transform domain.kuml.kts --transformer uml-to-rest --output api/
kuml transform process.kuml.kts --from bpmn --to uml-activity --output out/
See SysML 2 DSL Reference for the SysML 2 transformer targets.
Multi-script models
Large models are often split across several scripts. A script that needs an entity owned by another script declares a minimal stub of it (at least the id) so that associations can point at it. Passing several scripts merges their UML class diagrams into one model, removes those stubs, and runs the transformer once:
kuml transform 00-members.kuml.kts 10-orders.kuml.kts 20-tags.kuml.kts \
--transformer uml-to-exposed-via-erm --options idType=uuid --package com.example.db --output gen/
Merge rules:
-
Scripts are processed in sorted order of their canonical path, so the result does not depend on the order of the arguments.
-
Classes with an
«Entity»stereotype and a non-blanktableNametag are grouped by that tag. The declaration with the most attributes is canonical; on a tie the first one in sorted script order wins. -
Every other declaration of the group must only have attributes the canonical one also has. Otherwise the merge fails with exit code 18, naming the table, both classes, both scripts and the offending attributes. Nothing is written.
-
Classes without that tag and interfaces are de-duplicated by name (per kind) across scripts with the same rule: the declaration with the most members (attributes plus operations) is canonical, and every declaration from another script may only have members the canonical one has, otherwise exit code 18. Same-named declarations inside one script are left alone. This also applies to
kuml generatewith several-iscripts, so that a stub never overwrites the full declaration in the generated file. -
Enumerations are de-duplicated by name: the declaration with the most literals is canonical, and every other declaration may only have literals the canonical one has. Otherwise the merge fails with exit code 18.
-
References to removed stubs (association ends, generalizations, realizations, dependencies) are redirected to the canonical class. Associations that become identical afterwards (same unordered pairs of
(type, role)ends) are kept once. If such duplicates from different scripts differ in name, applied stereotypes (for example a foreign key withonDelete), multiplicity, navigability or aggregation, the merge fails with exit code 18 instead of silently picking one. -
Output order: the elements of all scripts in sorted order (the canonical declaration keeps its own position), followed by all associations. The merged model is therefore equivalent to a single script that contains the same elements in this order without the stubs, and generates byte-identical output.
Multi-script mode accepts UML class diagrams only. A BPMN transformer, --from/--to, a C4 or ERM script, a
repeated file or more than 1000 scripts is rejected. The transformer must consume UML class diagrams (for example
uml-to-exposed-via-erm or uml-to-jpa); one that needs another input type, such as erm-to-exposed, is rejected
with a usage error. With a single script the behaviour is unchanged.
kuml version
Print kUML version information.
kuml version [--json]
Options:
-
--json— emit version info as a single-line JSON object ({"version":"…","gitSha":"…","jdk":"…","buildTime":"…"})
Without flags, prints the same human-readable version string as kuml --version.
Useful in CI to record the exact kUML version used for a build artefact.
kuml export
Export a kUML model to an external format.
kuml export --format structurizr|xmi|arxml|profile-uml [--output <path>] <script>
Options:
-
--format <name>—structurizr(Structurizr DSL),xmi(Eclipse EMF/UML2 XMI),arxml(AUTOSAR ARXML) orprofile-uml(aKumlProfileas an Eclipse UML2.profile.uml) -
--output <path>— output file (default: the input name with the format’s extension)
xmi needs the JVM distribution (EMF is not part of a native-image build); a build without it
exits with code 24. See EMF / XMI I/O,
AUTOSAR / ARXML I/O and Structurizr export.
kuml import
Read an external format back into a *.kuml.kts script.
kuml import --format structurizr|xmi|arxml [--output <path>] <input>
Options:
-
--format <name>—structurizr(workspace.dsl),xmi(.xmi) orarxml(.arxml) -
--output <path>— output*.kuml.ktsfile (default: the input name with a.kuml.ktsextension)
kuml profile
Inspect registered profiles. Useful for debugging stereotype-driven codegen.
kuml profile list
kuml profile show JavaEE
kuml profile validate JavaEE # self-check: every stereotype constraint is parseable
kuml reverse
Reverse-engineer Java or Kotlin source code, SQL DDL, or ARXML files into a *.kuml.kts script.
Discovers reverse engines via ServiceLoader from
kuml-codegen-reverse-java (V3.0.7) and kuml-codegen-reverse-kotlin (V3.0.8).
kuml reverse --list-engines # list registered engines
kuml reverse src/main/java --lang java --output domain.kuml.kts
kuml reverse src/main/kotlin --lang kotlin --output domain.kuml.kts
kuml reverse src/main/java --lang auto # majority-vote on file extensions
kuml reverse src/main/kotlin --verbose-diagnostics # print every INFO/WARN on stderr
Options:
-
--lang java|kotlin|auto— source language. Default:auto(file-extension majority, ≥ 60 % share required). -
--output <file>— write the generated*.kuml.ktshere; defaults to stdout. -
--include "<glob>"(repeatable) — file include patterns. Defaults:**/*.java/**/*.ktper--lang. A glob matches if it matches the file name or the path relative to the source root (always compared with/separators;**/also matches files directly in the root). Supported syntax:,*,?,[abc],{a,b}. Matching is case-sensitive; a backslash is treated as a path separator, not as an escape. -
--exclude "<glob>"(repeatable) — file exclude patterns, same matching as--include. Excludes always win over includes. Examples:--exclude "*Test.kt"(by file name),--exclude "**/test/**"(by path). Excluded files are not parsed and do not appear in the model; references to their types stay as plain type names. -
--model-name <name>— name of the generated model (defaultReverseEngineered). -
--format source|arxml|sql— what to reverse: source code (default), ARXML import and merge, or SQL DDL to an ERM model. -
--dialect <name>— SQL dialect for--format sql(defaultpostgres). -
--list-engines— print available reverse engines (id + description) and exit. -
--verbose-diagnostics— print every WARN/INFO diagnostic on stderr (default: one-line summary).
--include/--exclude are currently applied by the Kotlin engine only. The Java engine still
compares globs with the file name only (path globs such as **/test/** have no effect there). With
--lang kotlin an include of exactly **/*.java (the Java default) is ignored.
|
The Kotlin engine is JVM-only (it bundles kotlin-compiler-embeddable), so the
reverse subcommand is available in the Fat-JAR / installDist / distTar /
runtimeZip distributions but excluded from the GraalVM Native Image build.
Diagnostic codes are grouped per engine:
-
REV-CORE-NNN— engine-agnostic -
REV-J-NNN— Java engine -
REV-K-NNN— Kotlin engine
See the kuml-codegen-reverse-api README for the full table.
kuml ai
Inspect and manage AI provider configuration, agent tool sets, benchmarks, pricing, compliance audit logs, and the API key vault:
kuml ai provider list # configured LLM providers
kuml ai tools list # agent tool sets (including the MCP bridge)
kuml ai bench # benchmark provider latency/quality
kuml ai pricing # provider pricing tables
kuml ai audit # compliance audit log
kuml ai vault # API key vault (AES-256-GCM)
kuml ai is not the MCP server entry point — there is no mcp-stdio subcommand. The
MCP server is the standalone kuml-mcp binary (module kuml-mcp, mainClass =
dev.kuml.mcp.MainKt), started directly as /path/to/kuml-mcp/bin/kuml-mcp. It exposes
6 authoring tools (kuml.render/validate/list_elements/describe/generate/examples) and
5 Behaviour-Runtime tools (kuml.run.start/event/snapshot/patch/stop) — agents
can query and drive a kUML model the same way they query a database. See
Authoring MCP and
Behaviour-Runtime MCP for the full tool reference.
kuml workspace
Inspect, validate and render OKF knowledge workspaces — directory trees of Markdown
documents with type: frontmatter and ` ```kuml ` diagram blocks:
kuml workspace init [--name <name>] [--mode knowledge|engineering] [--output <dir>]
kuml workspace info <dir>
kuml workspace validate <dir> [--strict-vocabulary] [--document <path>]... [--evaluate] [--strict]
kuml workspace render <dir> [-f svg|png] [-o <dir>] [--document <path>]... [--strict] [--no-mirror]
kuml workspace convert <src> --to okf|kts [--force] [--output <dir>] [--strict]
kuml workspace export <dir> --format pdf [--kind handbook|per-document|diagrams] [-o <file-or-dir>] [--force] [--strict]
export writes the workspace as PDF (handbook, one PDF per document, or a diagram folio) and runs the
workspace’s diagram scripts; see Workspace PDF export.
init scaffolds a new workspace into --output (default ./<slug> from --name); info,
validate and render take the workspace root as a positional <dir>; convert (added in
v0.38.0) takes a single .kuml.kts script or OKF Markdown note (or a directory of them) and
wraps/unwraps it into the other format — a text-level operation, not a model
re-serialization, since both formats share identical DSL text.
This is the canonical subcommand group for workspace-level operations — there are no
top-level kuml validate/kuml render aliases for it. See
Knowledge Workspaces for the .kuml-workspace.toml
marker format, the full type: vocabulary, and the OKF-* finding codes, including the
OKF-C-00x codes specific to convert.
kuml watch
Re-render a script every time it changes. Never exits on a script error (it prints the error and
waits for the next save); stop it with Ctrl+C.
kuml watch [--output <path>] [--format svg|png] [--width <px>] <script>
kuml fmt
Format *.kuml.kts files in place.
kuml fmt [--check] [--canonical] <script>...
-
--check— do not modify anything; exit6if any file needs formatting (for CI). -
--canonical— apply the canonical normal form used for deterministic model hashing (removes all blank lines and unifies line endings). Stricter than the default format; combine with--checkto verify hash stability in CI.
kuml serve
Start the browser editor: a Ktor/Netty server with a CodeMirror 6 editor, a live SVG preview, theme and layout selection, and SVG / PNG / LaTeX download.
kuml serve [--port <n>] [--host <address>]
The frontend is bundled with the distribution and loads no script from a third-party CDN.
kuml markdown and kuml asciidoc
Pre-render ` ``kuml ` blocks (Markdown) or `[source,kuml] blocks and kuml::path[] macros
(AsciiDoc) to diagrams.
kuml markdown -i <in.md> -o <out.md> [--mode inline|linked-svg|linked-png] [--assets-dir <dir>] [-w <px>]
kuml asciidoc -i <in.adoc> -o <out.adoc> [--mode ...] [--assets-dir <dir>] [-w <px>] [--with-source]
kuml asciidoc --input-dir <dir> --output-dir <dir> [--quiet]
--mode selects how diagrams are embedded: inline (SVG in the document), linked-svg or
linked-png (files written to --assets-dir, default <output-dir>/assets). The directory form
of kuml asciidoc mirrors a whole Antora module tree and copies other files unchanged; it is the
pre-render step Antora needs, because Antora’s Node.js Asciidoctor cannot load the JVM extension.
See Markdown and AsciiDoc & Antora.
kuml run
Run a state machine or activity with a live event adapter.
kuml run [--adapter stdin|mcp|batch|chain-evm] [options] <script>
| Adapter | Behaviour |
|---|---|
|
Interactive REPL; built-in |
|
Local REST server ( |
|
Replays |
|
Streams events from an EVM contract ( |
Persistent sessions: --restore <snapshot.json> resumes from a snapshot, --snapshot-out <path>
writes one when the session ends, and --migration reject|fingerprint|vertices chooses the
compatibility policy (default fingerprint). Supports UML, SysML 2 STM and ACT.
kuml trace
Inspect, replay and export behaviour traces.
kuml trace replay [-v] [--events <file>] [--max-steps <n>] <tracefile> <script>
kuml trace export [--format otlp-json] [--service-name <name>] [-o <path>] <tracefile>
replay re-executes a recorded state-machine or activity trace against its source model and
compares the result (exit 8 on a mismatch). export converts a trace to OpenTelemetry OTLP
JSON.
kuml sandbox
kuml sandbox validate [--strict] [--guard-timeout-ms <n>] <script>
Statically checks guards and action bodies against the sandbox policy (exit 12 on violations).
--strict uses the strict preset (short timeout, no built-ins, minimal limits).
kuml chain
Connect behaviour-runtime models to EVM contracts.
kuml chain connect --rpc <url> --contract <0x…> # print the on-chain model identity
kuml chain verify --rpc <url> --contract <0x…> <model> # local canonical hash vs. on-chain modelHash (exit 50 on mismatch)
kuml chain events --rpc <url> --contract <0x…> [--from-block <n>] [--limit <n>]
kuml chain sign --private-key "$KUML_SIGNING_KEY" [--out <file>] <model> # EIP-712 signature (secp256k1)
kuml chain verify-sig [--sig <file>] [--expected-signer <address>] <model>
Pass the signing key through an environment variable as shown, so it never lands in your shell history.
See Chain Adapters for the full guide.
kuml plugin
Install and manage kUML plugins (Theme, Renderer, Layout, Codegen, Reverse).
kuml plugin list # installed plugins
kuml plugin search [query] [--category <c>] [--sort rating|downloads|name]
kuml plugin install [--force] <plugin.jar>
kuml plugin remove <id>
kuml plugin info <id>
kuml plugin permissions <id> # declared permissions
kuml plugin check-updates # exit 44 if updates are available
kuml plugin upgrade [--all] [-y] [<id>] # exit 45 if --all and one upgrade failed
kuml plugin reload # re-read plugins from disk (development)
kuml plugin init [<category>] [--id <id>] [--name <name>] [--output <dir>]
install verifies the plugin’s Ed25519 signature; --skip-signature-check exists only for local
development JARs. Plugins that touch the file system must declare permissions, which install and
upgrade ask you to confirm (-y accepts them). init scaffolds a starter project for one of the
five categories (theme, renderer, layout, codegen, reverse); the template repository is
kuml-dev/plugin-template. The registry is plugins.kuml.dev.
kuml update
Check GitHub for a newer release (kUML never updates itself).
kuml update check # exit 0 = current, 10 = update available, 11 = pre-release only, 1 = offline
kuml update notes [--target <tag>] [--offline] [--no-cache]
kuml completion
kuml completion bash|zsh|fish
Prints a shell completion script, for example source <(kuml completion bash).
kuml dump-json
kuml dump-json --diagram-out <file> --layout-out <file> [--model-out <file>] <script>
Dumps the parsed diagram, its owning model and the computed layout as JSON. It is the input of the
browser-hosted wasm playground render path; --model-out is required for C4, SysML 2, BPMN and
Blueprint scripts.
Logging
All log output goes to stderr — stdout is reserved for rendered output (SVG/PNG) and
structured JSON, so it is always safe to pipe (kuml render --format svg > out.svg) or
redirect (kuml validate --output json 2>/dev/null) without a stray log line corrupting
the result.
Set KUML_LOG_LEVEL to control verbosity (default WARN). Valid values are
TRACE, DEBUG, INFO, WARN, ERROR, OFF and ALL (case-insensitive):
KUML_LOG_LEVEL=DEBUG kuml ai provider list
KUML_LOG_LEVEL can also be set as a JVM system property (-DKUML_LOG_LEVEL=DEBUG)
instead of an OS environment variable — useful when launching the CLI from a wrapper
script or a java -jar invocation that has no convenient way to export an env var. Both
channels are normalized identically; a system property takes precedence over the
environment variable if both are set, matching Logback’s own substitution lookup order.
An unset KUML_LOG_LEVEL falls back to WARN. A value outside the list above (a
plausible-but-wrong guess like SILENT, NONE or quiet) is normalized back to WARN
as well, rather than being passed through — Logback’s own parser would otherwise
silently fall back to maximum verbosity (DEBUG) for any name it doesn’t recognize,
which is the opposite of what a lower-verbosity guess like SILENT was going for. This
normalization applies the same way regardless of which channel (environment variable or
system property) the value was set through.
Third-party HTTP/AI client loggers (io.ktor, ai.koog, de.betchvaia,
aws.smithy.kotlin, software.amazon.awssdk, org.eclipse.elk, org.apache.hc,
io.netty) are intentionally pinned to WARN regardless of KUML_LOG_LEVEL —
those stacks log full request/response bodies, including Authorization headers,
at DEBUG/TRACE. Raising KUML_LOG_LEVEL only ever increases kUML’s own log
verbosity.
Exit codes
| Code | Meaning |
|---|---|
0 |
Success. |
1 |
|
2 |
Usage error (missing or invalid arguments). |
3 |
Script error (compilation or model evaluation failed). |
4 |
I/O error while reading input or writing output. |
5 |
OCL constraint violations found ( |
6 |
|
7 |
|
8 |
|
9 |
|
10 / 11 |
|
12 / 13 |
|
14 |
|
15 |
|
16 |
|
17 |
|
18 |
|
20 / 21 |
|
24 |
The requested import/export format is not available in this distribution (for example |
26 / 27 |
|
40 – 45 |
|
50 – 53 |
|
60 / 61 |
|
These codes are stable — CI scripts can branch on them.
Performance notes
The CLI compiles each script once and caches the result in the Kotlin scripting host. The first invocation is slow (cold JVM, JIT warmup, ELK initialisation) — typically 2-4 seconds. Subsequent invocations within the same JVM are sub-second.
For build pipelines that render dozens of diagrams, the Gradle plugin’s kumlRender task
is much faster: it reuses the Gradle daemon’s warm JVM and Gradle’s incremental input
checks skip unchanged files entirely.