Visualization options reference

pyfcstm plantuml and pyfcstm visualize share the same PlantUML source configuration. plantuml stops after writing PlantUML source. visualize uses the same source configuration, then renders an image or PDF through a PlantUML backend. Use Visualization tasks for task recipes and this page for exact option facts.

The synchronization markers below are comments consumed by tools/check_visualization_reference_docs.py. They cover every PlantUMLOptions field plus CLI renderer, type, environment, parser, and failure-boundary facts.

Mental model

Visualization has two independent layers:

1. PlantUML source layer. PlantUMLOptions decides which model facts are visible in the generated PlantUML text: variables, lifecycle actions, guards, effects, events, state labels, hierarchy depth, and styling.

2. Rendered artifact layer. visualize chooses a renderer backend, file type, output path, and viewer behavior. These settings do not change the model facts in the PlantUML source; they only decide how the source becomes png, svg, or pdf.

Reference-grade option scenarios

The reference tables below are exhaustive by field, but field rows alone do not show how options combine. These scenarios pin the most common combinations to observable outcomes and failure boundaries.

Option scenarios and boundaries

Scenario	Example	Expected effect	Boundary or counterexample
Preset-only source export.	pyfcstm plantuml -i docs/source/tutorials/visualization/example.fcstm -l minimal -o /tmp/minimal.puml	Uses the minimal preset for source text and writes no image.	Passing -t svg to plantuml is invalid because render type belongs to visualize.
Preset plus narrow override.	pyfcstm plantuml -i docs/source/tutorials/visualization/example.fcstm -l full -c max_action_lines=3 -o /tmp/compact.puml	Keeps full visibility while limiting each action block to three visible lines.	-c detail_level=full is the wrong layer; use -l full for the preset.
Event-oriented diagram.	pyfcstm plantuml -i docs/source/tutorials/visualization/example.fcstm -c event_visualization_mode=both -o /tmp/events.puml	Shows events directly in transitions and in event-supporting visual structures.	Invalid enum values fail during option parsing before a renderer is called.
Headless render.	pyfcstm visualize -i docs/source/tutorials/visualization/example.fcstm -t svg -o /tmp/example.svg --no-open	Writes an SVG and skips desktop viewer launch.	Without --no-open, GUI availability can affect the final open step even after rendering succeeds.
Local renderer privacy.	pyfcstm visualize -i docs/source/tutorials/visualization/example.fcstm --renderer local -p ./plantuml.jar --no-open	Keeps PlantUML source on the local machine when Java and the jar are available.	Missing jar or Java is a local backend failure, not a model or PlantUML-option failure.
Remote renderer convenience.	pyfcstm visualize -i docs/source/tutorials/visualization/example.fcstm --renderer remote --no-open	Sends PlantUML source to the configured remote host and writes the rendered artifact.	Do not use for private diagrams unless sending the source to that host is acceptable.

Detail presets

The -l / --level CLI option maps to PlantUMLOptions.detail_level. Use it for the main audience choice, then add -c key=value overrides only for specific deviations.

Detail presets

Preset	Resolved defaults	Best use
minimal	Shows variable definitions, transition guards, transition effects, and events. Hides lifecycle actions and pseudo-state styling.	Presentations and architecture views where state shape matters more than implementation detail.
normal	Shows variable definitions, transition guards, transition effects, events, and pseudo-state styling. Hides lifecycle actions.	General documentation, code review, and quick model understanding.
full	Shows variable definitions, lifecycle actions, transition guards, transition effects, events, and pseudo-state styling.	Deep debugging, semantic review, and generated-runtime alignment discussion.

Preset examples:

pyfcstm plantuml -i machine.fcstm -l minimal -o machine.minimal.puml
pyfcstm plantuml -i machine.fcstm -l normal -o machine.normal.puml
pyfcstm plantuml -i machine.fcstm -l full -o machine.full.puml

PlantUML option fields

Options with default None are resolved by PlantUMLOptions.to_config(). Resolution order is: explicit value, parent switch, detail preset, then final fallback. Parent switches are especially important for lifecycle actions: show_enter_actions, show_during_actions, show_exit_actions, show_aspect_actions, show_abstract_actions, and show_concrete_actions inherit from show_lifecycle_actions when they are None.

Complete PlantUMLOptions field map

Field	CLI form	Default	Values	Effect and notes
detail_level	-l minimal|normal|full	normal	minimal, normal, full	Main preset. Use -l on the CLI; do not pass -c detail_level=... because the command already passes the preset separately.
show_variable_definitions	-c show_variable_definitions=true	None	bool or None in Python	Show the def variable inventory. None resolves from the preset.
variable_display_mode	-c variable_display_mode=legend	legend	note, legend, hide	Choose whether variables appear as a PlantUML note, a legend table, or not at all.
variable_legend_position	-c 'variable_legend_position=bottom right'	top left	top left, top center, top right, bottom left, bottom center, bottom right, left, right, center	Position for variable legends. Quote the shell argument when the value contains a space.
state_name_format	-c state_name_format=extra_name,name	('extra_name',)	tuple of name, extra_name, path	Components for state labels. The first visible component is primary; additional components appear in parentheses.
show_pseudo_state_style	-c show_pseudo_state_style=true	None	bool or None in Python	Apply pseudo-state visual styling. minimal resolves this to False; normal and full resolve it to True.
collapse_empty_states	-c collapse_empty_states=true	False	bool	Compact states with no visible action text.
show_lifecycle_actions	-c show_lifecycle_actions=true	None	bool or None in Python	Master switch for enter, during, exit, aspect, abstract, and concrete action visibility.
show_enter_actions	-c show_enter_actions=true	None	bool or None in Python	Show only enter actions when overriding the lifecycle parent switch.
show_during_actions	-c show_during_actions=true	None	bool or None in Python	Show during actions when visible lifecycle details are needed.
show_exit_actions	-c show_exit_actions=true	None	bool or None in Python	Show exit actions.
show_aspect_actions	-c show_aspect_actions=true	None	bool or None in Python	Show >> during before and >> during after aspect actions.
show_abstract_actions	-c show_abstract_actions=true	None	bool or None in Python	Show abstract lifecycle actions, often useful for integration surfaces.
show_concrete_actions	-c show_concrete_actions=true	None	bool or None in Python	Show concrete operation bodies, often useful for implementation review.
abstract_action_marker	-c abstract_action_marker=symbol	text	text, symbol, none	Render abstract actions as text, a guillemet marker, or without an abstract marker.
max_action_lines	-c max_action_lines=3	None	integer or None in Python	Limit visible lines per action. Use this when full diagrams become too tall.
show_transition_guards	-c show_transition_guards=false	None	bool or None in Python	Show or hide transition guard conditions.
show_transition_effects	-c show_transition_effects=false	None	bool or None in Python	Show or hide transition effect blocks.
transition_effect_mode	-c transition_effect_mode=inline	note	note, inline, hide	Choose note-on-link effects, compact inline effects, or hidden effects.
show_events	-c show_events=false	None	bool or None in Python	Show or hide event names on transitions.
event_name_format	-c event_name_format=extra_name,relpath	('extra_name', 'relpath')	tuple of name, extra_name, path, relpath	Components for event labels. path is absolute; relpath follows the transition’s event reference when available.
event_visualization_mode	-c event_visualization_mode=both	none	none, color, legend, both, dependency_view	Add event colors, an event legend, both, or no special event visualization. dependency_view is reserved and should not be used as a normal diagram mode.
event_legend_position	-c event_legend_position=right	right	same position labels as variable_legend_position	Position for the event legend when event legend output is enabled.
max_depth	-c max_depth=2	None	integer or None in Python	Limit expanded hierarchy depth and insert a collapsed-state marker below the limit.
collapsed_state_marker	-c collapsed_state_marker='[more]'	...	string	Text shown for collapsed descendants when max_depth hides deeper states.
use_skinparam	-c use_skinparam=false	True	bool	Include or omit the pyfcstm PlantUML style block.
use_stereotypes	-c use_stereotypes=false	True	bool	Include or omit PlantUML stereotypes such as <<pseudo>> and <<composite>>.
custom_colors	Python API only	None	mapping or None	Custom event color mapping for color and both event modes. The CLI does not parse dictionaries for this option.

Field and renderer example cards

The table above gives the closed field list. The cards below show how groups of fields interact in real commands. They are intentionally repetitive: each row gives a concrete command, the expected source or rendering signal, and the reason to choose or avoid it.

Preset resolution examples

Examples

Use case	Command	Expected effect	Selection rule
Minimal structure review	pyfcstm plantuml -i machine.fcstm -l minimal -o machine.min.puml	Shows hierarchy, variables, transition guards/effects, and events; hides lifecycle action text and pseudo-state styling.	Use for architecture discussion where implementation bodies would distract.
Normal documentation view	pyfcstm plantuml -i machine.fcstm -l normal -o machine.normal.puml	Adds pseudo-state styling while keeping lifecycle actions hidden.	Use for most documentation and review snippets.
Full semantic review	pyfcstm plantuml -i machine.fcstm -l full -o machine.full.puml	Shows lifecycle action families and concrete/abstract action visibility controlled by the detail preset.	Use for semantic review, generated-runtime alignment, or debugging.
Override after preset	pyfcstm plantuml -i machine.fcstm -l minimal -c show_lifecycle_actions=true -o machine.min-actions.puml	Explicit value wins over preset defaults.	Use sparingly when a mostly minimal diagram needs one semantic dimension.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Variable and state label examples

Examples

Use case	Command	Expected effect	Selection rule
Legend variables	pyfcstm plantuml -i machine.fcstm -c variable_display_mode=legend -o machine.vars.puml	Variable definitions render in a PlantUML legend.	Good when variables are global context for the whole diagram.
Hide variables	pyfcstm plantuml -i machine.fcstm -c variable_display_mode=hide -o machine.no-vars.puml	Variable inventory is removed from the source.	Good for structure-only diagrams.
Dual state labels	pyfcstm plantuml -i machine.fcstm -c state_name_format=extra_name,name -o machine.labels.puml	State labels include both readable extra name and raw model name.	Good when generated identifiers and DSL names both matter.
Collapsed depth	pyfcstm plantuml -i machine.fcstm -c max_depth=2 -c collapsed_state_marker="[more]" -o machine.depth.puml	Descendants beyond depth are replaced by the marker.	Good for large hierarchical models.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Lifecycle visibility examples

Examples

Use case	Command	Expected effect	Selection rule
Master lifecycle switch	pyfcstm plantuml -i machine.fcstm -c show_lifecycle_actions=true -o machine.lifecycle.puml	Enter, during, exit, aspect, abstract, and concrete action families inherit visible defaults.	Use when lifecycle ordering is part of review.
Only abstract hooks	pyfcstm plantuml -i machine.fcstm -c show_lifecycle_actions=false -c show_abstract_actions=true -o machine.hooks.puml	Abstract extension points remain visible while concrete bodies stay hidden.	Use for integration-surface reviews.
Limit action text	pyfcstm plantuml -i machine.fcstm -l full -c max_action_lines=3 -o machine.short-actions.puml	Long action bodies are clipped after the configured line count.	Use when full diagrams become too tall.
Aspect-only review	pyfcstm plantuml -i machine.fcstm -c show_lifecycle_actions=false -c show_aspect_actions=true -o machine.aspects.puml	Descendant-cycle before/after aspects are visible without other lifecycle bodies.	Use when reviewing cross-cutting behavior.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Transition and event examples

Examples

Use case	Command	Expected effect	Selection rule
Hide guards	pyfcstm plantuml -i machine.fcstm -c show_transition_guards=false -o machine.no-guards.puml	Transition labels omit guard conditions.	Use only when guards are not relevant to the audience.
Inline effects	pyfcstm plantuml -i machine.fcstm -c transition_effect_mode=inline -o machine.inline-effects.puml	Transition effects appear compactly on the transition instead of note blocks.	Use for small effect bodies.
Event legend	pyfcstm plantuml -i machine.fcstm -c event_visualization_mode=legend -o machine.event-legend.puml	Events get a legend without coloring transitions.	Use when event names repeat often.
Event colors and legend	pyfcstm plantuml -i machine.fcstm -c event_visualization_mode=both -o machine.event-colors.puml	Events are colored and listed in the legend.	Use for event-flow diagrams.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Renderer and environment examples

Examples

Use case	Command	Expected effect	Selection rule
Source-only export	pyfcstm plantuml -i machine.fcstm -o machine.puml	No renderer is checked or used.	Safe even when Java or network rendering is unavailable.
Backend check	pyfcstm visualize --check --renderer auto	Reports local and remote availability and exits without parsing DSL.	Use before CI rendering jobs.
Cache output	pyfcstm visualize -i machine.fcstm --no-open	Writes to the pyfcstm visualize cache when -o is omitted.	Use only for local preview, not reproducible build outputs.
Strict open	pyfcstm visualize -i machine.fcstm --strict-open	Viewer launch failure becomes command failure.	Use only for desktop workflows that require opening the image.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Invalid value examples

Examples

Use case	Command	Expected effect	Selection rule
Unknown field	pyfcstm plantuml -i machine.fcstm -c does_not_exist=true	Fails because the key is not a PlantUMLOptions field.	Check the complete field table.
Wrong integer	pyfcstm plantuml -i machine.fcstm -c max_depth=abc	Fails because max_depth expects an integer or None.	Use a number such as 2.
Wrong render type suffix	pyfcstm visualize -i machine.fcstm -o machine.svg -t png --no-open	Fails before rendering because suffix and type disagree.	Use -o machine.png or -t svg.
Private source over remote	pyfcstm visualize -i private.fcstm --renderer remote --no-open	This may succeed but sends PlantUML source to a service.	Use local rendering for private diagrams.

Review note:

If the command changes source visibility, verify the generated .puml. If it changes rendering behavior, verify visualize --check or the rendered artifact path.

Resolution trace: lifecycle actions

Lifecycle visibility is the most common place where users misread the option model. The resolved value is not simply the dataclass default:

1. An explicit child switch such as show_enter_actions=false wins first.

2. If the child switch is None, it inherits from show_lifecycle_actions when that parent switch is explicit.

3. If the parent switch is also None, the selected detail preset supplies the default.

4. Final fallback values are applied only after those steps.

Lifecycle resolution examples

Input	Resolved meaning	Reader-visible result
-l minimal	lifecycle parent and child switches resolve false.	lifecycle text is hidden.
-l full	lifecycle parent and child switches resolve true.	enter/during/exit/aspect/abstract/concrete actions are visible unless another option hides them.
-l full -c show_concrete_actions=false	concrete body visibility is explicitly false; other full preset action groups remain visible.	abstract hooks can remain visible while implementation bodies are hidden.
-c show_lifecycle_actions=false -c show_enter_actions=true	explicit child switch overrides explicit parent switch for enter actions.	enter actions are visible even though other lifecycle groups remain hidden.

Per-field scenario matrix

The complete field map above is intentionally closed-list. The matrix below is more practical: every public field gets two normal examples and one boundary example. Use it when a review needs to prove that a diagram choice is deliberate rather than accidental.

Source visibility and label fields

Field	Example A	Example B	Boundary or counterexample
detail_level	-l minimal for a small hierarchy review.	-l full when lifecycle actions are the topic.	Do not pass -c detail_level=full on the CLI; use -l.
show_variable_definitions	-c show_variable_definitions=true to prove variable declarations in a review.	-c show_variable_definitions=false for a structure-only diagram.	variable_display_mode=hide also hides variables even when this switch is true.
variable_display_mode	legend keeps variables compact for documentation pages.	note makes variables stand out near the state graph.	hide is not a position; it suppresses variable output.
variable_legend_position	top left leaves right-side event legends free.	bottom right works when the top of the diagram is dense.	Quote values containing spaces in shells.
state_name_format	extra_name shows the display label when available.	extra_name,name keeps both human label and DSL identifier.	path can make large diagrams noisy; reserve it for ambiguity removal.
show_pseudo_state_style	true makes pseudo states visually distinct in normal/full diagrams.	false keeps minimal diagrams less stylized.	It affects styling only, not whether pseudo states exist in the model.
collapse_empty_states	true shortens states with no visible action text.	false keeps normal PlantUML state blocks for readability.	If lifecycle details are hidden, a state may become visually empty even though it has hidden actions.
max_depth	1 keeps only root-level structure for a high-level review.	2 shows one nested layer while hiding deeper details.	It hides diagram detail only; it does not delete model states.
collapsed_state_marker	... is compact and neutral.	[hidden children] is explicit for documentation readers.	The marker appears only when max_depth actually collapses descendants.

Lifecycle and action fields

Field	Example A	Example B	Boundary or counterexample
show_lifecycle_actions	true when entry/during/exit order is the review target.	false when transitions and hierarchy matter more than action bodies.	Child switches override it only when they are explicitly set.
show_enter_actions	true with show_lifecycle_actions=false to spotlight initialization hooks.	false with show_lifecycle_actions=true to hide noisy entry details.	None in Python means inherit, not false.
show_during_actions	true for cycle-behavior reviews.	false when only transitions should be emphasized.	Aspect during hooks are governed separately by show_aspect_actions.
show_exit_actions	true when cleanup behavior is important.	false for compact state inventories.	Hiding exit actions does not hide transition effects.
show_aspect_actions	true to show >> during before and >> during after hooks.	false when leaf-local actions are enough for the reader.	It is about aspect hooks, not ordinary transition guards.
show_abstract_actions	true when generated-code integration hooks must be visible.	false when only concrete operations are being audited.	It filters action visibility after lifecycle visibility has allowed the action group.
show_concrete_actions	true to audit assignments and operation bodies.	false to show only abstract extension points.	It does not change generated runtime behavior.
abstract_action_marker	text preserves the DSL word abstract.	symbol uses a compact «abstract» marker.	none can hide the distinction; use it only when the caption explains the choice.
max_action_lines	3 keeps long actions readable in a normal diagram.	1 shows only the first line as a locator.	0 or None does not provide a useful line cap in the same way as a positive integer.

Transition, event, and styling fields

Field	Example A	Example B	Boundary or counterexample
show_transition_guards	true for reachability and condition review.	false for a pure topology diagram.	Hiding guards can make mutually exclusive paths look ambiguous.
show_transition_effects	true when variable updates matter.	false for compact routing diagrams.	Effects may still exist in the model even if hidden from the diagram.
transition_effect_mode	note keeps long effects off the edge label.	inline is compact for short assignments.	hide suppresses effect text even when effects are present.
show_events	true to explain event-triggered transitions.	false for diagrams focused only on possible movement.	Event colors and legends are not useful if events are hidden.
event_name_format	extra_name,relpath is compact and user-facing.	name,path is useful when absolute ownership matters.	relpath depends on the transition’s event reference when available.
event_visualization_mode	color colors event families without adding a legend.	both uses colors plus legend for documentation.	dependency_view is reserved and should not be treated as the normal event mode.
event_legend_position	right keeps event explanations beside the graph.	bottom center works for wide diagrams.	It matters only when event legend output is enabled.
use_skinparam	true applies pyfcstm’s default PlantUML styling.	false lets a downstream PlantUML theme own styling.	Turning it off can make pseudo/composite distinctions less visible.
use_stereotypes	true emits stereotypes such as <<pseudo>>.	false produces plainer PlantUML source.	Some style rules depend on stereotypes, so disabling them can change visual meaning.
custom_colors	Python API code can map event groups to stable colors.	Use it for a publication diagram that must match a legend palette.	The CLI cannot parse dictionary values for this field.

Renderer and environment decision fields

Decision	Example A	Example B	Boundary or counterexample
Render type	-t svg for scalable documentation.	-t png for screenshots or quick previews.	The output suffix must match the type when a suffix is provided.
Renderer mode	--renderer local for private diagrams.	--renderer remote when an approved service owns rendering.	--renderer auto may fall back to remote after local failure.
Local backend paths	-j /usr/bin/java fixes the Java executable.	-p ./plantuml.jar fixes the PlantUML jar.	These options do not affect remote rendering.
Remote backend host	-r http://www.plantuml.com/plantuml uses the public default explicitly.	PLANTUML_HOST=https://plantuml.internal/plantuml uses an internal service.	Remote rendering sends source text to that host.
Viewer behavior	--no-open is the stable scripted form.	--strict-open is appropriate only when opening the viewer is itself required.	CI, PYFCSTM_NO_GUI, and missing display variables can skip ordinary --open.

Typed -c value syntax

The CLI accepts repeated -c key=value arguments and parses values with the same helper used by other pyfcstm configuration paths.

Value forms

Form	Examples	Result	Notes
bool	true, yes, 1, false, no, 0	Python bool	For bool-typed fields, only these forms are accepted.
int	3, 0	Python int	Used by max_depth and max_action_lines.
float	1.5	Python float	Auto parser supports floats, though current PlantUML CLI fields do not require float-specific options.
quoted string	'variable_legend_position=bottom right'	Python str	Quote the entire shell argument when spaces are part of the value.
none/null	none, null	Python None in auto mode or None-typed fields	Most CLI fields use explicit concrete types, so None is mainly a Python API pattern.
tuple	state_name_format=extra_name,name	tuple of strings	Used by state_name_format and event_name_format.
optional value	omitted option, or explicit None in Python	inherited/resolved value	Optional booleans resolve through parent switches and presets.
invalid key	-c does_not_exist=true	command failure	Unknown keys reach PlantUMLOptions construction and are rejected.
invalid value	-c max_depth=abc	command failure	Type-specific parsing reports the offending key.

CLI examples:

pyfcstm plantuml -i machine.fcstm -c show_events=true -c max_depth=2
pyfcstm plantuml -i machine.fcstm -c state_name_format=extra_name,name
pyfcstm plantuml -i machine.fcstm -c 'variable_legend_position=bottom right'

Python API examples:

from pyfcstm.model.plantuml import PlantUMLOptions

api_surface = PlantUMLOptions(
    detail_level='full',
    show_concrete_actions=False,
    show_abstract_actions=True,
    abstract_action_marker='symbol',
)

event_view = PlantUMLOptions(
    event_visualization_mode='both',
    custom_colors={'System.Start': '#00AA00'},
)

Renderer and file options

These options belong to visualize only. They do not affect PlantUML source content.

Renderer and file facts

Fact	Values	Meaning
Renderer mode	local, remote, auto	local uses Java plus a PlantUML jar; remote uses a PlantUML server; auto tries local then remote.
Render type	png, svg, pdf	Output file type. The output suffix must match the selected type when a suffix is provided.
Cache path	platform-specific	Used when visualize -o is omitted. Linux honors XDG_CACHE_HOME; Windows honors LOCALAPPDATA.
Check mode	pyfcstm visualize --check	Checks renderer availability and exits without parsing a DSL file.
Open mode	--open / --no-open / --strict-open	Controls viewer launch after rendering. Headless environments skip viewer launch unless strict mode is requested.

Environment variables

Environment variables

Variable	Used by	Meaning
PLANTUML_JAR	visualize --renderer local	Default PlantUML jar path when -p / --plantuml-jar is omitted.
PLANTUML_HOST	visualize --renderer remote	Default remote PlantUML server when -r / --remote-host is omitted.
PYFCSTM_NO_GUI	visualize --open	Truthy value disables automatic viewer launch.
CI	visualize --open	Truthy value marks the environment as headless.
DISPLAY / WAYLAND_DISPLAY / MIR_SOCKET	Linux viewer detection	At least one normally indicates a graphical session on Linux.
XDG_CACHE_HOME	Linux cache output	Base directory for omitted visualize -o outputs.
LOCALAPPDATA	Windows cache output	Base directory for omitted visualize -o outputs on Windows.

Behavior boundaries

Boundary facts

Boundary	Exact behavior
renderer-auto-fallback	auto tries local rendering first and falls back to remote rendering only if local backend creation/check fails.
suffix-mismatch	visualize -o diagram.svg -t png fails before rendering because .svg does not match png.
check-mode	--check does not require -i and does not parse any DSL file.
headless-open	In headless environments, normal --open prints a skip message and keeps a successful render successful.
strict-open	--strict-open turns viewer-launch failure or headless skip into a command failure.
remote-privacy	Remote rendering sends the generated PlantUML source to the configured service. Use local rendering for private diagrams.
cache-output	Omitted -o writes to the pyfcstm visualize cache instead of the current directory.
local-backend-failure	Local failures name the local renderer and include the underlying plantumlcli/Java/path error class when available.
remote-network-failure	Remote failures name the remote renderer and include the underlying network/request error when available.
backend-success-without-output	If plantumlcli reports success but no file is created, pyfcstm treats it as a failure.
source-only-plantuml	plantuml never renders an image and never checks renderer availability.
rendered-image-visualize	visualize always goes through PlantUML source first, then renders the requested artifact type.