diff --git a/README.md b/README.md
index 07e4dfe..cb4d4b4 100644
--- a/README.md
+++ b/README.md
@@ -482,6 +482,12 @@ by its parent:
 />
 ```
 
+Each of the built-in buttons has its own switch: `run` (▶; without it, the
+button still appears as ■ Stop while Python is busy, e.g. with Tests),
+`tests`, `visualization` and `resetOutput`; `repl: false` hides the REPL's
+input line but keeps the console (output, and `input()`'s line when a program
+asks). A host can thus show e.g. «Tests» without ▶, or ▶ without «Tests».
+
 With `emptyOutput: false` (the embed's `visual` mode), a visualization whose
 program prints nothing and raises no error has no output panel instead of
 «(Keine Ausgabe)», so short visualizations take less space. It is decided for
diff --git a/src/GlPythonWorkspace.tsx b/src/GlPythonWorkspace.tsx
index 0193b26..ce6076a 100644
--- a/src/GlPythonWorkspace.tsx
+++ b/src/GlPythonWorkspace.tsx
@@ -179,7 +179,10 @@ type WorkspaceCapabilities = {
   // An input line below the output that runs Python in the namespace of the
   // last Run, e.g. to call the file's functions.
   repl: boolean
-  // A Tests button that runs the doctests in the file's docstrings.
+  // The ▶ Run button (without it, only Stop while Python is busy, e.g. with
+  // Tests), and a Tests button that runs the doctests in the file's
+  // docstrings - each on its own.
+  run: boolean
   tests: boolean
   // The visualizer's "copy → chain" button and its comments switch.
   export: boolean
@@ -213,6 +216,7 @@ const defaultWorkspaceCapabilities: WorkspaceCapabilities = {
   visualization: true,
   graphics: true,
   repl: true,
+  run: true,
   tests: true,
   export: true,
   coverage: false,
@@ -2520,7 +2524,7 @@ function GlPythonWorkspace(props: GlPythonWorkspaceProps) {
   // keeps its width as ▶ becomes ■.
   const runFromActions = () => { if (isVisualizing) exitVisualizer(); runCode() }
   const testsFromActions = () => { if (isVisualizing) exitVisualizer(); runTests() }
-  const actionsNode = workspaceCapabilities.actions ? <div className="editor-actions"><button className="run-button" onClick={showStopButton ? stopPython : isRunning ? undefined : runFromActions} aria-disabled={isRunning && !showStopButton}><span className="run-button-labels"><span aria-hidden={showStopButton}><Play size={15} fill="currentColor" /> {t.runProject}</span><span aria-hidden={!showStopButton}><Square size={13} fill="currentColor" /> {t.stop ?? 'Stop'}</span></span></button>{workspaceCapabilities.tests && <button className="secondary-button" onClick={testsFromActions} disabled={isTesting || inputRequest !== null}><FlaskConical size={15} /> {t.runTests ?? 'Tests'}</button>}{workspaceCapabilities.visualization && <button className="secondary-button" onClick={runVisualize} disabled={isRunning || isVisualizerLoading || inputRequest !== null}><Workflow size={15} /> {t.visualize}</button>}{workspaceCapabilities.resetOutput && <button className="secondary-button" onClick={resetPython}><RotateCcw size={15} /> {t.resetOutput}</button>}</div> : null
+  const actionsNode = workspaceCapabilities.actions ? <div className="editor-actions">{(workspaceCapabilities.run || showStopButton) && <button className="run-button" onClick={showStopButton ? stopPython : isRunning ? undefined : runFromActions} aria-disabled={isRunning && !showStopButton}><span className="run-button-labels"><span aria-hidden={showStopButton}><Play size={15} fill="currentColor" /> {t.runProject}</span><span aria-hidden={!showStopButton}><Square size={13} fill="currentColor" /> {t.stop ?? 'Stop'}</span></span></button>}{workspaceCapabilities.tests && <button className="secondary-button" onClick={testsFromActions} disabled={isTesting || inputRequest !== null}><FlaskConical size={15} /> {t.runTests ?? 'Tests'}</button>}{workspaceCapabilities.visualization && <button className="secondary-button" onClick={runVisualize} disabled={isRunning || isVisualizerLoading || inputRequest !== null}><Workflow size={15} /> {t.visualize}</button>}{workspaceCapabilities.resetOutput && <button className="secondary-button" onClick={resetPython}><RotateCcw size={15} /> {t.resetOutput}</button>}</div> : null
   const breadcrumbsNode = <div className="breadcrumbs"><span>{project.name}</span><span>/</span><strong>{selectedFile.path}</strong></div>
   const visualizerBarNode = <div className="visualizer-bar">{visualTraceSteps.length > 0 ? <><div className="visualizer-controls"><button type="button" className="icon-button small" aria-label={t.visualizerFirstStep ?? t.visualizerRestart} title={t.visualizerFirstStep ?? t.visualizerRestart} onClick={visualFirstStep} disabled={clampedStepIndex === -1}><SkipBack size={15} /></button><button type="button" className="icon-button small" aria-label={t.visualizerPrevStep} title={t.visualizerPrevStep} onClick={visualStepBack} disabled={clampedStepIndex === -1}><ChevronLeft size={15} /></button><button type="button" className="icon-button small" aria-label={t.visualizerNextStep} title={t.visualizerNextStep} onClick={visualStepForward} disabled={clampedStepIndex >= visualTraceSteps.length - 1}><ChevronRight size={15} /></button><button type="button" className="icon-button small" aria-label={t.visualizerLastStep ?? 'Last step'} title={t.visualizerLastStep ?? 'Last step'} onClick={visualLastStep} disabled={clampedStepIndex >= visualTraceSteps.length - 1}><SkipForward size={15} /></button></div><div className="visualizer-scrubber-track"><input className="visualizer-scrubber" type="range" min={-1} max={Math.max(0, visualTraceSteps.length - 1)} value={clampedStepIndex} onChange={(event) => { setVisualStepIndex(Number(event.target.value)) }} />{errorTraceStep && <span className="visualizer-scrubber-error" title={errorTraceStep.label} style={{ '--marker-position': (visualTraceSteps.indexOf(errorTraceStep) + 1) / Math.max(1, visualTraceSteps.length) } as CSSProperties} />}</div><span className="visualizer-step-count">{clampedStepIndex === -1 ? t.visualizerBeforeStart : t.visualizerStepOf(clampedStepIndex + 1, visualTraceSteps.length)}</span>{visualTrace?.truncated && <span className="visualizer-truncated-hint"><AlertTriangle size={13} />{t.visualizerTruncated}</span>}</> : <span className="visualizer-step-count">{t.visualizerNoSteps}</span>}<div className="visualizer-mode" role="group" aria-label={t.visualizerModeLabel ?? 'Display'}><button type="button" aria-pressed={effectiveMode === 'box'} onClick={() => changeVisualizerMode('box')}>{t.visualizerModeBox ?? 'Box'}</button><button type="button" aria-pressed={effectiveMode === 'substitution'} onClick={() => changeVisualizerMode('substitution')}>{t.visualizerModeSubstitution ?? 'Substitution'}</button>{workspaceCapabilities.tree && <button type="button" aria-pressed={effectiveMode === 'tree'} onClick={() => changeVisualizerMode('tree')}>{t.visualizerModeTree ?? 'Tree'}</button>}</div><OptionsMenu label={t.visualizerOptions ?? 'Options'}><button type="button" role="menuitemcheckbox" aria-checked={animationsEnabled} className="visualizer-options-item" onClick={() => setAnimationsEnabled((enabled) => !enabled)}><span className="visualizer-options-check" aria-hidden="true" />{t.visualizerAnimate}</button>{workspaceCapabilities.listTree && <button type="button" role="menuitemcheckbox" aria-checked={showListTrees} className="visualizer-options-item" onClick={() => setShowListTrees((shown) => !shown)}><span className="visualizer-options-check" aria-hidden="true" />{t.visualizerListTrees ?? 'Show lists as trees'}</button>}{workspaceCapabilities.export && <><button type="button" role="menuitemcheckbox" aria-checked={chainComments} className="visualizer-options-item" onClick={() => changeChainComments(!chainComments)}><span className="visualizer-options-check" aria-hidden="true" />{t.copyChainComments ?? 'Comments'}</button><button type="button" role="menuitem" className="visualizer-options-item visualizer-chain-copy" onClick={copyEvaluationChain} disabled={!canCopyChain}><Copy size={14} aria-hidden="true" />{chainFeedback === 'copied' ? (t.copyChainDone ?? 'Copied') : chainFeedback === 'failed' ? (t.copyChainFailed ?? 'Could not copy') : (t.copyChain ?? 'Copy \u2192 chain')}</button></>}</OptionsMenu>{workspaceCapabilities.exitVisualizer && <button type="button" className="icon-button small visualizer-exit" aria-label={t.exitVisualizer} title={t.exitVisualizer} onClick={exitVisualizer}><X size={16} /></button>}</div>
   const visualizerWarningNode = <>{isVisualizing && visualTrace?.error && !errorTraceStep && <div className="visualizer-warning"><AlertTriangle size={14} />{t.visualizerError(visualTrace.error)}</div>}</>