diff --git a/STUMBLES.md b/STUMBLES.md
index c7cf39412..d4c9e1370 100644
--- a/STUMBLES.md
+++ b/STUMBLES.md
@@ -9,9 +9,10 @@ por impacto.
 
 El Knob del ejercicio **ya está construido de verdad** en las 5 capas
 (morfo/langs/sema/soma/eidos, `c13cad74`) con demo (`8dfd3505`) — lo que valida
-el ejercicio: 8 de 9 cerrados; de **#7** (contrato CSS-vars soma→eidos) se cerró
-la dirección recipe→tema con un guard (opción C, cazó 3 fantasmas reales), y
-queda solo el sub-contrato provider→recipe (opción A, opcional).
+el ejercicio: **los 9 cerrados**. De **#7** (contrato CSS-vars soma→eidos):
+recipe→tema con un guard (opción C, cazó 3 fantasmas reales) y provider→recipe
+con la opción A1 fiel a la arquitectura — el morfo declara `cssVars` (fuente de
+verdad) y un guard verifica que provider y recipe honran cada declaración.
 
 | # | Tropiezo | Estado | Cómo |
 |---|---|---|---|
@@ -21,7 +22,7 @@ queda solo el sub-contrato provider→recipe (opción A, opcional).
 | 4 | Doctrina `trigger()` continuo sin cerrar | ✅ RESUELTO | sección `## Continuous components` en `sema.md` (`1da36ca6`), fact-check adversarial |
 | 5 | Falta condición `part-absent` | ✅ RESUELTO | `{ when: 'part-absent', part }` en morfo (`11504043`); el morfo del Knob la usa |
 | 6 | Formato de `langs/components/{kebab}.ts` | ✅ RESUELTO | forma `LangNode` (`{ key: { es, en } }`, anidable, `satisfies`) documentada en morfo/soma/checklist |
-| 7 | CSS-vars del provider sin contrato | 🟡 CASI | dirección **recipe→tema** guardada (opción C: guard de fantasmas de tema en `recipe-css-contract` — pilló 3 bugs reales); queda solo el sub-contrato **provider→recipe** (opción A, opcional) |
+| 7 | CSS-vars del provider sin contrato | ✅ RESUELTO | **recipe→tema**: guard de fantasmas de tema (opción C — pilló 3 bugs reales); **provider→recipe**: opción A1 (fiel a la arquitectura) — campo `cssVars` en el morfo (fuente de verdad) + guard "provider escribe Y recipe lee cada var declarada" |
 | 8 | Docs imprescindibles fuera del paquete | ✅ RESUELTO | `component-audit.md §0` lista el paquete mínimo como archivos exactos |
 | 9 | Fricciones menores (docs) | ✅ RESUELTO | `### Authoring notes` en `soma.md` §6: `state<T>()` vs `$state`, `role` opcional en Provider, `Without<>`/`PrimitiveDivAttributes`, ownership de pointermove/up del gesture |
 
@@ -140,8 +141,17 @@ selectors vía `style` no, pero soma+eidos ya son 2).
 > cross-check da ~17 falsos positivos. **Solo A1 lo cierra**: declarar
 > `cssVars: [...]` en el morfo (fuente de verdad de qué vars SON el contrato) +
 > guard "el provider escribe cada `cssVar` declarada" (un rename deja de
-> escribir la declarada → se detecta). Coste: morfo types+schema+compile +
-> declarar en cada morfo con vars publicadas + guard. Pendiente de decisión.
+> escribir la declarada → se detecta).
+>
+> **A1 implementado (2026-07-03), fiel a la arquitectura (el usuario: "la fuente
+> de verdad por diseño es el morfo").** `MorfoCssVar` + campo `cssVars?` en el
+> tipo `Morfo` (types) + schema + `compile` lo expone en `contracts.cssVars`
+> (`--{kebab}-{name}`); el morfo del Knob declara `progress`/`angle`; guard nuevo
+> en `recipe-css-contract.test.ts` verifica **ambos lados** — el provider escribe
+> `--{kebab}-{name}` Y el recipe lo lee — enumerando morfos con `import.meta.glob`.
+> Probado no-vacío (una cssVar bogus se caza en ambos lados). Resuelve la
+> ambigüedad de A2: en el CSS una var escrita-por-provider y un alias-de-consumidor
+> son idénticas; la declaración del morfo es lo que las distingue.
 
 ## 8. Dos docs imprescindibles no estaban en el paquete
 
diff --git a/docs/architecture/morfo.md b/docs/architecture/morfo.md
index bf7a52bbd..4c5255b20 100644
--- a/docs/architecture/morfo.md
+++ b/docs/architecture/morfo.md
@@ -528,6 +528,28 @@ string is not duplicated across Drawer, Dialog, Popover, Toast, etc. Use
 `v.langRef` for an app/system namespace that is deliberately not owned by
 the component.
 
+### Step 4.6 — Optional: declare provider→eidos CSS vars (`cssVars`)
+
+When a soma provider publishes a **functional** CSS custom property at runtime
+(writing it into an inline `style` for the eidos recipe to consume — e.g. Knob's
+`--knob-progress` / `--knob-angle`, Drawer's `--drawer-progress`), declare it in
+`cssVars`. The full property is `--{kebab}-{name}`.
+
+```ts
+cssVars: [
+	{ name: 'progress', description: '0–1 value fraction; drives the conic value arc' },
+	{ name: 'angle', description: 'pointer rotation in degrees; drives the indicator' }
+],
+```
+
+Declaring it makes the **soma→eidos functional-var surface part of the
+contract**: a guard (`recipe-css-contract.test.ts`) verifies the provider writes
+each declared var *and* the recipe reads it, so renaming one side without the
+other fails loudly instead of degrading silently to a `var()` fallback (STUMBLES
+#7). Declare only the vars that are the contract (written by the provider **and**
+read by the recipe) — not public `--{kebab}-*` aliases the *consumer* may
+override, nor recipe-internal `--_{kebab}-*` privates.
+
 ### Step 5 — Optional: keyboard and focus
 
 ```ts
diff --git a/src/uix/eidos/recipe-css-contract.test.ts b/src/uix/eidos/recipe-css-contract.test.ts
index e3e329153..34f22e3c8 100644
--- a/src/uix/eidos/recipe-css-contract.test.ts
+++ b/src/uix/eidos/recipe-css-contract.test.ts
@@ -268,6 +268,54 @@ describe('Eidos recipe CSS contract', () => {
 		expect([...new Set(phantoms)].sort()).toEqual([])
 	})
 
+	// Provider→recipe CSS-var contract (STUMBLES #7, option A — the architecture-
+	// faithful close). The MORFO is the source of truth: `cssVars` declares the
+	// functional custom properties the soma provider writes and the eidos recipe
+	// reads. This guard verifies BOTH sides honour each declaration — the provider
+	// writes `--{kebab}-{name}` and the recipe reads it — so renaming one side
+	// without the other fails loudly instead of silently degrading to a fallback
+	// (exactly how the Knob's `--knob-angle` / `--knob-progress` would have
+	// drifted). A grep-only cross-check can't do this: in the CSS a provider-
+	// written var and a consumer-override alias are indistinguishable — the morfo
+	// declaration is what disambiguates.
+	it('honours the morfo cssVars contract on both sides (soma writes, eidos reads)', async () => {
+		const morfoLoaders = import.meta.glob('../morfo/components/*.ts')
+		const problems: string[] = []
+		for (const [path, load] of Object.entries(morfoLoaders)) {
+			if (path.includes('.test.')) continue
+			const mod = (await load()) as Record<string, unknown>
+			for (const exported of Object.values(mod)) {
+				const morfo = exported as { kebab?: unknown; cssVars?: unknown }
+				if (typeof morfo?.kebab !== 'string') continue
+				const cssVars = morfo.cssVars
+				if (!Array.isArray(cssVars) || cssVars.length === 0) continue
+				const kebab = morfo.kebab
+				if (WIP_TRACKS.has(kebab)) continue
+
+				const providerDir = join('src/uix/soma/components', kebab)
+				const providerSrc = existsSync(providerDir)
+					? stripCssComments(readTextFilesRecursive(providerDir).join('\n'))
+					: ''
+				const recipePath = join(COMPONENTS_DIR, kebab, `${kebab}.css`)
+				const recipe = existsSync(recipePath) ? readFileSync(recipePath, 'utf8') : ''
+
+				for (const cssVar of cssVars as { name: string }[]) {
+					const full = `--${kebab}-${cssVar.name}`
+					// A write is `--{c}-{name}:` or `'--{c}-{name}':` (colon, maybe
+					// through a quote, follows the name); a `var(--{c}-{name})` read has
+					// `,`/`)` after it and does NOT match.
+					if (!new RegExp(`${full}['"]?\\s*:`).test(providerSrc)) {
+						problems.push(`${kebab}: morfo declares cssVar ${full} but the provider never writes it`)
+					}
+					if (!recipe.includes(`var(${full}`)) {
+						problems.push(`${kebab}: morfo declares cssVar ${full} but the recipe never reads it`)
+					}
+				}
+			}
+		}
+		expect(problems.sort()).toEqual([])
+	})
+
 	// Coherence guard (Fase 7 — theming audit): the type/size canon is only worth
 	// having if components CONSUME it. Recipe `font-size-*` / `icon-size-*` tokens
 	// MUST reference the `--font-size-*` / `--icon-size-*` scale (or another token),
diff --git a/src/uix/morfo/compile.ts b/src/uix/morfo/compile.ts
index ae7afe56d..f822f54fc 100644
--- a/src/uix/morfo/compile.ts
+++ b/src/uix/morfo/compile.ts
@@ -249,6 +249,12 @@ export interface CompiledMorfo {
 		readonly dataAttrsByPart: ReadonlyMap<string, readonly DataAttrContract[]>
 		readonly cssSelectors: readonly CssSelectorContract[]
 		readonly requiredSources: RequiredSourceContract
+		/**
+		 * Full names (`--{kebab}-{name}`) of the CSS custom properties the soma
+		 * provider writes and the eidos recipe reads. The soma→eidos functional-var
+		 * contract; empty when the morfo declares no `cssVars`.
+		 */
+		readonly cssVars: readonly string[]
 	}
 }
 
@@ -338,7 +344,8 @@ function build(morfo: Morfo): CompiledMorfo {
 				props: Object.freeze([...propSet].sort()),
 				parts: Object.freeze([...partRefSet].sort()),
 				translations: Object.freeze([...translationSet].sort())
-			})
+			}),
+			cssVars: Object.freeze((morfo.cssVars ?? []).map((v) => `--${morfo.kebab}-${v.name}`))
 		})
 	})
 
diff --git a/src/uix/morfo/components/knob.ts b/src/uix/morfo/components/knob.ts
index 3eaee0640..35e8a6b00 100644
--- a/src/uix/morfo/components/knob.ts
+++ b/src/uix/morfo/components/knob.ts
@@ -26,6 +26,13 @@ export const knobMorfo = {
 		'control.roledescription': '#?components.knob.control.roledescription|rotary knob'
 	},
 
+	// Functional CSS vars the provider publishes (on the Control) and the eidos
+	// recipe consumes — the soma→eidos contract surface (STUMBLES #7).
+	cssVars: [
+		{ name: 'progress', description: '0–1 value fraction; drives the conic value arc' },
+		{ name: 'angle', description: 'pointer rotation in degrees; drives the indicator' }
+	],
+
 	parts: [
 		{
 			name: 'Provider',
diff --git a/src/uix/morfo/schema.ts b/src/uix/morfo/schema.ts
index 57a08b111..1e0344f00 100644
--- a/src/uix/morfo/schema.ts
+++ b/src/uix/morfo/schema.ts
@@ -351,6 +351,11 @@ const semaExpressionModeSchema = union(
 	literal('none')
 );
 
+const cssVarSchema = object({
+	name: string(),
+	description: optional(string())
+});
+
 const morfoShallowSchema = object(
 	{
 		name: string(),
@@ -360,6 +365,7 @@ const morfoShallowSchema = object(
 		focus: optional(focusSchema),
 		events: optional(array(eventSchema)),
 		expression: optional(semaExpressionModeSchema),
+		cssVars: optional(array(cssVarSchema)),
 		translations: optional(object({}, { unknownKeys: 'passthrough' })),
 		parts: array(object({}, { unknownKeys: 'passthrough' }))
 		// ^ parts are opaque here; walker recurses with `partShallowSchema`
diff --git a/src/uix/morfo/types.ts b/src/uix/morfo/types.ts
index e42d02978..a5d32b849 100644
--- a/src/uix/morfo/types.ts
+++ b/src/uix/morfo/types.ts
@@ -831,6 +831,20 @@ export type SemaExpressionMode = 'pack' | 'family-default' | 'delegated' | 'none
  * Props live in the component's `types.ts` with JSDoc. Component-owned
  * text slots live in `texts`.
  */
+/**
+ * A CSS custom property the component's soma provider writes at runtime (into an
+ * inline `style`) and its eidos recipe consumes via `var(...)`. This is the
+ * soma→eidos functional-var contract — the surface that, before being declared
+ * here, drifted silently when either side renamed the property (STUMBLES #7).
+ * The full property is `--{kebab}-{name}` (public-token convention).
+ */
+export interface MorfoCssVar {
+	/** Custom-property suffix; the full name is `--{kebab}-{name}`. */
+	name: string;
+	/** What the provider writes into it (documentation only). */
+	description?: string;
+}
+
 export interface Morfo {
 	/** Component display name, PascalCase. */
 	name: string;
@@ -898,6 +912,14 @@ export interface Morfo {
 	 * text slots*, not the localized content.
 	 */
 	texts?: Record<string, LangRef>;
+	/**
+	 * CSS custom properties the soma provider writes and the eidos recipe reads
+	 * (`--{kebab}-{name}`). Declaring them makes the soma→eidos functional-var
+	 * surface part of the contract: a guard verifies the provider writes each and
+	 * the recipe reads each, so renaming one side without the other fails loudly
+	 * instead of silently degrading to a fallback.
+	 */
+	cssVars?: readonly MorfoCssVar[];
 	/** The component's part tree. */
 	parts: readonly MorfoPart[];
 }