diff --git a/skills/rig/rig.ts b/skills/rig/rig.ts
index 708bf6f..6ecb243 100644
--- a/skills/rig/rig.ts
+++ b/skills/rig/rig.ts
@@ -30,7 +30,7 @@
  * T:JsonSchemaObject type {[key:string]:unknown} plain JSON Schema object
  * s.string/number/integer/boolean/null SchemaHelperFactory primitives; call as value or fn(desc)
  * s.int alias for s.integer; s.nonEmptyString string with minLength:1; s.url string with format:"uri"; s.path string with format:"path"; s.date string with format:"date" validated as YYYY-MM-DD
- * s.positiveInt integer with minimum:1; s.nonNegativeInt integer with minimum:0; NumberSchema/IntegerSchema support minimum/maximum constraints
+ * s.positiveInt integer with minimum:1; s.nonNegativeInt integer with minimum:0; s.percent number with minimum:0,maximum:100; NumberSchema/IntegerSchema support minimum/maximum constraints
  * s.array(items,desc?) ArraySchema; use for homogeneous lists, e.g. s.array(s.string)
  * s.nonEmptyArray(items,desc?) ArraySchema with minItems:1; validates array has at least one element
  * s.object(props,desc?) ObjectSchema; s.optional(inner) marks field optional; s.nullable(inner) accepts inner|null; use for fixed-key shapes
@@ -253,6 +253,8 @@ export const s = {
   positiveInt: createConstrainedNumberSchema<IntegerSchema>({ type: "integer", minimum: 1 }),
   /** Schema for a non-negative integer (minimum: 0). Call as `s.nonNegativeInt` or `s.nonNegativeInt("description")`. */
   nonNegativeInt: createConstrainedNumberSchema<IntegerSchema>({ type: "integer", minimum: 0 }),
+  /** Schema for a percentage value (number in the range 0–100, inclusive). Use instead of `s.number` when the value is a percentage; validates that the number is between 0 and 100. Call as `s.percent` or `s.percent("description")`. */
+  percent: createConstrainedNumberSchema<NumberSchema>({ type: "number", minimum: 0, maximum: 100 }),
   /** Schema for a `boolean` value. Call as `s.boolean` or `s.boolean("description")`. */
   boolean: createTypedPrimitiveSchema<BooleanSchema>("boolean"),
   /** Schema for the JSON `null` literal. Call as `s.null` or `s.null("description")`. */
diff --git a/src/rig.test.ts b/src/rig.test.ts
index aecf2d3..e824d5b 100644
--- a/src/rig.test.ts
+++ b/src/rig.test.ts
@@ -1536,6 +1536,26 @@ describe("s.nonNegativeInt", () => {
   });
 });
 
+describe("s.percent", () => {
+  it("serializes to {type:'number', minimum:0, maximum:100}", () => {
+    expect(toJsonSchema(s.percent)).toEqual({ type: "number", minimum: 0, maximum: 100 });
+    expect(toJsonSchema(s.percent("coverage percentage"))).toEqual({ type: "number", minimum: 0, maximum: 100, description: "coverage percentage" });
+  });
+
+  it("accepts numbers in range [0, 100]", () => {
+    expect(analyzeResponse(JSON.stringify(0), s.percent, "test", 1).ok).toBe(true);
+    expect(analyzeResponse(JSON.stringify(50.5), s.percent, "test", 1).ok).toBe(true);
+    expect(analyzeResponse(JSON.stringify(100), s.percent, "test", 1).ok).toBe(true);
+  });
+
+  it("rejects numbers outside [0, 100]", () => {
+    const below = analyzeResponse(JSON.stringify(-1), s.percent, "test", 1);
+    expect(below.ok).toBe(false);
+    const above = analyzeResponse(JSON.stringify(101), s.percent, "test", 1);
+    expect(above.ok).toBe(false);
+  });
+});
+
 describe("NumberSchema and IntegerSchema minimum/maximum", () => {
   it("serializes minimum and maximum on number schema", () => {
     const schema: import("rig").NumberSchema = { type: "number", minimum: 0, maximum: 1 };