diff --git a/packages/coding-agent/test/extensibility/typebox-shim.test.ts b/packages/coding-agent/test/extensibility/typebox-shim.test.ts
index 1ad333392..7eb792225 100644
--- a/packages/coding-agent/test/extensibility/typebox-shim.test.ts
+++ b/packages/coding-agent/test/extensibility/typebox-shim.test.ts
@@ -280,6 +280,31 @@ describe("pi.typebox compatibility shim", () => {
 			expect(schema.safeParse(true).success).toBe(false);
 		});
 
+		it("preserves wire-only constraints on embedded schema builders", () => {
+			const schema = Type.Unsafe({
+				type: "object",
+				properties: {
+					code: Type.String({ pattern: "^x" }),
+					count: Type.Number({ multipleOf: 2 }),
+				},
+				required: ["code", "count"],
+				additionalProperties: false,
+			});
+
+			expect(schema.toJsonSchema()).toEqual({
+				type: "object",
+				properties: {
+					code: { type: "string", pattern: "^x" },
+					count: { type: "number", multipleOf: 2 },
+				},
+				required: ["code", "count"],
+				additionalProperties: false,
+			});
+			expect(schema.safeParse({ code: "xray", count: 4 }).success).toBe(true);
+			expect(schema.safeParse({ code: "bad", count: 4 }).success).toBe(false);
+			expect(schema.safeParse({ code: "xray", count: 3 }).success).toBe(false);
+		});
+
 		it("recovers the wire schema when a builder is spread into a new document", () => {
 			const base = Type.Unsafe({
 				anyOf: [
diff --git a/packages/omptype/CHANGELOG.md b/packages/omptype/CHANGELOG.md
index 37c104eec..d3e1d0c6f 100644
--- a/packages/omptype/CHANGELOG.md
+++ b/packages/omptype/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed the TypeBox adapter omitting `pattern`, non-URL `format`, and `multipleOf` from emitted JSON Schema even though runtime validation enforced them ([#8425](https://github.com/can1357/oh-my-pi/pull/8425)).
+
 ## [17.3.0] - 2026-08-13
 
 ### Added
diff --git a/packages/omptype/src/typebox.ts b/packages/omptype/src/typebox.ts
index 7e252a556..b674d47d6 100644
--- a/packages/omptype/src/typebox.ts
+++ b/packages/omptype/src/typebox.ts
@@ -220,7 +220,11 @@ function tString(opts?: StringOpts): TString {
 		const valid = formatPredicate(format);
 		schema = schema.narrow((value, ctx) => valid(value) || ctx.mustBe(`a string in ${format} format`));
 	}
-	return applyMeta(schema, opts);
+	const result = applyMeta(schema, opts);
+	const keywords: Record<string, unknown> = {};
+	if (opts?.pattern !== undefined) keywords.pattern = opts.pattern;
+	if (opts?.format !== undefined) keywords.format = opts.format === "url" ? "uri" : opts.format;
+	return opts?.pattern !== undefined || opts?.format !== undefined ? withJsonSchemaKeywords(result, keywords) : result;
 }
 
 function formatPredicate(format: string): (value: string) => boolean {
@@ -290,7 +294,8 @@ function tNumber(opts?: NumberOpts, integer = false): TNumber {
 			);
 		});
 	}
-	return applyMeta(schema, opts);
+	const result = applyMeta(schema, opts);
+	return opts?.multipleOf !== undefined ? withJsonSchemaKeywords(result, { multipleOf: opts.multipleOf }) : result;
 }
 
 function tLiteral<const V extends string | number | boolean | null>(value: V, opts?: Meta): TLiteral<V> {
diff --git a/packages/omptype/test/typebox.test.ts b/packages/omptype/test/typebox.test.ts
index 0ded2d33f..24cfb5a78 100644
--- a/packages/omptype/test/typebox.test.ts
+++ b/packages/omptype/test/typebox.test.ts
@@ -46,11 +46,17 @@ describe("TypeBox adapter", () => {
 		expect(valid(Type.String({ format: "email" }), "a@b.co")).toBe(true);
 		expect(valid(Type.String({ format: "email" }), "nope")).toBe(false);
 		expect(Type.String({ format: "url" }).toJsonSchema()).toEqual({ type: "string", format: "uri" });
+		expect(Type.String({ pattern: "^[a-z]+$", format: "email" }).toJsonSchema()).toEqual({
+			type: "string",
+			pattern: "^[a-z]+$",
+			format: "email",
+		});
 
 		const number = Type.Number({ minimum: 1, maximum: 10, multipleOf: 2 });
 		expect(valid(number, 4)).toBe(true);
 		expect(valid(number, 0)).toBe(false);
 		expect(valid(number, 3)).toBe(false);
+		expect(number.toJsonSchema()).toEqual({ type: "number", minimum: 1, maximum: 10, multipleOf: 2 });
 		const exclusive = Type.Number({ exclusiveMinimum: 1, exclusiveMaximum: 3 });
 		expect(valid(exclusive, 2)).toBe(true);
 		expect(valid(exclusive, 1)).toBe(false);