fix(hooks): pass user-configured policyParams to custom policies (#585)

__tests__/hooks/policy-evaluator.test.ts

@@ -1218,5 +1218,23 @@ describe("hooks/policy-evaluator", () => {
       expect(result.decision).toBe("deny");
       expect(result.reason).toBe("hard block. deny hint");
     });
+
+    it("passes user-configured policyParams to custom policies without schema", async () => {
+      let capturedParams: unknown = null;
+      registerPolicy("custom/my-policy", "desc", (ctx) => {
+        capturedParams = ctx.params;
+        return { decision: "allow" };
+      }, { events: ["PreToolUse"] });
+
+      const config = {
+        enabledPolicies: ["custom/my-policy"],
+        policyParams: {
+          "custom/my-policy": { maxCount: 10, threshold: 5 },
+        },
+      };
+
+      await evaluatePolicies("PreToolUse", { tool_name: "Bash" }, undefined, config);
+      expect(capturedParams).toEqual({ maxCount: 10, threshold: 5 });
+    });
   });
 });

src/hooks/policy-evaluator.ts

@@ -101,8 +101,9 @@ export async function evaluatePolicies(
       }
       ctx = { ...baseCtx, params: resolvedParams };
     } else {
-      // Custom hooks and policies without schema get empty params
-      ctx = { ...baseCtx, params: {} };
+      // Custom hooks and policies without schema get user-configured params if present
+      const userParams = getConfigParamsFor(config, policy.name) ?? {};
+      ctx = { ...baseCtx, params: userParams };
     }
 
     let result: Awaited<ReturnType<typeof policy.fn>>;