Preserve dotted literals in form value lookups

apps/web/app/(main)/docs/api/core/page.mdx

@@ -551,14 +551,19 @@ const name2 = resolveDynamicValue({ $state: "/user/name" }, state);  // "Alice"
 
 ### findFormValue
 
+Read a value from resolved action parameters or state. A parameter value is literal, including strings with dots such as emails, URLs, and versions. Lookup order: a defined direct parameter, a parameter key ending in `.<fieldName>`, a matching flat state key, then a slash-delimited path in nested state.
+
 ```typescript
 import { findFormValue } from '@json-render/core';
 
-// Find form values regardless of path format
-// Checks: params.name, params["form.name"], state["form.name"], state.form.name
-const value = findFormValue("name", params, state);
+findFormValue("email", { email: "john.doe@example.com" }, {});
+findFormValue("email", { "form.email": "john.doe@example.com" }, {});
+findFormValue("email", {}, { "form.email": "john.doe@example.com" });
+findFormValue("/form/email", {}, { form: { email: "john.doe@example.com" } });
 ```
 
+For action bindings, use `{ $state: "/form/email" }` to read nested state: the action resolver passes the resulting value to the handler. A raw string like `"form.email"` in parameters is not a state reference. A bare `"email"` field name does not search `state.form.email`.
+
 ## buildUserPrompt
 
 Build structured user prompts for AI generation, with support for refinement and state context.

packages/core/README.md

@@ -291,6 +291,8 @@ Schema options:
 | `ActionBinding` | Action binding with `action`, `params`, `confirm`, `preventDefault`, etc. |
 | `BuiltInAction` | Built-in action definition with `name` and `description` |
 
+Use `findFormValue("email", params, state)` in action handlers to look up a defined direct param, a dotted param key (such as `"form.email"`), a matching flat state key, or a slash path (such as `"/form/email"`) in nested state. Parameter values like `"john.doe@example.com"` are literal, even if they contain dots. To bind an action parameter to nested state, use `{ $state: "/form/email" }`; the action resolver supplies its value before the handler runs. A bare `"email"` field name does not recursively search nested state.
+
 ### Inline Mode (Mixed Streams)
 
 | Export | Purpose |

packages/core/src/actions.test.ts

@@ -7,6 +7,7 @@ import {
   ActionOnSuccessSchema,
   ActionOnErrorSchema,
 } from "./actions";
+import { findFormValue } from "./types";
 
 describe("onSuccess/onError schemas", () => {
   it("keeps params on the onSuccess action form", () => {
@@ -86,6 +87,21 @@ describe("resolveAction", () => {
     expect(resolved.params.theme).toBe("dark");
   });
 
+  it("passes a resolved dotted email to a form action handler", () => {
+    const state = { form: { email: "john.doe@example.com" } };
+    const resolved = resolveAction(
+      {
+        action: "createCustomer",
+        params: { email: { $state: "/form/email" } },
+      },
+      state,
+    );
+
+    expect(findFormValue("email", resolved.params, state)).toBe(
+      "john.doe@example.com",
+    );
+  });
+
   it("interpolates confirmation messages", () => {
     const data = { user: { name: "Alice" } };
     const resolved = resolveAction(

packages/core/src/types.test.ts

@@ -2,6 +2,7 @@ import { describe, it, expect } from "vitest";
 import {
   resolveDynamicValue,
   getByPath,
+  findFormValue,
   resolveRepeatStatePath,
   resolveRepeatItemStatePath,
   setByPath,
@@ -18,6 +19,109 @@ import {
 } from "./types";
 import type { Spec, SpecStreamLine, StreamChunk } from "./types";
 
+describe("findFormValue", () => {
+  const dottedValues = [
+    ["email", "john.doe@example.com"],
+    ["url", "https://example.com"],
+    ["version", "1.2.3"],
+  ];
+
+  it.each(dottedValues)("keeps a direct %s literal", (field, value) => {
+    expect(findFormValue(field, { [field]: value }, { [field]: "state" })).toBe(
+      value,
+    );
+  });
+
+  it.each(dottedValues)("keeps a dotted-key %s literal", (field, value) => {
+    expect(
+      findFormValue(
+        field,
+        { [`form.${field}`]: value },
+        { [`form.${field}`]: "state" },
+      ),
+    ).toBe(value);
+  });
+
+  it("treats a raw dotted parameter value as literal, even with matching state", () => {
+    expect(findFormValue("email", { email: "form.email" })).toBe("form.email");
+    expect(
+      findFormValue(
+        "email",
+        { email: "form.email" },
+        { "form.email": "state email" },
+      ),
+    ).toBe("form.email");
+  });
+
+  it("prefers a direct parameter over dotted parameters and state", () => {
+    expect(
+      findFormValue(
+        "email",
+        { email: "direct", "form.email": "dotted" },
+        { email: "state", "form.email": "dotted state" },
+      ),
+    ).toBe("direct");
+  });
+
+  it("prefers a dotted parameter over state and skips undefined direct params", () => {
+    expect(
+      findFormValue(
+        "email",
+        { email: undefined, "form.email": "dotted" },
+        { "form.email": "state" },
+      ),
+    ).toBe("dotted");
+  });
+
+  it("keeps the first matching dotted parameter key, even if undefined", () => {
+    expect(
+      findFormValue(
+        "email",
+        { "form.email": undefined, "other.email": "later" },
+        { email: "state" },
+      ),
+    ).toBeUndefined();
+  });
+
+  it("finds exact and dotted flat state keys", () => {
+    expect(findFormValue("email", undefined, { email: "exact" })).toBe("exact");
+    expect(
+      findFormValue("email", undefined, { "form.email": "dotted state" }),
+    ).toBe("dotted state");
+    expect(
+      findFormValue("email", undefined, {
+        email: "first",
+        "form.email": "second",
+      }),
+    ).toBe("first");
+  });
+
+  it("finds nested state with slash paths but not bare field names", () => {
+    const state = { form: { email: "nested@example.com" } };
+
+    expect(findFormValue("/form/email", undefined, state)).toBe(
+      "nested@example.com",
+    );
+    expect(findFormValue("form/email", undefined, state)).toBe(
+      "nested@example.com",
+    );
+    expect(findFormValue("email", undefined, state)).toBeUndefined();
+  });
+
+  it("ignores nonmatching keys and returns undefined for omitted inputs", () => {
+    expect(
+      findFormValue("email", { emailAddress: "other" }, {}),
+    ).toBeUndefined();
+    expect(findFormValue("email")).toBeUndefined();
+  });
+
+  it.each(["", 0, false, null])("preserves a direct %s value", (value) => {
+    expect(findFormValue("email", { email: value }, { email: "state" })).toBe(
+      value,
+    );
+  });
+});
+
 describe("getByPath", () => {
   it("gets nested values with JSON pointer paths", () => {
     const data = { user: { name: "John", scores: [10, 20, 30] } };

packages/core/src/types.ts

@@ -517,41 +517,35 @@ function deepEqual(a: unknown, b: unknown): boolean {
 /**
  * Find a form value from params and/or state.
  * Useful in action handlers to locate form input values regardless of path format.
+ * Params are literal values (including dynamic bindings resolved before the
+ * handler runs); a dot in a parameter value does not make it a state path.
  *
  * Checks in order:
- * 1. Direct param key (if not a path reference)
+ * 1. Defined direct param key
  * 2. Param keys ending with the field name
- * 3. State keys ending with the field name (dot notation)
- * 4. State path using getByPath (slash notation)
+ * 3. Matching flat state keys (direct or dot notation)
+ * 4. Nested state path using getByPath (slash notation)
  *
  * @example
  * // Find "name" from params or state
  * const name = findFormValue("name", params, state);
  *
- * // Will find from: params.name, params["form.name"], state["form.name"], or getByPath(state, "name")
+ * // Will find from: params.name, params["form.name"], or state["form.name"]
+ * // Use "/form/name" for nested state, or { $state: "/form/name" } in an action binding.
  */
 export function findFormValue(
   fieldName: string,
   params?: Record<string, unknown>,
   state?: Record<string, unknown>,
 ): unknown {
-  // Check params first (but not if it looks like a state path reference)
   if (params?.[fieldName] !== undefined) {
-    const val = params[fieldName];
-    // If the value looks like a path reference (contains dots), skip it
-    if (typeof val !== "string" || !val.includes(".")) {
-      return val;
-    }
+    return params[fieldName];
   }
 
-  // Check param keys that end with the field name
   if (params) {
     for (const key of Object.keys(params)) {
       if (key.endsWith(`.${fieldName}`)) {
-        const val = params[key];
-        if (typeof val !== "string" || !val.includes(".")) {
-          return val;
-        }
+        return params[key];
       }
     }
   }

skills/core/SKILL.md

@@ -96,6 +96,10 @@ const { result, newPatches } = compiler.push(chunk);
 const finalSpec = compiler.getResult();
 ```
 
+## Form Values in Action Handlers
+
+Use `findFormValue("email", params, state)` to read a direct parameter, a dotted parameter key (such as `"form.email"`), a matching flat state key, or a slash-delimited path (such as `"/form/email"`) in nested state. Parameter values are literal, so emails and URLs containing dots are preserved. For action bindings that read nested state, use `{ $state: "/form/email" }`; the resolver passes that value to the handler. A bare `"email"` field name does not search nested `state.form.email`.
+
 ## Dynamic Prop Expressions
 
 Any prop value can be a dynamic expression resolved at render time: