From 510d430e01fa7886910c79147d021ca90eedc640 Mon Sep 17 00:00:00 2001
From: Farrel Darian <62016900+fdarian@users.noreply.github.com>
Date: Sat, 4 Apr 2026 16:18:22 +0700
Subject: [PATCH 1/2] fix: preserve OUTPUT generic in generateText wrapper

Thread TOOLS and OUTPUT type parameters through so the return type reflects
the actual output schema instead of resolving to `any`.
---
 packages/effect/src/for/ai/index.ts | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/packages/effect/src/for/ai/index.ts b/packages/effect/src/for/ai/index.ts
index 91cb99d..c515ac3 100644
--- a/packages/effect/src/for/ai/index.ts
+++ b/packages/effect/src/for/ai/index.ts
@@ -42,16 +42,21 @@ type EffectifyCallbacks<T, Keys extends string, R> = Omit<T, Keys & keyof T> & {
 		: T[K];
 };
 
-type GenerateTextOriginalParams = Parameters<typeof Ai.generateText>[0];
-type GenerateTextReturn = Awaited<ReturnType<typeof Ai.generateText>>;
-
-export function generateText<R = never>(
+export function generateText<
+	TOOLS extends Ai.ToolSet = Ai.ToolSet,
+	OUTPUT extends Ai.Output.Output = Ai.Output.Output<string, string>,
+	R = never,
+>(
 	params: EffectifyCallbacks<
-		GenerateTextOriginalParams,
+		Parameters<typeof Ai.generateText<TOOLS, OUTPUT>>[0],
 		GenerateTextCallbackKeys,
 		R
 	>,
-): Effect.Effect<GenerateTextReturn, AiError, R> {
+): Effect.Effect<
+	Awaited<ReturnType<typeof Ai.generateText<TOOLS, OUTPUT>>>,
+	AiError,
+	R
+> {
 	return Effect.gen(function* () {
 		const runPromise = yield* FiberSet.makeRuntimePromise<R>();
 
@@ -75,7 +80,7 @@ export function generateText<R = never>(
 				runPromise,
 				params.experimental_onToolCallFinish,
 			),
-		} as GenerateTextOriginalParams;
+		} as Parameters<typeof Ai.generateText<TOOLS, OUTPUT>>[0];
 
 		return yield* Effect.tryPromise({
 			try: () => Ai.generateText(originalParams),

From 8498ce9bf6d1169fb11dcca735e4d657f26fc22c Mon Sep 17 00:00:00 2001
From: Farrel Darian <62016900+fdarian@users.noreply.github.com>
Date: Sat, 4 Apr 2026 16:18:53 +0700
Subject: [PATCH 2/2] docs: changeset

---
 .changeset/generate-text-output-type.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/generate-text-output-type.md

diff --git a/.changeset/generate-text-output-type.md b/.changeset/generate-text-output-type.md
new file mode 100644
index 0000000..3e80cce
--- /dev/null
+++ b/.changeset/generate-text-output-type.md
@@ -0,0 +1,5 @@
+---
+"ff-effect": patch
+---
+
+fix: preserve `OUTPUT` generic in `generateText` wrapper so `result.output` is properly typed instead of resolving to `any`