Use Effect fn for Ollama embeddings

ts/EFFECT_NATIVE_REWRITE_AUDIT.md

@@ -2143,6 +2143,27 @@ Notes:
   - `cd ts && bun run lint`
   - `git diff --check`
 
+### 2026-06-04: Ollama Embeddings Effect.fn Helper Slice
+
+- Status: migrated and package-verified.
+- Completed:
+  - `ts/packages/flow/src/embeddings/ollama.ts` now defines the `embed`
+    service method as a named `Effect.fn` generator instead of returning a
+    nested `Effect.gen` from an `Effect.fn` callback.
+  - Empty embedding requests now return through the same generator path without
+    allocating a separate `Effect.succeed` helper.
+  - The public sync factory, effectful layer, `ManagedRuntime` facade, and
+    `NodeRuntime.runMain` entrypoint are unchanged.
+  - The focused scan for Ollama `return Effect.gen(...)` helper patterns is
+    clean.
+- Verification:
+  - `cd ts/packages/flow && bunx --bun vitest run src/__tests__/ollama-embeddings.test.ts`
+  - `cd ts && bun run check:tsgo`
+  - `cd ts && bun run build`
+  - `cd ts && bun run test`
+  - `cd ts && bun run lint`
+  - `git diff --check`
+
 ## Subagent Findings To Preserve
 
 - MCP/workbench:
@@ -2301,9 +2322,8 @@ Notes:
   - Fresh strict signal sweep after the 2026-06-04 helper and collection
     slices found no production normal `Error`, raw `try`/`catch`, native
     `switch`, or Effect-focused type assertions under `ts/packages`.
-  - Remaining real helper-normalization targets from the fresh sweep are
-    embeddings/ollama, base processor flow helpers, and one workbench atom
-    helper.
+  - Remaining real helper-normalization targets from the fresh sweep are base
+    processor flow helpers and one workbench atom helper.
   - Remaining real long-lived native collection targets include base processor
     registries, Librarian service / collection manager state, prompt template
     cache, and a workbench module cache. Local traversal sets and test fakes

ts/packages/flow/src/embeddings/ollama.ts

@@ -79,52 +79,50 @@ const makeOllamaEmbeddingsFromConfig = ({
   ollamaHost,
   fetchImpl,
 }: ResolvedOllamaEmbeddingsConfig): EmbeddingsServiceShape => ({
-    embed: Effect.fn("OllamaEmbeddings.embed")((texts: ReadonlyArray<string>, model?: string) => {
+    embed: Effect.fn("OllamaEmbeddings.embed")(function* (texts: ReadonlyArray<string>, model?: string) {
       if (texts.length === 0) {
-        return Effect.succeed([]);
+        return [];
       }
 
       const useModel = model ?? defaultModel;
       const url = `${ollamaHost}/api/embed`;
 
-      return Effect.gen(function* () {
-        const body = yield* S.encodeUnknownEffect(S.UnknownFromJsonString)({
-          model: useModel,
-          input: Array.from(texts),
-        }).pipe(
-          Effect.mapError((error) => ollamaEmbeddingsError("ollama.encode-request", error))
-        );
+      const body = yield* S.encodeUnknownEffect(S.UnknownFromJsonString)({
+        model: useModel,
+        input: Array.from(texts),
+      }).pipe(
+        Effect.mapError((error) => ollamaEmbeddingsError("ollama.encode-request", error))
+      );
 
-        const response = yield* Effect.tryPromise({
-          try: () =>
-            fetchImpl(url, {
-              method: "POST",
-              headers: { "Content-Type": "application/json" },
-              body,
-            }),
-          catch: (error) => ollamaEmbeddingsError("ollama.fetch", error),
-        });
-
-        if (!response.ok) {
-          const errorBody = yield* Effect.tryPromise({
-            try: () => response.text(),
-            catch: (error) => ollamaEmbeddingsError("ollama.error-body", error),
-          });
-          return yield* ollamaEmbeddingsMessageError(
-            "ollama.embed",
-            `Ollama embeddings request failed (${response.status}): ${errorBody}`,
-          );
-        }
-
-        const data = yield* Effect.tryPromise({
-          try: () => responseJson(response),
-          catch: (error) => ollamaEmbeddingsError("ollama.response-json", error),
-        });
-        const decoded = yield* S.decodeUnknownEffect(OllamaEmbedResponse)(data).pipe(
-          Effect.mapError((error) => ollamaEmbeddingsError("ollama.decode-response", error))
-        );
-        return Array.from(decoded.embeddings, (vector) => Array.from(vector));
+      const response = yield* Effect.tryPromise({
+        try: () =>
+          fetchImpl(url, {
+            method: "POST",
+            headers: { "Content-Type": "application/json" },
+            body,
+          }),
+        catch: (error) => ollamaEmbeddingsError("ollama.fetch", error),
       });
+
+      if (!response.ok) {
+        const errorBody = yield* Effect.tryPromise({
+          try: () => response.text(),
+          catch: (error) => ollamaEmbeddingsError("ollama.error-body", error),
+        });
+        return yield* ollamaEmbeddingsMessageError(
+          "ollama.embed",
+          `Ollama embeddings request failed (${response.status}): ${errorBody}`,
+        );
+      }
+
+      const data = yield* Effect.tryPromise({
+        try: () => responseJson(response),
+        catch: (error) => ollamaEmbeddingsError("ollama.response-json", error),
+      });
+      const decoded = yield* S.decodeUnknownEffect(OllamaEmbedResponse)(data).pipe(
+        Effect.mapError((error) => ollamaEmbeddingsError("ollama.decode-response", error))
+      );
+      return Array.from(decoded.embeddings, (vector) => Array.from(vector));
     }),
   });