4 files changed, 86 insertions, 0 deletions
diff --git a/source/library/fetcher/http.ts b/source/library/fetcher/http.ts
new file mode 100644
index 0000000..3138226
--- /dev/null
+++ b/source/library/fetcher/http.ts
@@ -0,0 +1,30 @@
+
+
+
+/*** UTILITY ------------------------------------------ ***/
+
+import type { Fetcher, FetcherOptions } from "./types.ts";
+
+/*** EXPORT ------------------------------------------- ***/
+
+export function createHttpFetcher(options: FetcherOptions): Fetcher {
+  const fetchImpl = options.fetch ?? globalThis.fetch;
+
+  return async (req) => {
+    const response = await fetchImpl(options.url, {
+      body: JSON.stringify({
+        operationName: req.operationName,
+        query: req.query,
+        variables: req.variables
+      }),
+      headers: {
+        "Content-Type": "application/json",
+        ...options.headers,
+        ...req.headers
+      },
+      method: "POST"
+    });
+
+    return await response.json();
+  };
+}
diff --git a/source/library/fetcher/sse.ts b/source/library/fetcher/sse.ts
new file mode 100644
index 0000000..b6805dc
--- /dev/null
+++ b/source/library/fetcher/sse.ts
@@ -0,0 +1,18 @@
+
+
+
+/*** UTILITY ------------------------------------------ ***/
+
+import type { Fetcher, FetcherOptions } from "./types.ts";
+
+/*** EXPORT ------------------------------------------- ***/
+
+/**
+ * Server-Sent Events fetcher for graphql-sse protocol.
+ * Stub implementation — see PLAN.md stage v0.4 for full implementation.
+ */
+export function createSseFetcher(_options: FetcherOptions): Fetcher {
+  return () => {
+    throw new Error("SSE fetcher not yet implemented — see PLAN.md v0.4");
+  };
+}
diff --git a/source/library/fetcher/types.ts b/source/library/fetcher/types.ts
new file mode 100644
index 0000000..af849a9
--- /dev/null
+++ b/source/library/fetcher/types.ts
@@ -0,0 +1,20 @@
+
+
+
+/*** EXPORT ------------------------------------------- ***/
+
+export type FetcherRequest = {
+  headers?: Record<string, string>;
+  operationName?: string | null;
+  query: string;
+  variables?: Record<string, unknown>;
+};
+
+export type FetcherResult = Record<string, unknown>;
+export type Fetcher = (req: FetcherRequest) => Promise<FetcherResult> | AsyncIterable<FetcherResult>;
+
+export type FetcherOptions = {
+  fetch?: typeof globalThis.fetch;
+  headers?: Record<string, string>;
+  url: string;
+};
diff --git a/source/library/fetcher/websocket.ts b/source/library/fetcher/websocket.ts
new file mode 100644
index 0000000..6376e76
--- /dev/null
+++ b/source/library/fetcher/websocket.ts
@@ -0,0 +1,18 @@
+
+
+
+/*** UTILITY ------------------------------------------ ***/
+
+import type { Fetcher, FetcherOptions } from "./types.ts";
+
+/*** EXPORT ------------------------------------------- ***/
+
+/**
+ * WebSocket fetcher for graphql-ws protocol.
+ * Stub implementation — see PLAN.md stage v0.4 for full implementation.
+ */
+export function createWsFetcher(_options: FetcherOptions): Fetcher {
+  return () => {
+    throw new Error("WebSocket fetcher not yet implemented — see PLAN.md v0.4");
+  };
+}