diff --git a/packages/adapters/src/comfyui-provider.ts b/packages/adapters/src/comfyui-provider.ts
index ec35de7..e2410a1 100644
--- a/packages/adapters/src/comfyui-provider.ts
+++ b/packages/adapters/src/comfyui-provider.ts
@@ -75,6 +75,7 @@ export interface ComfyUiProvider extends ImageGenerationProvider, VideoGeneratio
 }
 
 type MediaKind = "image" | "video";
+type ReadBody<T> = (response: Response, signal: AbortSignal) => Promise<T>;
 
 interface OutputFile {
   filename: string;
@@ -259,20 +260,18 @@ class ComfyUiClient implements ComfyUiProvider {
   }
 
   private async submit(graph: ComfyWorkflow, signal: AbortSignal): Promise<string> {
-    const body = JSON.stringify({ prompt: graph, client_id: this.clientId });
-    return this.send("prompt", { method: "POST", headers: JSON_HEADERS, body }, signal, {
-      read: async (response, readSignal) => {
-        if (response.status === 400) {
-          const rejection = await readJson(response, readSignal).catch(() => undefined);
-          throw new Error(describeWorkflowRejection(rejection));
-        }
-        const result = await readOkJson(response, readSignal);
-        const promptId = isRecord(result) ? result.prompt_id : undefined;
-        if (typeof promptId !== "string" || !promptId) {
-          throw new Error("ComfyUI did not accept the workflow");
-        }
-        return promptId;
-      },
+    const payload = { prompt: graph, client_id: this.clientId };
+    return this.postJson("prompt", payload, signal, async (response, readSignal) => {
+      if (response.status === 400) {
+        const rejection = await readJson(response, readSignal).catch(() => undefined);
+        throw new Error(describeWorkflowRejection(rejection));
+      }
+      const result = await readOkJson(response, readSignal);
+      const promptId = isRecord(result) ? result.prompt_id : undefined;
+      if (typeof promptId !== "string" || !promptId) {
+        throw new Error("ComfyUI did not accept the workflow");
+      }
+      return promptId;
     });
   }
 
@@ -291,29 +290,20 @@ class ComfyUiClient implements ComfyUiProvider {
 
   /** Best effort: drops the prompt from the queue, or interrupts it when it is ours and running. */
   private async cancelPrompt(promptId: string): Promise<void> {
-    const options = { timeoutMs: CANCEL_TIMEOUT_MS, read: discardBody };
     try {
-      const body = JSON.stringify({ delete: [promptId] });
-      await this.send("queue", { method: "POST", headers: JSON_HEADERS, body }, undefined, options);
-      const queue = await this.send(
+      await this.postJson(
         "queue",
-        { headers: { Accept: "application/json" } },
+        { delete: [promptId] },
         undefined,
-        {
-          timeoutMs: CANCEL_TIMEOUT_MS,
-          read: readOkJson,
-        },
+        discardBody,
+        CANCEL_TIMEOUT_MS,
       );
+      const queue = await this.getJson("queue", undefined, CANCEL_TIMEOUT_MS);
       const running =
         isRecord(queue) && Array.isArray(queue.queue_running) ? queue.queue_running : [];
       if (running.some((entry) => Array.isArray(entry) && entry[1] === promptId)) {
-        const interrupt = JSON.stringify({ prompt_id: promptId });
-        await this.send(
-          "interrupt",
-          { method: "POST", headers: JSON_HEADERS, body: interrupt },
-          undefined,
-          options,
-        );
+        const interrupt = { prompt_id: promptId };
+        await this.postJson("interrupt", interrupt, undefined, discardBody, CANCEL_TIMEOUT_MS);
       }
     } catch {
       // The prompt then finishes on its own; nothing waits for it.
@@ -379,10 +369,20 @@ class ComfyUiClient implements ComfyUiProvider {
     });
   }
 
-  private getJson(path: string, signal: AbortSignal | undefined): Promise<unknown> {
-    return this.send(path, { headers: { Accept: "application/json" } }, signal, {
-      read: readOkJson,
-    });
+  private getJson(path: string, signal: AbortSignal | undefined, timeoutMs?: number) {
+    const init = { headers: { Accept: "application/json" } };
+    return this.send(path, init, signal, { timeoutMs, read: readOkJson });
+  }
+
+  private postJson<T>(
+    path: string,
+    payload: unknown,
+    signal: AbortSignal | undefined,
+    read: ReadBody<T>,
+    timeoutMs?: number,
+  ): Promise<T> {
+    const init = { method: "POST", headers: JSON_HEADERS, body: JSON.stringify(payload) };
+    return this.send(path, init, signal, { timeoutMs, read });
   }
 
   /** One request, with the timeout covering the response body too. */
@@ -394,10 +394,7 @@ class ComfyUiClient implements ComfyUiProvider {
       body?: string | Uint8Array<ArrayBuffer>;
     },
     signal: AbortSignal | undefined,
-    options: {
-      timeoutMs?: number;
-      read: (response: Response, signal: AbortSignal) => Promise<T>;
-    },
+    options: { timeoutMs?: number; read: ReadBody<T> },
   ): Promise<T> {
     const timeout = AbortSignal.timeout(options.timeoutMs ?? REQUEST_TIMEOUT_MS);
     const requestSignal = signal ? AbortSignal.any([signal, timeout]) : timeout;