fix: resolve host-relative follow-up links against the origin, not baseUrl

src/low/followUpLinks.test.ts

@@ -0,0 +1,79 @@
+/**
+ * Follow-up links (`job.urls.*`) resolve against the origin, not baseUrl.
+ *
+ * A server mounts the v2 contract wherever it likes — the serverless gateway
+ * serves it under `/deployment/{id}/api/v2` — and its host-relative follow-up
+ * links already include that mount prefix. Resolving them against `baseUrl`
+ * (which carries the same prefix) doubles it and 404s; they must resolve
+ * against the scheme+authority only. Internal shorthand paths (`/jobs/…`,
+ * `/assets…`) keep resolving under `baseUrl` + `/api/v2`.
+ */
+
+import { describe, expect, it } from "vitest";
+
+import { ComfyLow } from "./transport.js";
+
+const GATEWAY_BASE = "https://stagingplatformapi.comfy.org/deployment/dep_123";
+
+function jobJson(id: string, urlsPrefix: string) {
+  return {
+    id,
+    status: "queued",
+    created_at: "2026-07-10T18:20:00Z",
+    started_at: null,
+    completed_at: null,
+    expires_at: "2026-07-11T18:20:00Z",
+    queue_position: 0,
+    progress: null,
+    outputs: [],
+    error: null,
+    metrics: null,
+    urls: {
+      self: `${urlsPrefix}/api/v2/jobs/${id}`,
+      events: `${urlsPrefix}/api/v2/jobs/${id}/events`,
+      cancel: `${urlsPrefix}/api/v2/jobs/${id}/cancel`,
+    },
+  };
+}
+
+function capturingLow(baseUrl: string, apiKey?: string) {
+  const requests: { url: string; auth: string | null }[] = [];
+  const fetchImpl = (async (input: RequestInfo | URL, init?: RequestInit) => {
+    const url = input instanceof Request ? input.url : String(input);
+    const headers = new Headers(input instanceof Request ? input.headers : init?.headers);
+    requests.push({ url, auth: headers.get("Authorization") });
+    return new Response(JSON.stringify(jobJson("j1", "/deployment/dep_123")), {
+      status: 200,
+      headers: { "Content-Type": "application/json" },
+    });
+  }) as typeof fetch;
+  return { low: new ComfyLow(baseUrl, apiKey, { fetch: fetchImpl }), requests };
+}
+
+describe("follow-up link resolution", () => {
+  it("resolves a gateway self link against the origin, not baseUrl", async () => {
+    const { low, requests } = capturingLow(GATEWAY_BASE, "comfyui-k");
+    await low.getJob("/deployment/dep_123/api/v2/jobs/j1");
+    expect(requests[0].url).toBe(
+      "https://stagingplatformapi.comfy.org/deployment/dep_123/api/v2/jobs/j1",
+    );
+  });
+
+  it("keeps the deployment prefix for internal shorthand paths", async () => {
+    const { low, requests } = capturingLow(GATEWAY_BASE, "comfyui-k");
+    await low.getJob("j1");
+    expect(requests[0].url).toBe(`${GATEWAY_BASE}/api/v2/jobs/j1`);
+  });
+
+  it("leaves bare-surface self links unchanged", async () => {
+    const { low, requests } = capturingLow("https://api.comfy.org", "comfyui-k");
+    await low.getJob("/api/v2/jobs/j1");
+    expect(requests[0].url).toBe("https://api.comfy.org/api/v2/jobs/j1");
+  });
+
+  it("still attaches auth to origin-resolved links", async () => {
+    const { low, requests } = capturingLow(GATEWAY_BASE, "comfyui-k");
+    await low.getJob("/deployment/dep_123/api/v2/jobs/j1");
+    expect(requests[0].auth).toBe("Bearer comfyui-k");
+  });
+});

src/low/transport.ts

@@ -142,7 +142,16 @@ export class ComfyLow {
 
   private urlFor(path: string): string {
     if (path.startsWith("http")) return path;
-    if (path.startsWith("/api/")) return this.baseUrl + path;
+    // A server link (job.urls.*, marked by containing /api/) already carries
+    // the server's mount prefix, so it resolves against the origin — joining
+    // it to baseUrl would double the prefix on a prefix-mounted surface.
+    if (path.startsWith("/") && path.includes("/api/")) {
+      try {
+        return new URL(this.baseUrl).origin + path;
+      } catch {
+        return this.baseUrl + path;
+      }
+    }
     return this.baseUrl + API_PREFIX + path;
   }