diff --git a/src/daemon/http/index.ts b/src/daemon/http/index.ts
index 8979aa7..8bfb8ce 100644
--- a/src/daemon/http/index.ts
+++ b/src/daemon/http/index.ts
@@ -22,6 +22,7 @@ import { receiveCashuToken } from "../wallet";
 import { getClientsFromStore } from "../../utils/clients";
 import { getUsageSummary } from "./usage-summary";
 import { applyDefaultOutputTokenLimit } from "./request-body";
+import { collapseDuplicatedV1 } from "./request-path";
 import {
   buildCooldownsOutput,
   type StoredCooldownEntry,
@@ -447,6 +448,19 @@ export function createDaemonRequestHandler(deps: {
     const host = req.headers.host || "localhost";
     const url = new URL(req.url || "/", `http://${host}`);
 
+    // The node canonicalizes exactly ONE optional "v1/" segment (routstr-core
+    // `_canonical_api_path`). A client whose base URL already ends in /v1 while
+    // its transport appends /v1 itself — the Anthropic SDKs do, the OpenAI ones
+    // do not — would otherwise get a paid upstream 404 from every provider in
+    // the pool. Collapse the duplicate before any routing or payment decision.
+    const canonicalPath = collapseDuplicatedV1(url.pathname);
+    if (canonicalPath !== url.pathname) {
+      logger.warn(
+        `[daemon] Collapsing duplicated '/v1' in request path: ${url.pathname} -> ${canonicalPath}`,
+      );
+      url.pathname = canonicalPath;
+    }
+
     if (req.method === "GET" && url.pathname === "/health") {
       sendJson(res, 200, { ok: true });
       return;
diff --git a/src/daemon/http/request-path.test.ts b/src/daemon/http/request-path.test.ts
new file mode 100644
index 0000000..a2759c3
--- /dev/null
+++ b/src/daemon/http/request-path.test.ts
@@ -0,0 +1,42 @@
+import { describe, expect, it } from "bun:test";
+import { collapseDuplicatedV1 } from "./request-path";
+
+describe("collapseDuplicatedV1", () => {
+  it("collapses the doubled prefix an Anthropic-style client produces", () => {
+    // base URL ends in /v1 and the Anthropic SDK appends /v1/messages itself
+    expect(collapseDuplicatedV1("/v1/v1/messages")).toBe("/v1/messages");
+    expect(collapseDuplicatedV1("/v1/v1/messages/count_tokens")).toBe(
+      "/v1/messages/count_tokens",
+    );
+    expect(collapseDuplicatedV1("/v1/v1/chat/completions")).toBe("/v1/chat/completions");
+  });
+
+  it("collapses every repetition, including a bare or trailing-slash path", () => {
+    expect(collapseDuplicatedV1("/v1/v1/v1/messages")).toBe("/v1/messages");
+    expect(collapseDuplicatedV1("/v1/v1")).toBe("/v1");
+    expect(collapseDuplicatedV1("/v1/v1/")).toBe("/v1/");
+  });
+
+  it("leaves canonical and unprefixed paths untouched", () => {
+    for (const path of [
+      "/v1/messages",
+      "/v1/chat/completions",
+      "/v1/responses",
+      "/v1/systemone",
+      "/chat/completions",
+      "/responses",
+      "/v1/models",
+      "/v1/v1x/messages",
+      "/v1/v2/v1/messages",
+      "/health",
+      "/",
+    ]) {
+      expect(collapseDuplicatedV1(path)).toBe(path);
+    }
+  });
+
+  it("is idempotent", () => {
+    const once = collapseDuplicatedV1("/v1/v1/v1/messages");
+    expect(collapseDuplicatedV1(once)).toBe(once);
+  });
+});
diff --git a/src/daemon/http/request-path.ts b/src/daemon/http/request-path.ts
new file mode 100644
index 0000000..be7a759
--- /dev/null
+++ b/src/daemon/http/request-path.ts
@@ -0,0 +1,39 @@
+/**
+ * Request-path canonicalization for the proxied path.
+ *
+ * routstr-core reduces an incoming path to its allowlist key by stripping
+ * exactly ONE optional leading `v1/` segment (`_canonical_api_path` in
+ * `routstr/proxy.py`), then requires an exact match against its endpoint
+ * table. Both `/chat/completions` and `/v1/chat/completions` therefore reach
+ * the same handler, and no spelling with the prefix repeated ever does:
+ * `/v1/v1/messages` canonicalizes to `v1/messages`, which is not an endpoint,
+ * so the node answers `404 Path '/v1/v1/messages' not found`.
+ *
+ * That second prefix is not hypothetical — it is what an Anthropic-style
+ * client produces when its base URL already ends in `/v1`, because the
+ * Anthropic SDKs append `/v1/messages` themselves (the OpenAI SDKs append only
+ * `/chat/completions` and leave the prefix to the configured base URL). One
+ * such client turns every request into a paid upstream 404 on every provider in
+ * the pool, so collapse the duplicate here, before any routing or payment
+ * decision.
+ */
+
+/**
+ * Collapse a repeated leading `/v1` segment to a single one.
+ *
+ * `/v1/v1/messages` and `/v1/v1/v1/messages` both become `/v1/messages`;
+ * `/v1/messages`, `/chat/completions`, and every other spelling are returned
+ * unchanged. Only the repeated `v1` segment is touched: the node owns the
+ * endpoint allowlist, and rewriting anything else here would make this
+ * ingress answer for paths it knows nothing about.
+ *
+ * Never throws and is idempotent: each pass shortens the path, so a path
+ * that does not start with a doubled `/v1` is returned as-is.
+ */
+export function collapseDuplicatedV1(pathname: string): string {
+  let path = pathname;
+  while (path.startsWith("/v1/v1/") || path === "/v1/v1") {
+    path = path.slice(3);
+  }
+  return path;
+}