fix(executors): inject reasoning_content for native Kimi provider (port from 9router#1480) (#6419)

inject reasoning_content for native Kimi (port #1480) (net +1/-0, test OK). Integrated into release/v3.8.46.

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 ### 🐛 Bug Fixes
 
+- **fix(executors):** inject the `reasoning_content` echo for the native **Moonshot Kimi** provider. Kimi (executor `default`) is a thinking-mode upstream that 400s with "reasoning_content must be passed back" when a prior assistant turn lacks it; the placeholder injection was only wired into the OpenCode meta-provider, so direct multi-turn Kimi conversations failed. Scoped to `kimi` (gateway-served models matching the thinking-model name pattern are unaffected). Regression guard: `tests/unit/kimi-native-reasoning-injected-1480.test.ts`. (thanks @2220258345)
 - **fix(executors):** recover from a strict gateway's `context_management: Extra inputs are not permitted` 400. **Claude Code** always sends a top-level `context_management` field; strict anthropic-compatible gateways reject it. The dedicated context-editing 400-fallback only fired when OmniRoute's own `contextEditing` feature was enabled (default off), so a client-sent field passed through untouched and 400'd. `context_management` is now in the generic reactive field-strip list, so it's stripped-and-retried once regardless of the feature flag (with correct request re-signing for claude-compatible relays). Regression guard: `tests/unit/provider-field-strips.test.ts`. (thanks @ohahe52-dot)
 - **fix(network):** enable **RFC 8305 Happy Eyeballs** (`autoSelectFamily`) on the direct-egress undici dispatcher. When DNS returns both IPv6 (AAAA) and IPv4 (A) and the IPv6 route is broken (e.g. a NAT64 `64:ff9b::` prefix without routing), undici tried IPv6 first and hung until `ETIMEDOUT` (then a 502 + account lockout), even though `curl` reached the same host. The direct dispatcher now races both families and uses whichever connects first. Proxy paths pin family via `proxyTls` and are unaffected. Regression guard: `tests/unit/direct-dispatcher-pipelining-4580.test.ts`. (thanks @adentdk)
 - **fix(combo):** round-robin now advances the rotation pointer past the model that **actually served**, not the eagerly-scheduled one. With `stickyLimit: 1` (true round-robin), when the scheduled model failed and a *different* model served via fallback, the counter had already advanced +1 from the scheduled index — so the next request reused the fallback-served model, degrading round-robin into hot-spotting on whichever model was healthy. The pointer now advances to the served index + 1 (mirroring the sticky-limit>1 path). Session-stickiness (#3825) and distribution are preserved. Regression guard: `tests/unit/combo-rr-fallback-advance-948.test.ts`. (thanks @binsarjr)

open-sse/executors/default.ts

@@ -17,6 +17,10 @@ import {
 import { isOfficialAnthropicBaseUrl } from "../utils/anthropicHost.ts";
 import { applyProviderRequestDefaults } from "../services/providerRequestDefaults.ts";
 import { stripUnsupportedParams } from "../translator/paramSupport.ts";
+import {
+  injectReasoningContentForThinkingModel,
+  isThinkingMessageModel,
+} from "../utils/reasoningContentInjector.ts";
 import {
   detectFormat,
   getOpenAICompatibleType,
@@ -695,6 +699,23 @@ export class DefaultExecutor extends BaseExecutor {
       this.ensureThinkingBudget(withDefaults as Record<string, unknown>, model);
     }
 
+    // 9router#1480: the native Moonshot `kimi` provider (executor "default")
+    // is a thinking-mode upstream that 400s with "reasoning_content must be
+    // passed back" when a prior assistant turn lacks it. OpencodeExecutor
+    // already injects a placeholder for OpenCode-routed thinking models; the
+    // direct kimi connection hit neither injection path. Scope to `kimi` so
+    // gateway-served models that merely match the thinking-model name pattern
+    // (and may reject an extra field) are unaffected.
+    if (this.provider === "kimi") {
+      const outboundModel =
+        typeof (withDefaults as Record<string, unknown>)?.model === "string"
+          ? ((withDefaults as Record<string, unknown>).model as string)
+          : model;
+      if (isThinkingMessageModel(outboundModel)) {
+        withDefaults = injectReasoningContentForThinkingModel(withDefaults);
+      }
+    }
+
     return withDefaults;
   }
 

tests/unit/kimi-native-reasoning-injected-1480.test.ts

@@ -0,0 +1,65 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { DefaultExecutor } from "../../open-sse/executors/default.ts";
+
+/**
+ * Regression guard for upstream 9router#1480.
+ *
+ * The native Moonshot `kimi` provider (executor "default") is a thinking-mode
+ * upstream that returns 400 "reasoning_content must be passed back" when a prior
+ * assistant turn in the history lacks `reasoning_content`. OpencodeExecutor
+ * already injects a placeholder for OpenCode-routed thinking models, but the
+ * direct kimi connection went through DefaultExecutor, which did not — so
+ * multi-turn kimi conversations 400'd. The injection must fire for `kimi`, and
+ * must NOT fire for unrelated providers that merely serve a matching model name.
+ */
+
+const STREAM = true;
+const CREDENTIALS = { apiKey: "k" } as Record<string, unknown>;
+
+function multiTurnBody(model: string) {
+  return {
+    model,
+    stream: STREAM,
+    messages: [
+      { role: "user", content: "hi" },
+      { role: "assistant", content: "previous answer" }, // no reasoning_content
+      { role: "user", content: "follow up" },
+    ],
+  };
+}
+
+test("DefaultExecutor(kimi) injects reasoning_content on assistant turns that lack it", () => {
+  const out = new DefaultExecutor("kimi").transformRequest(
+    "kimi-k2.6",
+    multiTurnBody("kimi-k2.6"),
+    STREAM,
+    CREDENTIALS
+  ) as Record<string, unknown>;
+  const messages = out.messages as Array<Record<string, unknown>>;
+  const assistant = messages.find((m) => m.role === "assistant") as Record<string, unknown>;
+  assert.equal(
+    typeof assistant.reasoning_content === "string" &&
+      (assistant.reasoning_content as string).length > 0,
+    true,
+    "kimi assistant message must carry a non-empty reasoning_content placeholder"
+  );
+});
+
+test("DefaultExecutor(openai) does NOT inject reasoning_content (scoped to kimi)", () => {
+  // A non-kimi provider must not gain the injection even for a thinking-ish name.
+  const out = new DefaultExecutor("openai").transformRequest(
+    "kimi-k2.6",
+    multiTurnBody("kimi-k2.6"),
+    STREAM,
+    CREDENTIALS
+  ) as Record<string, unknown>;
+  const messages = out.messages as Array<Record<string, unknown>>;
+  const assistant = messages.find((m) => m.role === "assistant") as Record<string, unknown>;
+  assert.equal(
+    Object.prototype.hasOwnProperty.call(assistant, "reasoning_content"),
+    false,
+    "non-kimi providers must not be given a reasoning_content placeholder"
+  );
+});