fix(providers): route Muse Spark to the Responses API on opencode-zen and opencode-go too

open-sse/config/providers/registry/opencode/go/index.ts

@@ -138,6 +138,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     {
       id: "muse-spark-1.2-contributor-minimal",
@@ -148,6 +149,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     {
       id: "muse-spark-1.2-contributor-low",
@@ -158,6 +160,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     {
       id: "muse-spark-1.2-contributor-medium",
@@ -168,6 +171,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     {
       id: "muse-spark-1.2-contributor-high",
@@ -178,6 +182,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     {
       id: "muse-spark-1.2-contributor-xhigh",
@@ -188,6 +193,7 @@ export const opencode_goProvider: RegistryEntry = {
       supportsVision: true,
       supportsAudio: true,
       supportsVideo: true,
+      targetFormat: "openai-responses",
     },
     // #8353: Grok 4.5 + effort tiers from the OpenCode Go registry.
     { id: "grok-4.5", name: "Grok 4.5", supportsReasoning: true },

open-sse/config/providers/registry/opencode/zen/index.ts

@@ -51,7 +51,25 @@ export const opencode_zenProvider: RegistryEntry = {
     { id: "grok-4.6", name: "Grok 4.6" },
 
     // ── Muse ───────────────────────────────────────────────────
-    { id: "muse-spark-1.2", name: "Muse Spark 1.2" },
+    // Muse Spark is served by OpenCode Zen only on the OpenAI Responses API
+    // endpoint, not /chat/completions (see the opencode provider's own
+    // muse-spark entries, #10874/#10867) — this provider is a separate
+    // registry entry for the same upstream and never got the same
+    // targetFormat declaration, so requests routed here still hit
+    // /chat/completions with a mismatched or unanswerable body and the
+    // upstream returns an empty message.
+    {
+      id: "muse-spark-1.2",
+      name: "Muse Spark 1.2",
+      supportsReasoning: true,
+      targetFormat: "openai-responses",
+    },
+    {
+      id: "muse-spark-1.2-contributor-free",
+      name: "Muse Spark 1.2 Contributor Free",
+      supportsReasoning: true,
+      targetFormat: "openai-responses",
+    },
 
     // ── DeepSeek ────────────────────────────────────────────────
     { id: "deepseek-v4-pro", name: "DeepSeek V4 Pro" },

tests/unit/opencode-zen-muse-spark-targetformat-11046.test.ts

@@ -0,0 +1,43 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { opencode_zenProvider } from "../../open-sse/config/providers/registry/opencode/zen/index.ts";
+import { opencode_goProvider } from "../../open-sse/config/providers/registry/opencode/go/index.ts";
+
+// opencode-zen and opencode-go both serve the same upstream family
+// (opencode.ai/zen/*) as the opencode provider for Muse Spark, but neither
+// got the targetFormat:"openai-responses" declaration that #10874 added to
+// the opencode provider's entries — so requests routed to either still hit
+// /chat/completions and the upstream returns an empty message.
+test("muse-spark-1.2 and muse-spark-1.2-contributor-free route to the Responses API on opencode-zen too", () => {
+  for (const id of ["muse-spark-1.2", "muse-spark-1.2-contributor-free"]) {
+    const model = opencode_zenProvider.models.find((m) => m.id === id);
+    assert.ok(model, `${id} should be registered in the opencode-zen provider`);
+    assert.equal(
+      model?.targetFormat,
+      "openai-responses",
+      `${id} must target the Responses API, not the default chat/completions pass-through`
+    );
+    assert.equal(model?.supportsReasoning, true);
+  }
+});
+
+test("all muse-spark-1.2-contributor effort-tier entries route to the Responses API on opencode-go too", () => {
+  const ids = [
+    "muse-spark-1.2-contributor",
+    "muse-spark-1.2-contributor-minimal",
+    "muse-spark-1.2-contributor-low",
+    "muse-spark-1.2-contributor-medium",
+    "muse-spark-1.2-contributor-high",
+    "muse-spark-1.2-contributor-xhigh",
+  ];
+  for (const id of ids) {
+    const model = opencode_goProvider.models.find((m) => m.id === id);
+    assert.ok(model, `${id} should be registered in the opencode-go provider`);
+    assert.equal(
+      model?.targetFormat,
+      "openai-responses",
+      `${id} must target the Responses API, not the default chat/completions pass-through`
+    );
+  }
+});