fix(opencode): route Muse Spark models to Responses API and declare vision

Route all Muse Spark models (not just 1.2) on OpenCode Free to
/zen/v1/responses via isMuseSparkModel(), fixing HTTP 500 on
muse-spark-1.3-contributor-free. Declare vision:true on Muse Spark
models so image input is no longer stripped; register 1.3 in the
registry and capabilities. Scoped to opencode only — other providers
keep Chat Completions routing.

open-sse/config/providerModels.js

@@ -3,7 +3,8 @@ import REGISTRY from "../providers/registry/index.js";
 // PROVIDER_MODELS now built from providers/registry (transport + models co-located)
 import { PROVIDER_MODELS } from "../providers/index.js";
 import { modelQuotaFamily, modelStrip, modelTargetFormat, modelSupportedFormats, normalizeModelId } from "../providers/models/schema.js";
-import { CODEX_REVIEW_SUFFIX } from "../providers/models/helpers.js";
+import { CODEX_REVIEW_SUFFIX, isMuseSparkModel } from "../providers/models/helpers.js";
+import { FORMATS } from "../translator/formats.js";
 export { PROVIDER_MODELS };
 
 
@@ -49,6 +50,9 @@ export function findModelName(aliasOrId, modelId) {
 }
 
 export function getModelTargetFormat(aliasOrId, modelId) {
+  if ((!aliasOrId || aliasOrId === "oc" || aliasOrId === "opencode") && isMuseSparkModel(modelId)) {
+    return FORMATS.OPENAI_RESPONSES;
+  }
   const models = PROVIDER_MODELS[aliasOrId];
   if (!models) return null;
   return modelTargetFormat(findModel(models, modelId, aliasOrId));

open-sse/executors/opencode.js

@@ -4,10 +4,14 @@ import { PROVIDERS } from "../config/providers.js";
 import { getThinkingLevels } from "../providers/thinkingLevels.js";
 import { injectReasoningContent } from "../utils/reasoningContentInjector.js";
 import { resolveSessionId } from "../utils/sessionManager.js";
+import { isMuseSparkModel } from "../providers/models/helpers.js";
 
 const OPENCODE_UA = "opencode";
 // Models served by /zen/v1/responses; every other model stays on /chat/completions.
-const RESPONSES_MODELS = new Set(["muse-spark-1.2-contributor-free"]);
+const RESPONSES_MODELS = new Set([
+  "muse-spark-1.2-contributor-free",
+  "muse-spark-1.3-contributor-free",
+]);
 
 function generateRequestId() {
   return `msg_${crypto.randomUUID().replace(/-/g, "")}`;
@@ -23,7 +27,8 @@ function baseModelId(model) {
 }
 
 function isResponsesModel(model) {
-  return RESPONSES_MODELS.has(baseModelId(model));
+  const base = baseModelId(model);
+  return RESPONSES_MODELS.has(base) || isMuseSparkModel(base);
 }
 
 function resolveOpencodeSession(body, credentials) {

open-sse/providers/capabilities.js

@@ -127,8 +127,10 @@ export const MODEL_CAPABILITIES = {
   "kimi-for-coding-highspeed": { vision: true, videoInput: true, reasoning: true, thinkingFormat: "kimi", thinkingCanDisable: false, contextWindow: 262144, maxOutput: 65536 },
   "kimi-k2.7-code":    { vision: true, videoInput: true, reasoning: true, thinkingFormat: "kimi", thinkingCanDisable: false, contextWindow: 262144, maxOutput: 65536 },
   "kimi-k2.7-code-highspeed": { vision: true, videoInput: true, reasoning: true, thinkingFormat: "kimi", thinkingCanDisable: false, contextWindow: 262144, maxOutput: 65536 },
-  // OpenCode Free Muse Spark — OpenAI Responses reasoning supports up to xhigh.
-  "muse-spark-1.2-contributor-free": { reasoning: true, thinkingFormat: "openai", contextWindow: 1048576, maxOutput: 131072 },
+  // OpenCode Free Muse Spark — multimodal (text+image per models.dev meta/muse-spark)
+  // via OpenAI Responses input_image; reasoning supports up to xhigh.
+  "muse-spark-1.2-contributor-free": { vision: true, reasoning: true, thinkingFormat: "openai", contextWindow: 1048576, maxOutput: 131072 },
+  "muse-spark-1.3-contributor-free": { vision: true, reasoning: true, thinkingFormat: "openai", contextWindow: 1048576, maxOutput: 131072 },
 };
 
 const KIRO_GPT_5_6_CAPABILITIES = { vision: true, reasoning: true, search: true, thinkingFormat: "openai", contextWindow: 272000, maxOutput: 128000 };
@@ -337,6 +339,9 @@ export const PATTERN_CAPABILITIES = [
   { pattern: "*laguna-s-2.1*",  caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 1000000, maxOutput: 32000 } },
   { pattern: "*laguna*",        caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 200000, maxOutput: 32000 } },
 
+
+  // ── OpenCode Free Muse Spark (multimodal text+image; OpenAI Responses reasoning supports up to xhigh) ─
+  { pattern: "*muse*spark*",    caps: { vision: true, reasoning: true, thinkingFormat: "openai", contextWindow: 1048576, maxOutput: 131072 } },
   // ── Others ───────────────────────────────────────────────────────
   { pattern: "*hunyuan*",       caps: { reasoning: true, thinkingFormat: "hunyuan", contextWindow: 262144, maxOutput: 262144 } },
   { pattern: "hy3*",            caps: { reasoning: true, thinkingFormat: "hunyuan", contextWindow: 262144, maxOutput: 262144 } },

open-sse/providers/models/helpers.js

@@ -18,3 +18,10 @@ export function withCodexReviewModels(models) {
     ];
   });
 }
+
+export function isMuseSparkModel(modelId) {
+  if (!modelId || typeof modelId !== "string") return false;
+  const clean = modelId.replace(/\([^()]+\)\s*$/, "").trim();
+  const base = clean.includes("/") ? clean.split("/").pop() : clean;
+  return /^muse[-_]?spark(?:$|[-_:.\s])/i.test(base);
+}

open-sse/providers/registry/opencode.js

@@ -20,9 +20,10 @@ export default {
     noAuth: true,
   },
   models: [
-    // Only this model is served by /zen/v1/responses; the rest stay on
+    // Muse Spark models are served by /zen/v1/responses; the rest stay on
     // /chat/completions, so the format is declared per-model, not per-provider.
     { id: "muse-spark-1.2-contributor-free", name: "Muse Spark 1.2 Contributor Free", targetFormat: "openai-responses" },
+    { id: "muse-spark-1.3-contributor-free", name: "Muse Spark 1.3 Contributor Free", targetFormat: "openai-responses" },
   ],
   modelsFetcher: { url: "https://opencode.ai/zen/v1/models", type: "opencode-free" },
   passthroughModels: true,