Read num_ctx from Ollama manifest params blob for accurate context window

/api/show가 cloud 모델의 PARAMETER num_ctx를 반환 안 하는 문제 해결.
매니페스트 → params 레이어 블롭 직접 파싱해서 num_ctx 우선 사용.
kimi-k2.6:cloud 1M으로 Modelfile 수정 후 정확히 표시됨.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/gateway/server-v2.ts

@@ -12938,6 +12938,29 @@ app.get('/api/ollama/models', async (_req, res) => {
 });
 
 // GET /api/model-context?model=<name>  — return context window size for a model
+/** Read num_ctx from the Ollama manifest's params blob (for cloud/custom models
+ *  where /api/show doesn't surface PARAMETER num_ctx in the parameters field). */
+function _readOllamaManifestNumCtx(modelName: string): number | null {
+  try {
+    const [nameTag, tag = 'latest'] = modelName.split(':');
+    const manifestDir = '/usr/share/ollama/.ollama/models/manifests/registry.ollama.ai/library';
+    const manifestPath = `${manifestDir}/${nameTag}/${tag}`;
+    if (!fs.existsSync(manifestPath)) return null;
+    const manifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'));
+    const blobsDir = '/usr/share/ollama/.ollama/models/blobs';
+    for (const layer of (manifest.layers || [])) {
+      if (layer.mediaType === 'application/vnd.ollama.image.params') {
+        const blobPath = `${blobsDir}/${layer.digest.replace(':', '-')}`;
+        if (fs.existsSync(blobPath)) {
+          const params = JSON.parse(fs.readFileSync(blobPath, 'utf8'));
+          if (typeof params.num_ctx === 'number') return params.num_ctx;
+        }
+      }
+    }
+  } catch {}
+  return null;
+}
+
 app.get('/api/model-context', async (req, res) => {
   const model = String(req.query.model || '').trim().toLowerCase();
   // Claude models: 200K (no local metadata)
@@ -12945,7 +12968,11 @@ app.get('/api/model-context', async (req, res) => {
     res.json({ contextWindow: 200000 });
     return;
   }
-  // For Ollama models, query /api/show directly
+  // Check manifest params blob first (catches PARAMETER num_ctx set via Modelfile)
+  const manifestCtx = _readOllamaManifestNumCtx(model);
+  if (manifestCtx) { res.json({ contextWindow: manifestCtx }); return; }
+
+  // Fall back to /api/show model_info
   try {
     const ollamaEndpoint = (getConfig().getConfig() as any).ollama?.endpoint || 'http://localhost:11434';
     const response = await fetch(`${ollamaEndpoint}/api/show`, {

src/providers/ollama-adapter.ts

@@ -226,6 +226,9 @@ export class OllamaAdapter implements LLMProvider {
   /** Return the model's native context_length from /api/show, cached per model. */
   private async getModelCtx(model: string): Promise<number> {
     if (this._ctxCache.has(model)) return this._ctxCache.get(model)!;
+    // Check manifest params blob first (PARAMETER num_ctx via Modelfile)
+    const manifestCtx = this._readManifestNumCtx(model);
+    if (manifestCtx) { this._ctxCache.set(model, manifestCtx); return manifestCtx; }
     try {
       const res = await fetch(`${this.endpoint}/api/show`, {
         method: 'POST',
@@ -241,15 +244,34 @@ export class OllamaAdapter implements LLMProvider {
             return mi[key];
           }
         }
-        // Fallback: num_ctx in parameters string
         const pm = String(data?.parameters || '').match(/\bnum_ctx\s+(\d+)/);
         if (pm) { const v = parseInt(pm[1], 10); this._ctxCache.set(model, v); return v; }
       }
     } catch {}
-    this._ctxCache.set(model, 8192); // unknown → keep safe default
+    this._ctxCache.set(model, 8192);
     return 8192;
   }
 
+  private _readManifestNumCtx(model: string): number | null {
+    try {
+      const [name, tag = 'latest'] = model.split(':');
+      const manifestPath = `/usr/share/ollama/.ollama/models/manifests/registry.ollama.ai/library/${name}/${tag}`;
+      if (!fs.existsSync(manifestPath)) return null;
+      const manifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'));
+      const blobsDir = '/usr/share/ollama/.ollama/models/blobs';
+      for (const layer of (manifest.layers || [])) {
+        if (layer.mediaType === 'application/vnd.ollama.image.params') {
+          const blobPath = `${blobsDir}/${layer.digest.replace(':', '-')}`;
+          if (fs.existsSync(blobPath)) {
+            const params = JSON.parse(fs.readFileSync(blobPath, 'utf8'));
+            if (typeof params.num_ctx === 'number') return params.num_ctx;
+          }
+        }
+      }
+    } catch {}
+    return null;
+  }
+
   async chat(messages: ChatMessage[], model: string, options?: ChatOptions): Promise<ChatResult> {
     const workspacePath = getConfig().getConfig().workspace?.path;
     // Ollama requires the last message to be user or tool — strip trailing assistant messages