feat(embed): static-model telemetry + release-independent model fetch

- Telemetry: mcp.start now emits `embeddingModel` (static / bge-small /
  jina-code-v2 / granite-97m) via EmbeddingBackend::telemetry_id — static
  adoption is queryable in PostHog (and the extension config snapshot already
  reports the setting now that 'static' is valid).
- scripts/fetch-static-model.sh: fetch the distilled model from the
  release-independent `model` GitHub release (package-time bundle or manual).
- MCP postinstall: best-effort static-model fetch (skip via
  CODEGRAPH_SKIP_MODEL_FETCH; never fails install).
- VS Code: default CODEGRAPH_STATIC_MODEL to the bundled bin/jina-code-static-256
  when embeddingModel=static and staticModelPath is unset.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: anvanster

crates/codegraph-memory/src/embedding/mod.rs

@@ -69,6 +69,16 @@ impl EmbeddingBackend {
             ),
         }
     }
+
+    /// Short, stable tag for telemetry / adoption grouping.
+    pub fn telemetry_id(&self) -> &'static str {
+        match self {
+            Self::Static(_) => "static",
+            Self::Fastembed(CodeGraphEmbeddingModel::BgeSmall) => "bge-small",
+            Self::Fastembed(CodeGraphEmbeddingModel::JinaCodeV2) => "jina-code-v2",
+            Self::Fastembed(CodeGraphEmbeddingModel::Granite97mMultilingualR2) => "granite-97m",
+        }
+    }
 }
 
 /// Resolve the static-model directory: `CODEGRAPH_STATIC_MODEL` env override,

crates/codegraph-server/src/mcp/server.rs

@@ -1395,6 +1395,7 @@ impl McpServer {
             "os": std::env::consts::OS,
             "arch": std::env::consts::ARCH,
             "version": crate::metadata::VERSION,
+            "embeddingModel": self.backend.memory_manager.embedding_telemetry_id(),
         }));
 
         loop {

crates/codegraph-server/src/memory.rs

@@ -208,6 +208,12 @@ impl MemoryManager {
         }
     }
 
+    /// Short telemetry tag for the configured embedding backend
+    /// (`static` / `bge-small` / `jina-code-v2` / `granite-97m`).
+    pub fn embedding_telemetry_id(&self) -> &'static str {
+        self.embedding_model.telemetry_id()
+    }
+
     /// Initialize the memory manager with workspace path
     ///
     /// Resolves the global data directory at `~/.codegraph/projects/<slug>/memory/`,

mcp-package/bin/postinstall.js

@@ -57,6 +57,30 @@ try {
   console.warn(`  ${err.message}`);
 }
 
+// Fetch the distilled static embedding model (best-effort) from the
+// release-independent `model` GitHub release. Only needed for
+// `--embedding-model static`; skipped if already present or if
+// CODEGRAPH_SKIP_MODEL_FETCH is set. Never fails the install.
+if (!process.env.CODEGRAPH_SKIP_MODEL_FETCH) {
+  const MODEL = "jina-code-static-256";
+  const modelDir = path.join(os.homedir(), ".codegraph", "static_models", MODEL);
+  if (!fs.existsSync(path.join(modelDir, "model.safetensors"))) {
+    try {
+      fs.mkdirSync(modelDir, { recursive: true });
+      const url = `https://github.com/codegraph-ai/CodeGraph/releases/download/model/${MODEL}.tar.gz`;
+      const tgz = path.join(modelDir, "_model.tar.gz");
+      execFileSync("curl", ["-fsSL", url, "-o", tgz], { timeout: 180000 });
+      execFileSync("tar", ["xzf", tgz, "-C", modelDir], { timeout: 60000 });
+      fs.unlinkSync(tgz);
+      console.log(`✓ codegraph-mcp: static embedding model ready (${modelDir})`);
+    } catch {
+      console.warn(
+        `ℹ codegraph-mcp: static model not fetched (optional — only for --embedding-model static)`
+      );
+    }
+  }
+}
+
 // Hint about the optional Claude Code hook. Installation is opt-in to avoid
 // silently modifying the user's ~/.claude/settings.json. Both Unix
 // (bash) and Windows (PowerShell) variants are shipped — the installer

scripts/fetch-static-model.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+# Fetch the distilled static embedding model from the release-independent
+# `model` GitHub release (decoupled from versioned releases — bumping the app
+# version never requires re-uploading the model).
+#
+# Used two ways:
+#   • Package time — place the model into the VS Code extension bundle:
+#       scripts/fetch-static-model.sh vscode/bin/jina-code-static-256
+#   • Manually — populate the server's default resolve path:
+#       scripts/fetch-static-model.sh
+#
+# Usage: scripts/fetch-static-model.sh [DEST_DIR] [MODEL_NAME]
+#   DEST_DIR    default ~/.codegraph/static_models/<MODEL_NAME>
+#   MODEL_NAME  default jina-code-static-256
+#
+# Expects a `<MODEL_NAME>.tar.gz` asset on the `model` release whose contents
+# are the model files at the archive root, created with:
+#   tar czf jina-code-static-256.tar.gz -C <model-dir> .
+set -euo pipefail
+
+MODEL="${2:-jina-code-static-256}"
+DEST="${1:-$HOME/.codegraph/static_models/$MODEL}"
+URL="https://github.com/codegraph-ai/CodeGraph/releases/download/model/${MODEL}.tar.gz"
+
+mkdir -p "$DEST"
+echo "fetching ${MODEL}.tar.gz -> $DEST"
+curl -fsSL "$URL" | tar xz -C "$DEST"
+
+if [ ! -f "$DEST/model.safetensors" ]; then
+    echo "error: model.safetensors missing after extract — check the '$MODEL' release asset" >&2
+    exit 1
+fi
+echo "static model ready: $(ls "$DEST" | tr '\n' ' ')"

vscode/src/extension.ts

@@ -299,8 +299,10 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
         const wsFolder = vscode.workspace.workspaceFolders?.[0]?.uri;
         const cfg = vscode.workspace.getConfiguration('codegraph', wsFolder);
         const spawnEnv = { ...process.env };
-        const staticModelPath = cfg.get<string>('staticModelPath');
-        if (cfg.get<string>('embeddingModel') === 'static' && staticModelPath) {
+        if (cfg.get<string>('embeddingModel') === 'static') {
+            // staticModelPath override, else the model bundled next to the binary.
+            const staticModelPath = cfg.get<string>('staticModelPath')
+                || path.join(context.extensionPath, 'bin', 'jina-code-static-256');
             spawnEnv.CODEGRAPH_STATIC_MODEL = staticModelPath;
         }
         const child = cp.spawn(serverModule, [], { cwd: context.extensionPath, env: spawnEnv });