diff --git a/src/langsmith/troubleshooting-studio.mdx b/src/langsmith/troubleshooting-studio.mdx index 3ee179167a..d02bfe51d3 100644 --- a/src/langsmith/troubleshooting-studio.mdx +++ b/src/langsmith/troubleshooting-studio.mdx @@ -36,6 +36,53 @@ Use this URL in Safari to load Studio. Here, the `baseUrl` parameter specifies y Chrome and other Chromium browsers allow HTTP on localhost. Use `langgraph dev` without additional configuration. +## Chrome connection issues + +Starting with Chrome version 142, you may experience "Failed to initialize Studio" errors with "TypeError: Failed to fetch" when trying to connect [LangSmith Studio](/langsmith/studio) to your local development server via [`langgraph dev`](/langsmith/cli). This occurs even when the API server at `http://127.0.0.1:2024/docs` loads successfully. + +**Root Cause:** Chrome 142 fully enforces the Private Network Access (PNA) specification with no fallback, which blocks HTTPS sites (like `https://smith.langchain.com`) from accessing HTTP localhost servers by default. + +### Symptoms + +- Running `langgraph dev` starts the server successfully. +- Navigating to `http://127.0.0.1:2024/docs` shows the API documentation correctly. +- LangSmith Studio at `https://smith.langchain.com` shows: "Failed to initialize Studio - Please verify if the API server is running or accessible from the browser. TypeError: Failed to fetch". +- Browser console shows errors like: `Permission was denied for this request to access the 'unknown' address space`. + +### Solution: Allow local network access in Chrome + +1. Open LangSmith Studio at `https://smith.langchain.com` in Chrome. +2. Click the **lock icon** (or site information icon) to the left of the address bar. +3. Look for the **"Local network access"** option in the dropdown. +4. Change the setting from **"Ask (default)"** or **"Block"** to **"Allow"**. +5. Reload the page. + +Studio should now connect to your local development server successfully. + +### Additional troubleshooting + +**Check for browser extension conflicts** + +Browser extensions (especially Ollama Chrome extension or AI model extensions) can interfere with localhost connections: + +1. Disable all browser extensions temporarily. +2. Restart Chrome. +3. Try connecting to Studio again. +4. If it works, re-enable extensions one by one to identify the culprit. + +**Verify dependencies are up to date** + +```shell +pip install -U "langgraph-cli[inmem]" +``` + +**Clear browser cache and site data** + +1. In Chrome, go to **Settings** > **Privacy and Security** > **Site Settings**. +2. Find `https://smith.langchain.com` in the list. +3. Click **Clear data**. +4. Restart Chrome and try again. + ## Brave Connection Issues Brave blocks plain-HTTP traffic on localhost when Brave Shields are enabled. When running Studio with `langgraph dev`, you may see "Failed to load assistants" errors.