stitch::upload-to-stitch

Run the upload_to_stitch.py script with your project ID, file path, and API key. The script base64-encodes the file in-process and posts it to the Stitch BatchCreateScreens endpoint, supporting PNG, JPG, JPEG, and WebP formats.

MCP tool arguments are part of the model's output, so the model must re-emit the entire base64 file as generated text. A typical file's base64 encoding exceeds the ~16K output token limit, truncating the payload mid-string and corrupting the upload.

The script supports PNG, JPG, JPEG, and WebP images uploaded as screenshots, plus HTML and Markdown files uploaded as document screens. MIME type is auto-detected from the file extension.

Check your MCP server configuration files: .gemini/antigravity/mcp_config.json for Antigravity, ~/.gemini/settings.json for Gemini CLI, or ~/.claude.json for Claude Code. The key is in the X-Goog-Api-Key header or auth argument.

The SSLCertVerificationError occurs when Python lacks root certificate authorities. Install the certifi package, which the script uses automatically, or set the SSL_CERT_FILE environment variable to certifi's CA bundle path.