[defangdevs]

Problem

https://ask.defang.io/data/knowledge_base.json is served uncompressed at ~35 MB. defang mcp serve downloads it synchronously before answering the MCP initialize request, which regularly exceeds client-side MCP connect timeouts (e.g. Claude Code's 30s), so the Defang MCP server fails to connect.

Fix

This implements suggestion 1 from the issue: serve the file gzip-compressed.

• get_knowledge_base.py now writes a knowledge_base.json.gz sibling next to knowledge_base.json on every rebuild (write_compressed_knowledge_base(), called at the end of recursive_parse_directory), so it's regenerated automatically whenever the knowledge base is rebuilt (manual run or /trigger-rebuild).
• /data/<name> in app.py now serves that .gz sibling with Content-Encoding: gzip and the correct Content-Type/Content-Disposition when the request sends Accept-Encoding: gzip and the sibling exists, falling back to the uncompressed file otherwise (e.g. right after a fresh deploy, before the first rebuild has produced a .gz). No CLI-side change is needed — Go's net/http client already sends Accept-Encoding: gzip and transparently decodes it.
• .gz files under app/data/ are gitignored; the ~35 MB production knowledge base is generated at deploy/rebuild time, not committed (the committed knowledge_base.json is a small dev seed).

Per the issue's own measurement, gzip gets ~4x smaller on this content, which should bring the download well under typical MCP connect timeouts.

Out of scope here (left for follow-up, possibly separate issues):

• Suggestion 2 (conditional requests / ETag) — send_from_directory already sets ETag/Last-Modified locally; the issue notes ETag isn't visible in production responses, which points at something stripping it between the app and the client (proxy/CDN), not at the Flask app.
• Suggestions 3-4 (CLI-side background fetch, shrinking the file itself) are bigger changes in a different repo (DefangLabs/defang) or touch content generation, respectively.

Testing

• ruff check / ruff format --check pass on both changed Python files.
• Existing test_get_knowledge_base.py unit tests still pass.
• Verified the new route logic end-to-end with a standalone Flask test-client script (not committed, this repo has no Flask route test harness): confirmed the gzip path returns Content-Encoding: gzip + correct Content-Type/Content-Disposition, decompresses to the exact original JSON, and that the no-Accept-Encoding path is byte-identical to the previous behavior.

Fixes #147

🤖 Generated with Claude Code