feat(ui): replace Streamlit UI with a server-rendered FastAPI + Jinja web UI

.github/workflows/ci-tests.yml

@@ -39,7 +39,7 @@ jobs:
           enable-cache: true
 
       - name: Install
-        run: uv pip install --system -e ".[dev,server,openai]"
+        run: uv pip install --system -e ".[dev,server,ui,openai]"
 
       - name: Lint (ruff)
         run: ruff check .

.github/workflows/docker-beta.yml

@@ -2,7 +2,7 @@ name: Docker (beta)
 
 # Build the container images on every PR (validation only, no push) and publish
 # the beta channel to GHCR on every push to master. Two images are built from one
-# Dockerfile: the HTTP API (:beta) and the Streamlit UI (:beta-ui).
+# Dockerfile: the HTTP API (:beta) and the web UI (:beta-ui).
 on:
   push:
     branches: [master]
@@ -53,7 +53,7 @@ jobs:
         include:
           - target: server   # HTTP/REST API
             suffix: ""
-          - target: ui        # Streamlit UI
+          - target: ui        # Web UI
             suffix: "-ui"
     steps:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6

.gitignore

@@ -38,9 +38,6 @@ node_modules/
 # Ignore Git directory
 .git/
 
-# Ignore Streamlit temporary files
-.streamlit/
-
 # Ignore logs and temporary files
 *.log
 *.tmp

AGENTS.md

@@ -8,7 +8,7 @@
 - `coderag/store/`: `sqlite_store.py` (source of truth + FTS5) and `vector_index.py` (FAISS Flat/IVF cache).
 - `coderag/retrieval/`: Hybrid dense + BM25 search fused with RRF.
 - `coderag/indexer.py`, `coderag/watch.py`: Incremental indexing and the debounced watcher.
-- `coderag/surfaces/`: `cli.py`, `http_api.py` (FastAPI), `streamlit_app.py` — thin adapters over the facade.
+- `coderag/surfaces/`: `cli.py`, `http_api.py` (FastAPI), `webui.py` — thin adapters over the facade.
 - `tests/`: pytest suite (offline by default via the `fake` provider; real model behind `-m integration`).
 - `example.env` → copy to `.env`; CI lives in `.github/`.
 

DEVELOPMENT.md

@@ -30,7 +30,7 @@ coderag/
 │   ├── sqlite_store.py #   files/chunks/vectors + FTS5 lexical search
 │   └── vector_index.py #   FaissVectorIndex: Flat (exact) / IVF (scale)
 ├── retrieval/          # Hybrid search: dense + BM25, fused with RRF
-└── surfaces/           # cli.py · http_api.py (FastAPI) · streamlit_app.py
+└── surfaces/           # cli.py · http_api.py (FastAPI) · webui.py
 ```
 
 ### Design invariants (don't break these)

Dockerfile

@@ -2,7 +2,7 @@
 
 # CodeRAG container images — two build targets share one base:
 #   docker build --target server -t coderag    .   # HTTP/REST API  (port 8000)
-#   docker build --target ui     -t coderag-ui .   # Streamlit UI    (port 8501)
+#   docker build --target ui     -t coderag-ui .   # Web UI          (port 8501)
 # Published to GHCR as :beta / :beta-ui by .github/workflows/docker-beta.yml.
 
 ARG PYTHON_VERSION=3.12
@@ -47,18 +47,16 @@ HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \
 ENTRYPOINT ["coderag"]
 CMD ["serve", "--host", "0.0.0.0", "--port", "8000"]
 
-# ---------- Streamlit UI image ----------
+# ---------- Web UI image ----------
 FROM base AS ui
 # Include the LLM answer backends (openai covers self-hosted OpenAI-compatible
 # servers like Ollama/vLLM too) so the UI's "Generate LLM answer" works.
 RUN uv pip install --system --no-cache ".[ui,openai,anthropic]"
-# `coderag ui` shells out to `streamlit run`; configure the server via env vars.
-ENV STREAMLIT_SERVER_ADDRESS=0.0.0.0 \
-    STREAMLIT_SERVER_PORT=8501 \
-    STREAMLIT_SERVER_HEADLESS=true \
-    STREAMLIT_BROWSER_GATHER_USAGE_STATS=false
+# `coderag ui` serves the FastAPI/Jinja UI via uvicorn; host/port come from env.
+ENV CODERAG_UI_HOST=0.0.0.0 \
+    CODERAG_UI_PORT=8501
 USER coderag
 EXPOSE 8501
 HEALTHCHECK --interval=30s --timeout=5s --start-period=30s --retries=3 \
-  CMD ["python", "-c", "import sys,urllib.request as u; sys.exit(0 if u.urlopen('http://127.0.0.1:8501/_stcore/health').status==200 else 1)"]
+  CMD ["python", "-c", "import sys,urllib.request as u; sys.exit(0 if u.urlopen('http://127.0.0.1:8501/healthz').status==200 else 1)"]
 CMD ["coderag", "ui"]

README.md

@@ -31,15 +31,15 @@ codebases**. Use it from the **CLI**, embed it as a **Python library**, self-hos
 - **Hybrid retrieval.** Dense vector search **+** BM25 keyword search, fused with Reciprocal Rank Fusion. Great at both "what does this *mean*" and exact-identifier lookups.
 - **Incremental & live.** Content-hashed indexing only re-embeds files that changed; a debounced watcher keeps the index current as you code. No duplicate or stale vectors.
 - **Built to scale.** Exact `Flat` search for small repos, automatic switch to approximate `IVF` past a threshold so it stays fast at 100k+ chunks.
-- **Four surfaces, one engine.** CLI · Python library · HTTP/REST · Streamlit UI — all thin wrappers over the same `CodeRAG` object.
+- **Four surfaces, one engine.** CLI · Python library · HTTP/REST · web UI — all thin wrappers over the same `CodeRAG` object.
 
 ## 🚀 Quick start
 
 ```bash
 pip install -e .            # core engine (local embeddings included)
 # optional extras:
 pip install -e ".[server]"     # HTTP/REST API
-pip install -e ".[ui]"         # Streamlit web UI
+pip install -e ".[ui]"         # built-in web UI (FastAPI + Jinja + Pygments)
 pip install -e ".[openai]"     # OpenAI (or self-hosted OpenAI-compatible) embeddings / answers
 pip install -e ".[anthropic]"  # Anthropic (Claude) LLM answers
 pip install -e ".[all]"        # everything above
@@ -107,9 +107,13 @@ Self-host it once and point any number of custom apps or teammates at a big shar
 
 ### Web UI  (`coderag ui`)
 
-Streamlit app: search box, retrieved chunks with `path:line` citations and similarity
-scores, a one-click **Reindex** button, and an optional streamed LLM answer (when an
-OpenAI/Anthropic key or a self-hosted endpoint is configured).
+A built-in, server-rendered web UI (FastAPI + Jinja, syntax highlighting via Pygments):
+a search box with language/kind/path filters, results with `path:line` citations and
+similarity scores, an in-browser **file viewer** (cited lines highlighted), a **file
+browser**, index status, a one-click **Reindex**, and an optional streamed LLM answer
+(when an OpenAI/Anthropic key or a self-hosted endpoint is configured). It is progressively
+enhanced — every page works with JavaScript disabled, and there's no CDN/runtime network
+dependency, so it stays local-first.
 
 ## 🐳 Docker (beta)
 
@@ -128,7 +132,7 @@ curl "localhost:8000/search?q=where%20is%20retry%20handled&k=5"
 ```
 
 ```bash
-# Streamlit UI on :8501
+# Web UI on :8501
 docker run --rm -p 8501:8501 \
   -v "$PWD:/workspace:ro" -v coderag-index:/data \
   ghcr.io/neverdecel/coderag:beta-ui
@@ -237,7 +241,7 @@ Apache License 2.0 — see [LICENSE](LICENSE-2.0.txt).
 
 [FAISS](https://github.com/facebookresearch/faiss) · [fastembed](https://github.com/qdrant/fastembed) ·
 [tree-sitter](https://tree-sitter.github.io/tree-sitter/) · [FastAPI](https://fastapi.tiangolo.com/) ·
-[Streamlit](https://streamlit.io/) · [watchdog](https://github.com/gorakhargosh/watchdog)
+[Jinja](https://jinja.palletsprojects.com/) · [Pygments](https://pygments.org/) · [watchdog](https://github.com/gorakhargosh/watchdog)
 
 ---
 

coderag/store/sqlite_store.py

@@ -118,6 +118,22 @@ def all_file_paths(self) -> List[str]:
             rows = self._conn.execute("SELECT path FROM files").fetchall()
         return [r["path"] for r in rows]
 
+    def distinct_languages(self) -> List[str]:
+        """Languages present in the index, sorted — used to populate UI filters."""
+        with self._lock:
+            rows = self._conn.execute(
+                "SELECT DISTINCT language FROM chunks ORDER BY language"
+            ).fetchall()
+        return [r["language"] for r in rows]
+
+    def distinct_kinds(self) -> List[str]:
+        """Chunk kinds present in the index, sorted — used to populate UI filters."""
+        with self._lock:
+            rows = self._conn.execute(
+                "SELECT DISTINCT kind FROM chunks ORDER BY kind"
+            ).fetchall()
+        return [r["kind"] for r in rows]
+
     def upsert_file(
         self, path: str, language: str, content_hash: str, mtime: float
     ) -> int:

coderag/surfaces/__init__.py

@@ -1 +1 @@
-"""User-facing surfaces: CLI, HTTP server, and Streamlit UI — all thin over the facade."""
+"""User-facing surfaces: CLI, HTTP server, and web UI — all thin over the facade."""

coderag/surfaces/cli.py

@@ -8,6 +8,7 @@
 import argparse
 import json
 import logging
+import os
 import sys
 import textwrap
 from pathlib import Path
@@ -113,25 +114,21 @@ def cmd_serve(args: argparse.Namespace) -> int:
 
 
 def cmd_ui(args: argparse.Namespace) -> int:
-    import subprocess
-
-    app = Path(__file__).with_name("streamlit_app.py")
     try:
-        return subprocess.call(
-            ["streamlit", "run", str(app), "--", *_passthrough(args)]
-        )
-    except FileNotFoundError:
-        print("Streamlit is not installed. Install with: pip install 'coderag[ui]'")
+        from coderag.surfaces.webui import run_ui
+    except ImportError:
+        print("The web UI needs extra deps. Install with: pip install 'coderag[ui]'")
         return 1
+    cr = CodeRAG(_build_config(args))
+    host = args.host or os.getenv("CODERAG_UI_HOST") or "127.0.0.1"
+    port = args.port if args.port is not None else _env_port("CODERAG_UI_PORT", 8501)
+    run_ui(cr, host=host, port=port)
+    return 0
 
 
-def _passthrough(args: argparse.Namespace) -> List[str]:
-    out: List[str] = []
-    if getattr(args, "watched_dir", None):
-        out += ["--watched-dir", str(args.watched_dir)]
-    if getattr(args, "store_dir", None):
-        out += ["--store-dir", str(args.store_dir)]
-    return out
+def _env_port(key: str, default: int) -> int:
+    raw = os.getenv(key)
+    return int(raw) if raw and raw.isdigit() else default
 
 
 # --- parser ---
@@ -197,7 +194,15 @@ def build_parser() -> argparse.ArgumentParser:
     _add_common(p_serve)
     p_serve.set_defaults(func=cmd_serve)
 
-    p_ui = sub.add_parser("ui", help="Launch the Streamlit web UI.")
+    p_ui = sub.add_parser("ui", help="Launch the built-in web UI.")
+    p_ui.add_argument(
+        "--host",
+        default=None,
+        help="Bind address (default 127.0.0.1 / CODERAG_UI_HOST).",
+    )
+    p_ui.add_argument(
+        "--port", type=int, default=None, help="Port (default 8501 / CODERAG_UI_PORT)."
+    )
     _add_common(p_ui)
     p_ui.set_defaults(func=cmd_ui)