diff --git a/python/ebook_search/api/__init__.py b/python/ebook_search/api/__init__.py
new file mode 100644
index 0000000..297fdb0
--- /dev/null
+++ b/python/ebook_search/api/__init__.py
@@ -0,0 +1 @@
+"""Web and external API adapters for EPUB search."""
diff --git a/python/ebook_search/api/bm25_tasks.py b/python/ebook_search/api/bm25_tasks.py
new file mode 100644
index 0000000..a211d45
--- /dev/null
+++ b/python/ebook_search/api/bm25_tasks.py
@@ -0,0 +1,58 @@
+"""Background BM25 refresh tasks for the web app."""
+
+from __future__ import annotations
+
+import logging
+from threading import Timer
+from typing import TYPE_CHECKING
+
+from sqlalchemy.orm import Session
+
+from python.ebook_search.bm25_corpus import refresh_bm25_corpus
+
+if TYPE_CHECKING:
+    from fastapi import FastAPI
+    from sqlalchemy.engine import Engine
+
+    from python.ebook_search.config import EbookSearchConfig
+
+logger = logging.getLogger(__name__)
+
+
+def schedule_bm25_refresh(app: FastAPI) -> None:
+    """Schedule a delayed BM25 corpus refresh, replacing any pending refresh."""
+    existing_timer = getattr(app.state, "bm25_refresh_timer", None)
+    if existing_timer is not None:
+        existing_timer.cancel()
+
+    timer = Timer(app.state.config.bm25_refresh_delay_seconds, refresh_bm25_for_app, args=(app,))
+    timer.daemon = True
+    timer.start()
+    app.state.bm25_refresh_timer = timer
+    logger.info(
+        "ebook_bm25_refresh_scheduled delay_seconds=%s",
+        app.state.config.bm25_refresh_delay_seconds,
+    )
+
+
+def cancel_bm25_refresh(app: FastAPI) -> None:
+    """Cancel any pending BM25 corpus refresh."""
+    existing_timer = getattr(app.state, "bm25_refresh_timer", None)
+    if existing_timer is not None:
+        existing_timer.cancel()
+        app.state.bm25_refresh_timer = None
+        logger.info("ebook_bm25_refresh_cancelled")
+
+
+def refresh_bm25_for_app(app: FastAPI) -> None:
+    """Refresh the BM25 corpus using the app engine and config."""
+    try:
+        refresh_bm25_for_engine(app.state.engine, app.state.config)
+    except Exception:
+        logger.exception("ebook_bm25_refresh_failed")
+
+
+def refresh_bm25_for_engine(engine: Engine, config: EbookSearchConfig) -> None:
+    """Refresh the BM25 corpus using a SQLAlchemy engine."""
+    with Session(engine) as session:
+        refresh_bm25_corpus(session, config)
diff --git a/python/ebook_search/api/main.py b/python/ebook_search/api/main.py
new file mode 100644
index 0000000..9be6d99
--- /dev/null
+++ b/python/ebook_search/api/main.py
@@ -0,0 +1,75 @@
+"""FastAPI HTMX app for EPUB search."""
+
+from __future__ import annotations
+
+import logging
+from contextlib import asynccontextmanager
+from typing import TYPE_CHECKING, Annotated
+
+import typer
+import uvicorn
+from fastapi import FastAPI
+from fastapi.staticfiles import StaticFiles
+from sqlalchemy.orm import Session
+
+from python.common import configure_logger
+from python.ebook_search.api.bm25_tasks import cancel_bm25_refresh
+from python.ebook_search.api.routes import register_admin_routes, register_page_routes, register_search_routes
+from python.ebook_search.api.web import STATIC_DIR
+from python.ebook_search.bm25_corpus import ensure_bm25_corpus
+from python.ebook_search.config import load_config
+from python.orm.common import get_postgres_engine
+
+if TYPE_CHECKING:
+    from collections.abc import AsyncIterator
+
+
+logger = logging.getLogger(__name__)
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI) -> AsyncIterator[None]:
+    """Manage application startup and shutdown resources."""
+    logger.info("ebook_search_startup")
+    app.state.engine = get_postgres_engine(name="RICHIE")
+    with Session(app.state.engine) as session:
+        ensure_bm25_corpus(session, app.state.config)
+    try:
+        yield
+    finally:
+        logger.info("ebook_search_shutdown")
+        cancel_bm25_refresh(app)
+        app.state.engine.dispose()
+
+
+def create_app() -> FastAPI:
+    """Create the EPUB search web app."""
+    app = FastAPI(title="EPUB Search", lifespan=lifespan)
+    app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")
+    app.state.config = load_config()
+    logger.info(
+        "ebook_search_config_loaded top_k=%s embedding_model=%s rerank_enabled=%s answer_enabled=%s library_paths=%s",
+        app.state.config.top_k,
+        app.state.config.embedding_model,
+        app.state.config.rerank.enabled,
+        app.state.config.answer_enabled,
+        len(app.state.config.library_paths),
+    )
+    register_page_routes(app)
+    register_search_routes(app)
+    register_admin_routes(app)
+    return app
+
+
+def serve(
+    host: Annotated[str, typer.Option("--host", "-h", help="Host to bind to")] = "127.0.0.1",
+    port: Annotated[int, typer.Option("--port", "-p", help="Port to bind to")] = 8070,
+    log_level: Annotated[str, typer.Option("--log-level", "-l", help="Log level")] = "INFO",
+) -> None:
+    """Start the EPUB search server."""
+    configure_logger(log_level)
+    uvicorn.run(create_app(), host=host, port=port)
+
+
+if __name__ == "__main__":
+    typer.run(serve)
diff --git a/python/ebook_search/api/routes/__init__.py b/python/ebook_search/api/routes/__init__.py
new file mode 100644
index 0000000..a6e49ca
--- /dev/null
+++ b/python/ebook_search/api/routes/__init__.py
@@ -0,0 +1,16 @@
+"""EPUB search web route modules."""
+
+from python.ebook_search.api.routes import admin, page, search
+
+register_admin_routes = admin.register_admin_routes
+register_page_routes = page.register_page_routes
+register_search_routes = search.register_search_routes
+
+__all__ = [
+    "admin",
+    "page",
+    "register_admin_routes",
+    "register_page_routes",
+    "register_search_routes",
+    "search",
+]
diff --git a/python/ebook_search/api/routes/admin.py b/python/ebook_search/api/routes/admin.py
new file mode 100644
index 0000000..ff83239
--- /dev/null
+++ b/python/ebook_search/api/routes/admin.py
@@ -0,0 +1,116 @@
+"""Admin routes for the EPUB search web UI."""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import replace
+from typing import TYPE_CHECKING
+
+from fastapi import APIRouter, Request
+from fastapi.responses import HTMLResponse
+from sqlalchemy.orm import Session
+
+from python.ebook_search.api.bm25_tasks import schedule_bm25_refresh
+from python.ebook_search.api.web import templates
+from python.ebook_search.embeddings import embed_missing_chunks, embedding_model_stats
+from python.ebook_search.ingest import ingest_configured_paths
+
+if TYPE_CHECKING:
+    from fastapi import FastAPI
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/admin")
+EMBED_ALL_BATCH_SIZE = 32
+
+
+def register_admin_routes(app: FastAPI) -> None:
+    """Register admin routes on the app."""
+    app.include_router(router)
+
+
+@router.get("", response_class=HTMLResponse)
+def admin(request: Request) -> HTMLResponse:
+    """Render the admin page."""
+    with Session(request.app.state.engine) as session:
+        stats = embedding_model_stats(session)
+    logger.info("ebook_admin_page_loaded models=%s", len(stats))
+    return templates.TemplateResponse(request, "admin.html", {"config": request.app.state.config, "stats": stats})
+
+
+@router.post("/scan", response_class=HTMLResponse)
+def scan_library(request: Request) -> HTMLResponse:
+    """Scan configured library paths for EPUB changes."""
+    try:
+        with Session(request.app.state.engine) as session:
+            count = ingest_configured_paths(session, request.app.state.config)
+            session.commit()
+    except Exception as error:
+        logger.exception("ebook_admin_scan_failed")
+        return templates.TemplateResponse(request, "partials/error.html", {"message": str(error)}, status_code=500)
+
+    logger.info("ebook_admin_scan_complete changed_files=%s", count)
+    if count > 0:
+        schedule_bm25_refresh(request.app)
+    return templates.TemplateResponse(request, "partials/admin_status.html", {"message": f"Indexed {count} EPUBs"})
+
+
+@router.post("/embed-missing", response_class=HTMLResponse)
+def embed_missing(request: Request) -> HTMLResponse:
+    """Embed chunks missing vectors for the configured model."""
+    try:
+        with Session(request.app.state.engine) as session:
+            count = embed_missing_chunks(session, request.app.state.config)
+            session.commit()
+    except Exception as error:
+        logger.exception("ebook_admin_embed_missing_failed")
+        return templates.TemplateResponse(request, "partials/error.html", {"message": str(error)}, status_code=500)
+
+    logger.info("ebook_admin_embed_missing_complete chunks=%s", count)
+    return templates.TemplateResponse(
+        request,
+        "partials/admin_status.html",
+        {"message": f"Embedded {count} chunks"},
+    )
+
+
+@router.post("/embed-all", response_class=HTMLResponse)
+def embed_all(request: Request) -> HTMLResponse:
+    """Embed all chunks missing vectors in fixed-size batches."""
+    total = 0
+    batches = 0
+    config = replace(request.app.state.config, embedding_batch_size=EMBED_ALL_BATCH_SIZE)
+    try:
+        with Session(request.app.state.engine) as session:
+            while True:
+                count = embed_missing_chunks(session, config)
+                if count == 0:
+                    break
+                session.commit()
+                total += count
+                batches += 1
+                logger.info(
+                    "ebook_admin_embed_all_batch_complete batch=%s chunks=%s total_chunks=%s",
+                    batches,
+                    count,
+                    total,
+                )
+    except Exception as error:
+        logger.exception(
+            "ebook_admin_embed_all_failed batches=%s chunks=%s",
+            batches,
+            total,
+        )
+        return templates.TemplateResponse(
+            request,
+            "partials/error.html",
+            {"message": f"Embed all failed after {total} chunks in {batches} batches: {error}"},
+            status_code=500,
+        )
+
+    logger.info("ebook_admin_embed_all_complete batches=%s chunks=%s", batches, total)
+    return templates.TemplateResponse(
+        request,
+        "partials/admin_status.html",
+        {"message": f"Embedded {total} chunks in {batches} batches of {EMBED_ALL_BATCH_SIZE}"},
+    )
diff --git a/python/ebook_search/api/routes/page.py b/python/ebook_search/api/routes/page.py
new file mode 100644
index 0000000..8e48867
--- /dev/null
+++ b/python/ebook_search/api/routes/page.py
@@ -0,0 +1,66 @@
+"""Page routes for the EPUB search web UI."""
+
+from __future__ import annotations
+
+import logging
+from typing import TYPE_CHECKING
+
+from fastapi import APIRouter, Request
+from fastapi.responses import HTMLResponse
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from python.ebook_search.api.web import templates
+from python.orm.richie import EbookSource
+
+if TYPE_CHECKING:
+    from fastapi import FastAPI
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+def register_page_routes(app: FastAPI) -> None:
+    """Register page routes on the app."""
+    app.include_router(router)
+
+
+@router.get("/", response_class=HTMLResponse)
+def index(request: Request) -> HTMLResponse:
+    """Render the search page."""
+    return templates.TemplateResponse(request, "search.html", {"config": request.app.state.config})
+
+
+@router.get("/books", response_class=HTMLResponse)
+def books(request: Request) -> HTMLResponse:
+    """Render the indexed books page."""
+    with Session(request.app.state.engine) as session:
+        sources = list(session.scalars(select(EbookSource).order_by(EbookSource.title)).all())
+    logger.info("ebook_books_page_loaded count=%s", len(sources))
+    return templates.TemplateResponse(request, "books.html", {"sources": sources})
+
+
+@router.get("/books/{source_id}", response_class=HTMLResponse)
+def book_detail(source_id: int, request: Request) -> HTMLResponse:
+    """Render details for one indexed book."""
+    with Session(request.app.state.engine) as session:
+        source = session.get(EbookSource, source_id)
+        if source is not None:
+            chapter_count = len(source.chapters)
+            chunk_count = len(source.chunks)
+        else:
+            chapter_count = 0
+            chunk_count = 0
+    logger.info(
+        "ebook_book_detail_loaded source_id=%s found=%s chapters=%s chunks=%s",
+        source_id,
+        source is not None,
+        chapter_count,
+        chunk_count,
+    )
+    return templates.TemplateResponse(
+        request,
+        "book_detail.html",
+        {"chapter_count": chapter_count, "chunk_count": chunk_count, "source": source},
+    )
diff --git a/python/ebook_search/api/routes/search.py b/python/ebook_search/api/routes/search.py
new file mode 100644
index 0000000..77ed022
--- /dev/null
+++ b/python/ebook_search/api/routes/search.py
@@ -0,0 +1,66 @@
+"""Search routes for the EPUB search web UI."""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import replace
+from time import perf_counter
+from typing import TYPE_CHECKING, Annotated
+
+from fastapi import APIRouter, Form, Request
+from fastapi.responses import HTMLResponse
+
+from python.ebook_search.answer import answer_query
+from python.ebook_search.api.web import templates
+from python.ebook_search.search import search_ebooks
+from python.ebook_search.timing import runtime_step_from_start
+
+if TYPE_CHECKING:
+    from fastapi import FastAPI
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+def register_search_routes(app: FastAPI) -> None:
+    """Register search routes on the app."""
+    app.include_router(router)
+
+
+@router.post("/search", response_class=HTMLResponse)
+def search(
+    request: Request,
+    query: Annotated[str, Form()],
+    rerank: Annotated[str | None, Form()] = None,
+) -> HTMLResponse:
+    """Run a search and render HTMX results."""
+    try:
+        response = search_ebooks(request.app.state.engine, query, request.app.state.config, rerank=rerank == "true")
+    except Exception as error:
+        logger.exception("ebook_search_request_failed")
+        return templates.TemplateResponse(request, "partials/error.html", {"message": str(error)}, status_code=500)
+
+    answer_start = perf_counter()
+    if request.app.state.config.answer_enabled:
+        try:
+            answer = answer_query(query, response.results, request.app.state.config)
+        except RuntimeError as error:
+            logger.warning("ebook_answer_request_failed_falling_back error=%s", error)
+            answer = "Answer generation failed. Source chunks are still shown below."
+    else:
+        logger.info("ebook_answer_skipped_disabled")
+        answer = "Answer generation is disabled. Source chunks are shown below."
+    answer_step_name = "Answer generation" if request.app.state.config.answer_enabled else "Answer skipped"
+    response = replace(
+        response,
+        timings=(*response.timings, runtime_step_from_start(answer_step_name, answer_start)),
+    )
+
+    logger.info(
+        "ebook_search_request_complete results=%s rank_label=%s runtime_ms=%.1f",
+        len(response.results),
+        response.rank_label,
+        response.total_runtime_ms,
+    )
+    return templates.TemplateResponse(request, "partials/results.html", {"answer": answer, "response": response})
diff --git a/python/ebook_search/api/static/style.css b/python/ebook_search/api/static/style.css
new file mode 100644
index 0000000..c869d55
--- /dev/null
+++ b/python/ebook_search/api/static/style.css
@@ -0,0 +1,140 @@
+body {
+    margin: 0;
+    background: #f7f7f4;
+    color: #202124;
+    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+}
+
+main {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 24px;
+}
+
+nav {
+    display: flex;
+    gap: 12px;
+    align-items: center;
+    margin-bottom: 20px;
+}
+
+nav form {
+    margin: 0;
+}
+
+.actions {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 12px;
+    margin-bottom: 24px;
+}
+
+textarea {
+    display: block;
+    width: 100%;
+    margin: 8px 0 12px;
+}
+
+button {
+    padding: 8px 14px;
+}
+
+.check {
+    display: inline-flex;
+    gap: 8px;
+    align-items: center;
+    margin-right: 12px;
+}
+
+.rank-label {
+    margin-top: 24px;
+    font-weight: 700;
+}
+
+.results {
+    padding-left: 24px;
+}
+
+.meta,
+.scores,
+.status {
+    color: #626a73;
+}
+
+.scores {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin: 12px 0;
+}
+
+.scores div {
+    display: inline-flex;
+    gap: 4px;
+    align-items: baseline;
+}
+
+.scores dt {
+    font-weight: 700;
+}
+
+.scores dd {
+    margin: 0;
+}
+
+.runtime {
+    margin-top: 16px;
+}
+
+.timing-chart {
+    display: grid;
+    gap: 8px;
+    padding: 0;
+    list-style: none;
+}
+
+.timing-chart li {
+    display: grid;
+    grid-template-columns: minmax(150px, 1fr) minmax(160px, 2fr) auto auto;
+    gap: 8px;
+    align-items: center;
+}
+
+.timing-bar {
+    height: 10px;
+    overflow: hidden;
+    background: #e5e5df;
+}
+
+.timing-bar span {
+    display: block;
+    height: 100%;
+    background: #3767c8;
+}
+
+.timing-value,
+.timing-remaining {
+    color: #626a73;
+    font-variant-numeric: tabular-nums;
+}
+
+table {
+    width: 100%;
+    border-collapse: collapse;
+}
+
+th,
+td {
+    padding: 8px;
+    border-bottom: 1px solid #d8d8d2;
+    text-align: left;
+}
+
+th {
+    font-weight: 700;
+}
+
+.error {
+    color: #9f1d20;
+    font-weight: 700;
+}
diff --git a/python/ebook_search/api/templates/admin.html b/python/ebook_search/api/templates/admin.html
new file mode 100644
index 0000000..12e588e
--- /dev/null
+++ b/python/ebook_search/api/templates/admin.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EPUB Admin</title>
+    <script src="https://unpkg.com/htmx.org@2.0.4"></script>
+    <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+    <main>
+        <nav>
+            <a href="/">Search</a>
+            <a href="/books">Books</a>
+            <a href="/admin">Admin</a>
+        </nav>
+        <h1>Admin</h1>
+        <section id="admin-status"></section>
+        <section class="actions">
+            <form hx-post="/admin/scan" hx-target="#admin-status" hx-swap="innerHTML">
+                <button type="submit">Scan</button>
+            </form>
+            <form hx-post="/admin/embed-missing" hx-target="#admin-status" hx-swap="innerHTML">
+                <button type="submit">Embed</button>
+            </form>
+            <form hx-post="/admin/embed-all" hx-target="#admin-status" hx-swap="innerHTML">
+                <button type="submit">Embed all</button>
+            </form>
+        </section>
+        <section>
+            <h2>Embeddings</h2>
+            <table>
+                <thead>
+                    <tr>
+                        <th>Model</th>
+                        <th>Dimensions</th>
+                        <th>Embedded</th>
+                        <th>Missing</th>
+                        <th>Total chunks</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {% for item in stats %}
+                        <tr>
+                            <td>{{ item.model_name }}</td>
+                            <td>{{ item.dimension }}</td>
+                            <td>{{ item.embedded_chunks }}</td>
+                            <td>{{ item.missing_chunks }}</td>
+                            <td>{{ item.total_chunks }}</td>
+                        </tr>
+                    {% endfor %}
+                </tbody>
+            </table>
+        </section>
+    </main>
+</body>
+</html>
diff --git a/python/ebook_search/api/templates/book_detail.html b/python/ebook_search/api/templates/book_detail.html
new file mode 100644
index 0000000..735aeaf
--- /dev/null
+++ b/python/ebook_search/api/templates/book_detail.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>{% if source %}{{ source.title }}{% else %}Book not found{% endif %}</title>
+    <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+    <main>
+        <nav>
+            <a href="/">Search</a>
+            <a href="/books">Books</a>
+            <a href="/admin">Admin</a>
+        </nav>
+        {% if source %}
+            <h1>{{ source.title }}</h1>
+            <p class="meta">{{ source.author or "Unknown author" }}</p>
+            <dl>
+                <dt>File</dt>
+                <dd>{{ source.file_path }}</dd>
+                <dt>Chapters</dt>
+                <dd>{{ chapter_count }}</dd>
+                <dt>Chunks</dt>
+                <dd>{{ chunk_count }}</dd>
+            </dl>
+        {% else %}
+            <h1>Book not found</h1>
+        {% endif %}
+    </main>
+</body>
+</html>
diff --git a/python/ebook_search/api/templates/books.html b/python/ebook_search/api/templates/books.html
new file mode 100644
index 0000000..c7bc487
--- /dev/null
+++ b/python/ebook_search/api/templates/books.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EPUB Books</title>
+    <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+    <main>
+        <nav>
+            <a href="/">Search</a>
+            <a href="/books">Books</a>
+            <a href="/admin">Admin</a>
+        </nav>
+        <h1>Books</h1>
+        {% if sources %}
+            <ol class="results">
+                {% for source in sources %}
+                    <li>
+                        <h2><a href="/books/{{ source.id }}">{{ source.title }}</a></h2>
+                        <p class="meta">{{ source.author or "Unknown author" }}</p>
+                    </li>
+                {% endfor %}
+            </ol>
+        {% else %}
+            <p>No EPUBs indexed.</p>
+        {% endif %}
+    </main>
+</body>
+</html>
diff --git a/python/ebook_search/api/templates/partials/admin_status.html b/python/ebook_search/api/templates/partials/admin_status.html
new file mode 100644
index 0000000..f8fa12f
--- /dev/null
+++ b/python/ebook_search/api/templates/partials/admin_status.html
@@ -0,0 +1 @@
+<p class="status">{{ message }}</p>
diff --git a/python/ebook_search/api/templates/partials/error.html b/python/ebook_search/api/templates/partials/error.html
new file mode 100644
index 0000000..9657121
--- /dev/null
+++ b/python/ebook_search/api/templates/partials/error.html
@@ -0,0 +1 @@
+<p class="error">{{ message }}</p>
diff --git a/python/ebook_search/api/templates/partials/results.html b/python/ebook_search/api/templates/partials/results.html
new file mode 100644
index 0000000..bc29eec
--- /dev/null
+++ b/python/ebook_search/api/templates/partials/results.html
@@ -0,0 +1,74 @@
+<div class="rank-label">{{ response.rank_label }}</div>
+{% if response.timings %}
+    <section class="runtime">
+        <h2>Runtime</h2>
+        <p class="meta">Total {{ "%.1f"|format(response.total_runtime_ms) }} ms</p>
+        <ol class="timing-chart">
+            {% set total = response.total_runtime_ms %}
+            {% set ns = namespace(remaining=total) %}
+            {% for step in response.timings %}
+                {% set width = (step.duration_ms / total * 100) if total else 0 %}
+                {% if step.counts_toward_total %}
+                    {% set ns.remaining = ns.remaining - step.duration_ms %}
+                {% endif %}
+                <li>
+                    <span class="timing-label">{{ step.name }}</span>
+                    <span class="timing-bar"><span style="width: {{ "%.2f"|format(width) }}%"></span></span>
+                    <span class="timing-value">{{ "%.1f"|format(step.duration_ms) }} ms</span>
+                    <span class="timing-remaining">{{ "%.1f"|format([ns.remaining, 0]|max) }} ms left</span>
+                </li>
+            {% endfor %}
+        </ol>
+    </section>
+{% endif %}
+<section class="answer">
+    <h2>Answer</h2>
+    <p>{{ answer }}</p>
+</section>
+{% if response.results %}
+    <ol class="results">
+        {% for result in response.results %}
+            <li>
+                <h2>{{ result.source_title }}</h2>
+                <p class="meta">
+                    {% if result.source_author %}{{ result.source_author }}{% endif %}
+                    {% if result.chapter_title %} · {{ result.chapter_title }}{% endif %}
+                    {% if result.page_label %} · page {{ result.page_label }}{% endif %}
+                </p>
+                <p>{{ result.text }}</p>
+                <dl class="scores">
+                    <div>
+                        <dt>final</dt>
+                        <dd>{{ "%.3f"|format(result.score) }}</dd>
+                    </div>
+                    {% if result.rerank_score is not none %}
+                        <div>
+                            <dt>rerank</dt>
+                            <dd>{{ "%.3f"|format(result.rerank_score) }}</dd>
+                        </div>
+                    {% endif %}
+                    {% if result.vector_score is not none %}
+                        <div>
+                            <dt>vector cosine</dt>
+                            <dd>{{ "%.3f"|format(result.vector_score) }}</dd>
+                        </div>
+                    {% endif %}
+                    {% if result.bm25_score is not none %}
+                        <div>
+                            <dt>BM25</dt>
+                            <dd>{{ "%.6f"|format(result.bm25_score) }}</dd>
+                        </div>
+                    {% endif %}
+                    {% if result.fused_score is not none %}
+                        <div>
+                            <dt>RRF</dt>
+                            <dd>{{ "%.3f"|format(result.fused_score) }}</dd>
+                        </div>
+                    {% endif %}
+                </dl>
+            </li>
+        {% endfor %}
+    </ol>
+{% else %}
+    <p>No results.</p>
+{% endif %}
diff --git a/python/ebook_search/api/templates/search.html b/python/ebook_search/api/templates/search.html
new file mode 100644
index 0000000..df566c5
--- /dev/null
+++ b/python/ebook_search/api/templates/search.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EPUB Search</title>
+    <script src="https://unpkg.com/htmx.org@2.0.4"></script>
+    <link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+    <main>
+        <nav>
+            <a href="/">Search</a>
+            <a href="/books">Books</a>
+            <a href="/admin">Admin</a>
+        </nav>
+        <h1>EPUB Search</h1>
+        <form hx-post="/search" hx-target="#results" hx-swap="innerHTML">
+            <label for="query">Search</label>
+            <textarea id="query" name="query" rows="4" required></textarea>
+            <label class="check">
+                <input type="checkbox" name="rerank" value="true" {% if config.rerank.enabled %}checked{% endif %}>
+                Rerank
+            </label>
+            <button type="submit">Search</button>
+        </form>
+        <section id="results"></section>
+    </main>
+</body>
+</html>
diff --git a/python/ebook_search/api/web.py b/python/ebook_search/api/web.py
new file mode 100644
index 0000000..85f6128
--- /dev/null
+++ b/python/ebook_search/api/web.py
@@ -0,0 +1,13 @@
+"""Shared web UI resources for EPUB search."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from fastapi.templating import Jinja2Templates
+
+PACKAGE_DIR = Path(__file__).resolve().parent
+TEMPLATE_DIR = PACKAGE_DIR / "templates"
+STATIC_DIR = PACKAGE_DIR / "static"
+
+templates = Jinja2Templates(directory=TEMPLATE_DIR)