transcript gutter

CHANGELOG.md

@@ -1,12 +1,5 @@
 # Changelog
 
-## [0.28.0](https://github.com/Monadical-SAS/reflector/compare/v0.27.0...v0.28.0) (2026-01-20)
-
-
-### Features
-
-* worker affinity ([#819](https://github.com/Monadical-SAS/reflector/issues/819)) ([3b6540e](https://github.com/Monadical-SAS/reflector/commit/3b6540eae5b597449f98661bdf15483b77be3268))
-
 ## [0.27.0](https://github.com/Monadical-SAS/reflector/compare/v0.26.0...v0.27.0) (2025-12-26)
 
 

docker-compose.yml

@@ -34,7 +34,7 @@ services:
     environment:
       ENTRYPOINT: beat
 
-  hatchet-worker-cpu:
+  hatchet-worker:
     build:
       context: server
     volumes:
@@ -43,20 +43,7 @@ services:
     env_file:
       - ./server/.env
     environment:
-      ENTRYPOINT: hatchet-worker-cpu
-    depends_on:
-      hatchet:
-        condition: service_healthy
-  hatchet-worker-llm:
-    build:
-      context: server
-    volumes:
-      - ./server/:/app/
-      - /app/.venv
-    env_file:
-      - ./server/.env
-    environment:
-      ENTRYPOINT: hatchet-worker-llm
+      ENTRYPOINT: hatchet-worker
     depends_on:
       hatchet:
         condition: service_healthy

server/reflector/hatchet/run_workers.py

@@ -0,0 +1,77 @@
+"""
+Run Hatchet workers for the multitrack pipeline.
+Runs as a separate process, just like Celery workers.
+
+Usage:
+    uv run -m reflector.hatchet.run_workers
+
+    # Or via docker:
+    docker compose exec server uv run -m reflector.hatchet.run_workers
+"""
+
+import signal
+import sys
+
+from hatchet_sdk.rate_limit import RateLimitDuration
+
+from reflector.hatchet.constants import LLM_RATE_LIMIT_KEY, LLM_RATE_LIMIT_PER_SECOND
+from reflector.logger import logger
+from reflector.settings import settings
+
+
+def main() -> None:
+    """Start Hatchet worker polling."""
+    if not settings.HATCHET_ENABLED:
+        logger.error("HATCHET_ENABLED is False, not starting workers")
+        sys.exit(1)
+
+    if not settings.HATCHET_CLIENT_TOKEN:
+        logger.error("HATCHET_CLIENT_TOKEN is not set")
+        sys.exit(1)
+
+    logger.info(
+        "Starting Hatchet workers",
+        debug=settings.HATCHET_DEBUG,
+    )
+
+    # Import here (not top-level) - workflow modules call HatchetClientManager.get_client()
+    # at module level because Hatchet SDK decorators (@workflow.task) bind at import time.
+    # Can't use lazy init: decorators need the client object when function is defined.
+    from reflector.hatchet.client import HatchetClientManager  # noqa: PLC0415
+    from reflector.hatchet.workflows import (  # noqa: PLC0415
+        daily_multitrack_pipeline,
+        subject_workflow,
+        topic_chunk_workflow,
+        track_workflow,
+    )
+
+    hatchet = HatchetClientManager.get_client()
+
+    hatchet.rate_limits.put(
+        LLM_RATE_LIMIT_KEY, LLM_RATE_LIMIT_PER_SECOND, RateLimitDuration.SECOND
+    )
+
+    worker = hatchet.worker(
+        "reflector-pipeline-worker",
+        workflows=[
+            daily_multitrack_pipeline,
+            subject_workflow,
+            topic_chunk_workflow,
+            track_workflow,
+        ],
+    )
+
+    def shutdown_handler(signum: int, frame) -> None:
+        logger.info("Received shutdown signal, stopping workers...")
+        # Worker cleanup happens automatically on exit
+        sys.exit(0)
+
+    signal.signal(signal.SIGINT, shutdown_handler)
+    signal.signal(signal.SIGTERM, shutdown_handler)
+
+    logger.info("Starting Hatchet worker polling...")
+    worker.start()
+
+
+if __name__ == "__main__":
+    main()

server/reflector/hatchet/run_workers_cpu.py

@@ -1,48 +0,0 @@
-"""
-CPU-heavy worker pool for audio processing tasks.
-Handles ONLY: mixdown_tracks
-
-Configuration:
-- slots=1: Only mixdown (already serialized globally with max_runs=1)
-- Worker affinity: pool=cpu-heavy
-"""
-
-from reflector.hatchet.client import HatchetClientManager
-from reflector.hatchet.workflows.daily_multitrack_pipeline import (
-    daily_multitrack_pipeline,
-)
-from reflector.logger import logger
-from reflector.settings import settings
-
-
-def main():
-    if not settings.HATCHET_ENABLED:
-        logger.error("HATCHET_ENABLED is False, not starting CPU workers")
-        return
-
-    hatchet = HatchetClientManager.get_client()
-
-    logger.info(
-        "Starting Hatchet CPU worker pool (mixdown only)",
-        worker_name="cpu-worker-pool",
-        slots=1,
-        labels={"pool": "cpu-heavy"},
-    )
-
-    cpu_worker = hatchet.worker(
-        "cpu-worker-pool",
-        slots=1,  # Only 1 mixdown at a time (already serialized globally)
-        labels={
-            "pool": "cpu-heavy",
-        },
-        workflows=[daily_multitrack_pipeline],
-    )
-
-    try:
-        cpu_worker.start()
-    except KeyboardInterrupt:
-        logger.info("Received shutdown signal, stopping CPU workers...")
-
-
-if __name__ == "__main__":
-    main()

server/reflector/hatchet/run_workers_llm.py

@@ -1,56 +0,0 @@
-"""
-LLM/I/O worker pool for all non-CPU tasks.
-Handles: all tasks except mixdown_tracks (transcription, LLM inference, orchestration)
-"""
-
-from reflector.hatchet.client import HatchetClientManager
-from reflector.hatchet.workflows.daily_multitrack_pipeline import (
-    daily_multitrack_pipeline,
-)
-from reflector.hatchet.workflows.subject_processing import subject_workflow
-from reflector.hatchet.workflows.topic_chunk_processing import topic_chunk_workflow
-from reflector.hatchet.workflows.track_processing import track_workflow
-from reflector.logger import logger
-from reflector.settings import settings
-
-SLOTS = 10
-WORKER_NAME = "llm-worker-pool"
-POOL = "llm-io"
-
-
-def main():
-    if not settings.HATCHET_ENABLED:
-        logger.error("HATCHET_ENABLED is False, not starting LLM workers")
-        return
-
-    hatchet = HatchetClientManager.get_client()
-
-    logger.info(
-        "Starting Hatchet LLM worker pool (all tasks except mixdown)",
-        worker_name=WORKER_NAME,
-        slots=SLOTS,
-        labels={"pool": POOL},
-    )
-
-    llm_worker = hatchet.worker(
-        WORKER_NAME,
-        slots=SLOTS,  # not all slots are probably used
-        labels={
-            "pool": POOL,
-        },
-        workflows=[
-            daily_multitrack_pipeline,
-            topic_chunk_workflow,
-            subject_workflow,
-            track_workflow,
-        ],
-    )
-
-    try:
-        llm_worker.start()
-    except KeyboardInterrupt:
-        logger.info("Received shutdown signal, stopping LLM workers...")
-
-
-if __name__ == "__main__":
-    main()

server/reflector/hatchet/workflows/daily_multitrack_pipeline.py

@@ -23,12 +23,7 @@ from pathlib import Path
 from typing import Any, Callable, Coroutine, Protocol, TypeVar
 
 import httpx
-from hatchet_sdk import (
-    ConcurrencyExpression,
-    ConcurrencyLimitStrategy,
-    Context,
-)
-from hatchet_sdk.labels import DesiredWorkerLabel
+from hatchet_sdk import Context
 from pydantic import BaseModel
 
 from reflector.dailyco_api.client import DailyApiClient
@@ -472,20 +467,6 @@ async def process_tracks(input: PipelineInput, ctx: Context) -> ProcessTracksRes
     parents=[process_tracks],
     execution_timeout=timedelta(seconds=TIMEOUT_AUDIO),
     retries=3,
-    desired_worker_labels={
-        "pool": DesiredWorkerLabel(
-            value="cpu-heavy",
-            required=True,
-            weight=100,
-        ),
-    },
-    concurrency=[
-        ConcurrencyExpression(
-            expression="'mixdown-global'",
-            max_runs=1,  # serialize mixdown to prevent resource contention
-            limit_strategy=ConcurrencyLimitStrategy.GROUP_ROUND_ROBIN,  # Queue
-        )
-    ],
 )
 @with_error_handling(TaskName.MIXDOWN_TRACKS)
 async def mixdown_tracks(input: PipelineInput, ctx: Context) -> MixdownResult:

server/reflector/hatchet/workflows/topic_chunk_processing.py

@@ -7,11 +7,7 @@ Spawned dynamically by detect_topics via aio_run_many() for parallel processing.
 
 from datetime import timedelta
 
-from hatchet_sdk import (
-    ConcurrencyExpression,
-    ConcurrencyLimitStrategy,
-    Context,
-)
+from hatchet_sdk import ConcurrencyExpression, ConcurrencyLimitStrategy, Context
 from hatchet_sdk.rate_limit import RateLimit
 from pydantic import BaseModel
 
@@ -38,13 +34,11 @@ hatchet = HatchetClientManager.get_client()
 topic_chunk_workflow = hatchet.workflow(
     name="TopicChunkProcessing",
     input_validator=TopicChunkInput,
-    concurrency=[
-        ConcurrencyExpression(
-            expression="'global'",  # constant string = global limit across all runs
-            max_runs=20,
-            limit_strategy=ConcurrencyLimitStrategy.GROUP_ROUND_ROBIN,
-        )
-    ],
+    concurrency=ConcurrencyExpression(
+        expression="'global'",  # constant string = global limit across all runs
+        max_runs=20,
+        limit_strategy=ConcurrencyLimitStrategy.GROUP_ROUND_ROBIN,
+    ),
 )
 
 

server/runserver.sh

@@ -7,10 +7,8 @@ elif [ "${ENTRYPOINT}" = "worker" ]; then
     uv run celery -A reflector.worker.app worker --loglevel=info
 elif [ "${ENTRYPOINT}" = "beat" ]; then
     uv run celery -A reflector.worker.app beat --loglevel=info
-elif [ "${ENTRYPOINT}" = "hatchet-worker-cpu" ]; then
-    uv run python -m reflector.hatchet.run_workers_cpu
-elif [ "${ENTRYPOINT}" = "hatchet-worker-llm" ]; then
-    uv run python -m reflector.hatchet.run_workers_llm
+elif [ "${ENTRYPOINT}" = "hatchet-worker" ]; then
+    uv run python -m reflector.hatchet.run_workers
 else
     echo "Unknown command"
 fi

www/app/(app)/transcripts/[transcriptId]/_components/TopicList.tsx

@@ -1,12 +1,12 @@
 import React, { useState, useEffect } from "react";
 import ScrollToBottom from "../../scrollToBottom";
 import { Topic } from "../../webSocketTypes";
-import useParticipants from "../../useParticipants";
-import { Box, Flex, Text, Accordion } from "@chakra-ui/react";
-import { TopicItem } from "./TopicItem";
+import { Box, Flex, Text } from "@chakra-ui/react";
+import { formatTime } from "../../../../lib/time";
+import { getTopicColor } from "../../../../lib/topicColors";
 import { TranscriptStatus } from "../../../../lib/transcript";
-
 import { featureEnabled } from "../../../../lib/features";
+import { TOPICS_SCROLL_DIV_ID } from "./constants";
 
 type TopicListProps = {
   topics: Topic[];
@@ -18,6 +18,7 @@ type TopicListProps = {
   transcriptId: string;
   status: TranscriptStatus | null;
   currentTranscriptText: any;
+  onTopicClick?: (topicId: string) => void;
 };
 
 export function TopicList({
@@ -27,30 +28,13 @@ export function TopicList({
   transcriptId,
   status,
   currentTranscriptText,
+  onTopicClick,
 }: TopicListProps) {
   const [activeTopic, setActiveTopic] = useActiveTopic;
+  const [hoveredTopicId, setHoveredTopicId] = useState<string | null>(null);
   const [autoscrollEnabled, setAutoscrollEnabled] = useState<boolean>(true);
-  const participants = useParticipants(transcriptId);
 
-  const scrollToTopic = () => {
-    const topicDiv = document.getElementById(`topic-${activeTopic?.id}`);
-
-    setTimeout(() => {
-      topicDiv?.scrollIntoView({
-        behavior: "smooth",
-        block: "start",
-        inline: "nearest",
-      });
-    }, 200);
-  };
-
-  useEffect(() => {
-    if (activeTopic && autoscroll) scrollToTopic();
-  }, [activeTopic, autoscroll]);
-
-  // scroll top is not rounded, heights are, so exact match won't work.
-  // https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollHeight#determine_if_an_element_has_been_totally_scrolled
-  const toggleScroll = (element) => {
+  const toggleScroll = (element: HTMLElement) => {
     const bottom =
       Math.abs(
         element.scrollHeight - element.clientHeight - element.scrollTop,
@@ -61,14 +45,19 @@ export function TopicList({
       setAutoscrollEnabled(true);
     }
   };
-  const handleScroll = (e) => {
-    toggleScroll(e.target);
+
+  const handleScroll = (e: React.UIEvent<HTMLDivElement>) => {
+    toggleScroll(e.target as HTMLElement);
+  };
+
+  const scrollToBottom = () => {
+    const topicsDiv = document.getElementById(TOPICS_SCROLL_DIV_ID);
+    if (topicsDiv) topicsDiv.scrollTop = topicsDiv.scrollHeight;
   };
 
   useEffect(() => {
     if (autoscroll) {
-      const topicsDiv = document.getElementById("scroll-div");
-
+      const topicsDiv = document.getElementById(TOPICS_SCROLL_DIV_ID);
       topicsDiv && toggleScroll(topicsDiv);
     }
   }, [activeTopic, autoscroll]);
@@ -77,37 +66,41 @@ export function TopicList({
     if (autoscroll && autoscrollEnabled) scrollToBottom();
   }, [topics.length, currentTranscriptText]);
 
-  const scrollToBottom = () => {
-    const topicsDiv = document.getElementById("scroll-div");
-
-    if (topicsDiv) topicsDiv.scrollTop = topicsDiv.scrollHeight;
-  };
-
-  const getSpeakerName = (speakerNumber: number) => {
-    if (!participants.response) return;
-    return (
-      participants.response.find(
-        (participant) => participant.speaker == speakerNumber,
-      )?.name || `Speaker ${speakerNumber}`
-    );
-  };
-
-  const requireLogin = featureEnabled("requireLogin");
-
   useEffect(() => {
     if (autoscroll) {
       setActiveTopic(topics[topics.length - 1]);
     }
   }, [topics, autoscroll]);
 
+  const handleTopicClick = (topic: Topic) => {
+    setActiveTopic(topic);
+    if (onTopicClick) {
+      onTopicClick(topic.id);
+    }
+  };
+
+  const handleTopicMouseEnter = (topic: Topic) => {
+    setHoveredTopicId(topic.id);
+    // If already active, toggle off when mousing over
+    if (activeTopic?.id === topic.id) {
+      setActiveTopic(null);
+    } else {
+      setActiveTopic(topic);
+    }
+  };
+
+  const handleTopicMouseLeave = () => {
+    setHoveredTopicId(null);
+  };
+
+  const requireLogin = featureEnabled("requireLogin");
+
   return (
     <Flex
-      position={"relative"}
-      w={"100%"}
-      h={"95%"}
-      flexDirection={"column"}
-      justify={"center"}
-      align={"center"}
+      position="relative"
+      w="full"
+      h="200px"
+      flexDirection="column"
       flexShrink={0}
     >
       {autoscroll && (
@@ -118,45 +111,71 @@ export function TopicList({
       )}
 
       <Box
-        id="scroll-div"
-        overflowY={"auto"}
-        h={"100%"}
+        id={TOPICS_SCROLL_DIV_ID}
+        overflowY="auto"
+        h="full"
         onScroll={handleScroll}
         width="full"
       >
         {topics.length > 0 && (
-          <Accordion.Root
-            multiple={false}
-            collapsible={true}
-            value={activeTopic ? [activeTopic.id] : []}
-            onValueChange={(details) => {
-              const selectedTopicId = details.value[0];
-              const selectedTopic = selectedTopicId
-                ? topics.find((t) => t.id === selectedTopicId)
-                : null;
-              setActiveTopic(selectedTopic || null);
-            }}
-          >
-            {topics.map((topic) => (
-              <TopicItem
-                key={topic.id}
-                topic={topic}
-                isActive={activeTopic?.id === topic.id}
-                getSpeakerName={getSpeakerName}
-              />
-            ))}
-          </Accordion.Root>
+          <Flex direction="column" gap={1} p={2}>
+            {topics.map((topic, index) => {
+              const color = getTopicColor(index);
+              const isActive = activeTopic?.id === topic.id;
+              const isHovered = hoveredTopicId === topic.id;
+
+              return (
+                <Flex
+                  key={topic.id}
+                  id={`topic-${topic.id}`}
+                  gap={2}
+                  align="center"
+                  py={1}
+                  px={2}
+                  cursor="pointer"
+                  bg={isActive || isHovered ? "gray.100" : "transparent"}
+                  _hover={{ bg: "gray.50" }}
+                  onClick={() => handleTopicClick(topic)}
+                  onMouseEnter={() => handleTopicMouseEnter(topic)}
+                  onMouseLeave={handleTopicMouseLeave}
+                >
+                  {/* Color indicator */}
+                  <Box
+                    w="12px"
+                    h="12px"
+                    borderRadius="full"
+                    bg={color}
+                    flexShrink={0}
+                  />
+
+                  {/* Topic title */}
+                  <Text
+                    flex={1}
+                    fontSize="sm"
+                    fontWeight={isActive ? "semibold" : "normal"}
+                  >
+                    {topic.title}
+                  </Text>
+
+                  {/* Timestamp */}
+                  <Text as="span" color="gray.500" fontSize="xs" flexShrink={0}>
+                    {formatTime(topic.timestamp)}
+                  </Text>
+                </Flex>
+              );
+            })}
+          </Flex>
         )}
 
         {status == "recording" && (
-          <Box textAlign={"center"}>
+          <Box textAlign="center">
             <Text>{currentTranscriptText}</Text>
           </Box>
         )}
         {(status == "recording" || status == "idle") &&
           currentTranscriptText.length == 0 &&
           topics.length == 0 && (
-            <Box textAlign={"center"} color="gray">
+            <Box textAlign="center" color="gray">
               <Text>
                 Full discussion transcript will appear here after you start
                 recording.
@@ -167,7 +186,7 @@ export function TopicList({
             </Box>
           )}
         {status == "processing" && (
-          <Box textAlign={"center"} color="gray">
+          <Box textAlign="center" color="gray">
             <Text>We are processing the recording, please wait.</Text>
             {!requireLogin && (
               <span>
@@ -177,12 +196,12 @@ export function TopicList({
           </Box>
         )}
         {status == "ended" && topics.length == 0 && (
-          <Box textAlign={"center"} color="gray">
+          <Box textAlign="center" color="gray">
             <Text>Recording has ended without topics being found.</Text>
           </Box>
         )}
         {status == "error" && (
-          <Box textAlign={"center"} color="gray">
+          <Box textAlign="center" color="gray">
             <Text>There was an error processing your recording</Text>
           </Box>
         )}

www/app/(app)/transcripts/[transcriptId]/_components/TranscriptWithGutter.tsx

@@ -0,0 +1,106 @@
+import { Box, Text, IconButton } from "@chakra-ui/react";
+import { ChevronUp } from "lucide-react";
+import { Topic } from "../../webSocketTypes";
+import { getTopicColor } from "../../../../lib/topicColors";
+import { TOPICS_SCROLL_DIV_ID } from "./constants";
+
+interface TranscriptWithGutterProps {
+  topics: Topic[];
+  getSpeakerName: (speakerNumber: number) => string | undefined;
+  onGutterClick: (topicId: string) => void;
+}
+
+export function TranscriptWithGutter({
+  topics,
+  getSpeakerName,
+  onGutterClick,
+}: TranscriptWithGutterProps) {
+  const scrollToTopics = () => {
+    // Scroll to the topic list at the top
+    const topicList = document.getElementById(TOPICS_SCROLL_DIV_ID);
+    if (topicList) {
+      topicList.scrollIntoView({
+        behavior: "smooth",
+        block: "start",
+      });
+    }
+  };
+
+  return (
+    <Box>
+      {topics.map((topic, topicIndex) => {
+        const color = getTopicColor(topicIndex);
+
+        return (
+          <Box key={topic.id} position="relative">
+            {/* Topic Header with Up Button */}
+            <Box
+              py={3}
+              px={4}
+              fontWeight="semibold"
+              fontSize="lg"
+              display="flex"
+              alignItems="center"
+              justifyContent="space-between"
+            >
+              <Text>{topic.title}</Text>
+              <IconButton
+                aria-label="Scroll to topics"
+                size="sm"
+                variant="ghost"
+                onClick={scrollToTopics}
+              >
+                <ChevronUp size={16} />
+              </IconButton>
+            </Box>
+
+            {/* Segments container with single gutter */}
+            <Box position="relative">
+              {/* Single continuous gutter for entire topic */}
+              <Box
+                className="topic-gutter"
+                position="absolute"
+                left={0}
+                top={0}
+                bottom={0}
+                width="4px"
+                bg={color}
+                cursor="pointer"
+                transition="all 0.2s"
+                _hover={{
+                  filter: "brightness(1.2)",
+                  width: "6px",
+                }}
+                onClick={() => onGutterClick(topic.id)}
+              />
+
+              {/* Segments */}
+              {topic.segments?.map((segment, segmentIndex) => (
+                <Box
+                  key={segmentIndex}
+                  id={`segment-${topic.id}-${segmentIndex}`}
+                  py={2}
+                  px={4}
+                  pl={12}
+                  _hover={{
+                    bg: "gray.50",
+                  }}
+                >
+                  {/* Segment Content */}
+                  <Text fontSize="sm">
+                    <Text as="span" fontWeight="semibold" color="gray.700">
+                      {getSpeakerName(segment.speaker) ||
+                        `Speaker ${segment.speaker}`}
+                      :
+                    </Text>{" "}
+                    {segment.text}
+                  </Text>
+                </Box>
+              ))}
+            </Box>
+          </Box>
+        );
+      })}
+    </Box>
+  );
+}

www/app/(app)/transcripts/[transcriptId]/_components/constants.ts

@@ -0,0 +1 @@
+export const TOPICS_SCROLL_DIV_ID = "topics-scroll-div";

www/app/(app)/transcripts/[transcriptId]/page.tsx

@@ -3,7 +3,9 @@ import Modal from "../modal";
 import useTopics from "../useTopics";
 import useWaveform from "../useWaveform";
 import useMp3 from "../useMp3";
+import useParticipants from "../useParticipants";
 import { TopicList } from "./_components/TopicList";
+import { TranscriptWithGutter } from "./_components/TranscriptWithGutter";
 import { Topic } from "../webSocketTypes";
 import React, { useEffect, useState, use } from "react";
 import FinalSummary from "./finalSummary";
@@ -45,14 +47,91 @@ export default function TranscriptDetails(details: TranscriptDetails) {
 
   const mp3 = useMp3(transcriptId, waiting);
   const topics = useTopics(transcriptId);
+  const participants = useParticipants(transcriptId);
   const waveform = useWaveform(
     transcriptId,
     waiting || mp3.audioDeleted === true,
   );
   const useActiveTopic = useState<Topic | null>(null);
+  const [activeTopic, setActiveTopic] = useActiveTopic;
   const [finalSummaryElement, setFinalSummaryElement] =
     useState<HTMLDivElement | null>(null);
 
+  // IntersectionObserver for active topic detection based on scroll position
+  useEffect(() => {
+    if (!topics.topics || topics.topics.length === 0) return;
+
+    const observer = new IntersectionObserver(
+      (entries) => {
+        // Find the most visible segment
+        let mostVisibleEntry: IntersectionObserverEntry | null = null;
+        let maxRatio = 0;
+
+        entries.forEach((entry) => {
+          if (entry.isIntersecting && entry.intersectionRatio > maxRatio) {
+            maxRatio = entry.intersectionRatio;
+            mostVisibleEntry = entry;
+          }
+        });
+
+        if (mostVisibleEntry) {
+          // Extract topicId from segment id (format: "segment-{topicId}-{idx}")
+          const segmentId = mostVisibleEntry.target.id;
+          const match = segmentId.match(/^segment-([^-]+)-/);
+          if (match) {
+            const topicId = match[1];
+            const topic = topics.topics?.find((t) => t.id === topicId);
+            if (topic && activeTopic?.id !== topic.id) {
+              setActiveTopic(topic);
+            }
+          }
+        }
+      },
+      {
+        threshold: [0, 0.25, 0.5, 0.75, 1],
+        rootMargin: "-20% 0px -20% 0px",
+      },
+    );
+
+    // Observe all segment elements
+    const segments = document.querySelectorAll('[id^="segment-"]');
+    segments.forEach((segment) => observer.observe(segment));
+
+    return () => observer.disconnect();
+  }, [topics.topics, activeTopic?.id, setActiveTopic]);
+
+  // Scroll handlers for bidirectional navigation
+  const handleTopicClick = (topicId: string) => {
+    // Scroll to first segment of this topic in transcript
+    const firstSegment = document.querySelector(`[id^="segment-${topicId}-"]`);
+    if (firstSegment) {
+      firstSegment.scrollIntoView({
+        behavior: "smooth",
+        block: "center",
+      });
+    }
+  };
+
+  const handleGutterClick = (topicId: string) => {
+    // Scroll to topic in list
+    const topicChip = document.getElementById(`topic-${topicId}`);
+    if (topicChip) {
+      topicChip.scrollIntoView({
+        behavior: "smooth",
+        block: "center",
+      });
+    }
+  };
+
+  const getSpeakerName = (speakerNumber: number) => {
+    if (!participants.response) return `Speaker ${speakerNumber}`;
+    return (
+      participants.response.find(
+        (participant) => participant.speaker == speakerNumber,
+      )?.name || `Speaker ${speakerNumber}`
+    );
+  };
+
   useEffect(() => {
     if (!waiting || !transcript.data) return;
 
@@ -121,7 +200,7 @@ export default function TranscriptDetails(details: TranscriptDetails) {
     <>
       <Grid
         templateColumns="1fr"
-        templateRows="auto minmax(0, 1fr)"
+        templateRows="auto auto"
         gap={4}
         mt={4}
         mb={4}
@@ -153,18 +232,18 @@ export default function TranscriptDetails(details: TranscriptDetails) {
         <Grid
           templateColumns={{ base: "minmax(0, 1fr)", md: "repeat(2, 1fr)" }}
           templateRows={{
-            base: "auto minmax(0, 1fr) minmax(0, 1fr)",
-            md: "auto minmax(0, 1fr)",
+            base: "auto auto auto",
+            md: "auto auto",
           }}
           gap={4}
           gridRowGap={2}
           padding={4}
-          paddingBottom={0}
           background="gray.bg"
           border={"2px solid"}
           borderColor={"gray.bg"}
           borderRadius={8}
         >
+          {/* Title */}
           <GridItem colSpan={{ base: 1, md: 2 }}>
             <Flex direction="column" gap={0}>
               <Flex alignItems="center" gap={2}>
@@ -187,28 +266,64 @@ export default function TranscriptDetails(details: TranscriptDetails) {
               )}
             </Flex>
           </GridItem>
-          <TopicList
-            topics={topics.topics || []}
-            useActiveTopic={useActiveTopic}
-            autoscroll={false}
-            transcriptId={transcriptId}
-            status={transcript.data?.status || null}
-            currentTranscriptText=""
-          />
-          {transcript.data && topics.topics ? (
-            <>
-              <FinalSummary
-                transcript={transcript.data}
-                topics={topics.topics}
-                onUpdate={() => {
-                  transcript.refetch().then(() => {});
+
+          {/* Left column: Topics List */}
+          <GridItem display="flex" flexDirection="column" gap={4} h="100%">
+            <TopicList
+              topics={topics.topics || []}
+              useActiveTopic={useActiveTopic}
+              autoscroll={false}
+              transcriptId={transcriptId}
+              status={transcript.data?.status || null}
+              currentTranscriptText=""
+              onTopicClick={handleTopicClick}
+            />
+
+            {/* Transcript with colored gutter (scrollable) */}
+            {topics.topics && topics.topics.length > 0 && (
+              <Box
+                overflowY="auto"
+                flex={1}
+                minH="0"
+                pr={2}
+                css={{
+                  "&::-webkit-scrollbar": {
+                    width: "8px",
+                  },
+                  "&::-webkit-scrollbar-track": {
+                    background: "transparent",
+                  },
+                  "&::-webkit-scrollbar-thumb": {
+                    background: "#CBD5E0",
+                    borderRadius: "4px",
+                  },
+                  "&::-webkit-scrollbar-thumb:hover": {
+                    background: "#A0AEC0",
+                  },
                 }}
-                finalSummaryRef={setFinalSummaryElement}
-              />
-            </>
+              >
+                <TranscriptWithGutter
+                  topics={topics.topics}
+                  getSpeakerName={getSpeakerName}
+                  onGutterClick={handleGutterClick}
+                />
+              </Box>
+            )}
+          </GridItem>
+
+          {/* Right column: Final Summary */}
+          {transcript.data && topics.topics ? (
+            <FinalSummary
+              transcript={transcript.data}
+              topics={topics.topics}
+              onUpdate={() => {
+                transcript.refetch().then(() => {});
+              }}
+              finalSummaryRef={setFinalSummaryElement}
+            />
           ) : (
-            <Flex justify={"center"} alignItems={"center"} h={"100%"}>
-              <div className="flex flex-col h-full justify-center content-center">
+            <Flex justify="center" alignItems="center" h="100%">
+              <Flex direction="column" h="full" justify="center" align="center">
                 {transcript?.data?.status == "processing" ? (
                   <Text>Loading Transcript</Text>
                 ) : (
@@ -217,7 +332,7 @@ export default function TranscriptDetails(details: TranscriptDetails) {
                     back later
                   </Text>
                 )}
-              </div>
+              </Flex>
             </Flex>
           )}
         </Grid>

www/app/lib/topicColors.ts

@@ -0,0 +1,18 @@
+// Predefined color palette for topics
+// Colors chosen for good contrast and visual distinction
+export const TOPIC_COLORS = [
+  "#3B82F6", // blue
+  "#10B981", // green
+  "#F59E0B", // amber
+  "#EF4444", // red
+  "#8B5CF6", // violet
+  "#EC4899", // pink
+  "#14B8A6", // teal
+  "#F97316", // orange
+  "#6366F1", // indigo
+  "#84CC16", // lime
+] as const;
+
+export function getTopicColor(topicIndex: number): string {
+  return TOPIC_COLORS[topicIndex % TOPIC_COLORS.length];
+}