fix(pagination): add insert_id UUID tiebreak to cursor keyset

Same-millisecond rows were silently skipped between pages because the
log cursor had no tiebreak and the events cursor tied by instance_id
(which also collides when one instance emits multiple events within a
millisecond). Add an insert_id UUID (DEFAULT generateUUIDv4()) column
to both logs and agent_events, order by (timestamp, insert_id)
consistently, and encode the cursor as 'timestamp|insert_id'. Existing
data is materialized via ALTER TABLE MATERIALIZE COLUMN (one-time
background mutation).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/rules/app-classes.md

@@ -43,11 +43,11 @@ ClickHouse is shared across tenants. Every ClickHouse query must filter by `tena
 - `ApplicationConfigController` — `/api/v1/environments/{envSlug}`. GET `/config` (list), GET/PUT `/apps/{appSlug}/config`, GET `/apps/{appSlug}/processor-routes`, POST `/apps/{appSlug}/config/test-expression`. PUT also pushes `CONFIG_UPDATE` to LIVE agents in this env.
 - `AppSettingsController` — `/api/v1/environments/{envSlug}`. GET `/app-settings` (list), GET/PUT/DELETE `/apps/{appSlug}/settings`. ADMIN/OPERATOR only.
 - `SearchController` — `/api/v1/environments/{envSlug}`. GET `/executions`, POST `/executions/search`, GET `/stats`, `/stats/timeseries`, `/stats/timeseries/by-app`, `/stats/timeseries/by-route`, `/stats/punchcard`, `/attributes/keys`, `/errors/top`.
-- `LogQueryController` — GET `/api/v1/environments/{envSlug}/logs` (filters: source, application, agentId, exchangeId, level, logger, q, time range).
+- `LogQueryController` — GET `/api/v1/environments/{envSlug}/logs` (filters: source (multi, comma-split, OR-joined), level (multi, comma-split, OR-joined), application, agentId, exchangeId, logger, q, time range). Cursor-paginated.
 - `RouteCatalogController` — GET `/api/v1/environments/{envSlug}/routes` (merged route catalog from registry + ClickHouse; env filter unconditional).
 - `RouteMetricsController` — GET `/api/v1/environments/{envSlug}/routes/metrics`, GET `/api/v1/environments/{envSlug}/routes/metrics/processors`.
 - `AgentListController` — GET `/api/v1/environments/{envSlug}/agents` (registered agents with runtime metrics, filtered to env).
-- `AgentEventsController` — GET `/api/v1/environments/{envSlug}/agents/events` (lifecycle events).
+- `AgentEventsController` — GET `/api/v1/environments/{envSlug}/agents/events` (lifecycle events; cursor-paginated, returns `{ data, nextCursor, hasMore }`; order `(timestamp DESC, instance_id ASC)`; cursor is base64url of `"{timestampIso}|{instanceId}"`).
 - `AgentMetricsController` — GET `/api/v1/environments/{envSlug}/agents/{agentId}/metrics` (JVM/Camel metrics). Rejects cross-env agents (404) as defence-in-depth.
 - `DiagramRenderController` — GET `/api/v1/environments/{envSlug}/apps/{appSlug}/routes/{routeId}/diagram` (env-scoped lookup). Also GET `/api/v1/diagrams/{contentHash}/render` (flat — content hashes are globally unique).
 

.claude/rules/ui.md

@@ -29,7 +29,10 @@ The UI has 4 main tabs: **Exchanges**, **Dashboard**, **Runtime**, **Deployments
 - `ui/src/components/ProcessDiagram/` — ELK-rendered route diagram
 - `ui/src/hooks/useScope.ts` — TabKey type, scope inference
 - `ui/src/components/StartupLogPanel.tsx` — deployment startup log viewer (container logs from ClickHouse, polls 3s while STARTING)
-- `ui/src/api/queries/logs.ts` — `useStartupLogs` hook for container startup log polling, `useLogs`/`useApplicationLogs` for general log search
+- `ui/src/api/queries/logs.ts` — `useStartupLogs` hook for container startup log polling, `useLogs`/`useApplicationLogs` for bounded log search (single page), `useInfiniteApplicationLogs` for streaming log views (cursor-paginated, server-side source/level filters)
+- `ui/src/api/queries/agents.ts` — `useAgents` for agent list, `useInfiniteAgentEvents` for cursor-paginated timeline stream
+- `ui/src/hooks/useInfiniteStream.ts` — tanstack `useInfiniteQuery` wrapper with top-gated auto-refetch, flattened `items[]`, and `refresh()` invalidator
+- `ui/src/components/InfiniteScrollArea.tsx` — scrollable container with IntersectionObserver top/bottom sentinels. Streaming log/event views use this + `useInfiniteStream`. Bounded views (LogTab, StartupLogPanel) keep `useLogs`/`useStartupLogs`
 
 ## UI Styling
 

cameleer-server-app/src/main/java/com/cameleer/server/app/controller/AgentEventsController.java

@@ -1,7 +1,9 @@
 package com.cameleer.server.app.controller;
 
+import com.cameleer.server.app.dto.AgentEventPageResponse;
 import com.cameleer.server.app.dto.AgentEventResponse;
 import com.cameleer.server.app.web.EnvPath;
+import com.cameleer.server.core.agent.AgentEventPage;
 import com.cameleer.server.core.agent.AgentEventService;
 import com.cameleer.server.core.runtime.Environment;
 import io.swagger.v3.oas.annotations.Operation;
@@ -14,7 +16,6 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.time.Instant;
-import java.util.List;
 
 @RestController
 @RequestMapping("/api/v1/environments/{envSlug}/agents/events")
@@ -29,24 +30,25 @@ public class AgentEventsController {
 
     @GetMapping
     @Operation(summary = "Query agent events in this environment",
-            description = "Returns agent lifecycle events, optionally filtered by app and/or agent ID")
-    @ApiResponse(responseCode = "200", description = "Events returned")
-    public ResponseEntity<List<AgentEventResponse>> getEvents(
+            description = "Cursor-paginated. Returns newest first. Pass nextCursor back as ?cursor= for the next page.")
+    @ApiResponse(responseCode = "200", description = "Event page returned")
+    public ResponseEntity<AgentEventPageResponse> getEvents(
             @EnvPath Environment env,
             @RequestParam(required = false) String appId,
             @RequestParam(required = false) String agentId,
             @RequestParam(required = false) String from,
             @RequestParam(required = false) String to,
+            @RequestParam(required = false) String cursor,
             @RequestParam(defaultValue = "50") int limit) {
 
         Instant fromInstant = from != null ? Instant.parse(from) : null;
         Instant toInstant = to != null ? Instant.parse(to) : null;
 
-        var events = agentEventService.queryEvents(appId, agentId, env.slug(), fromInstant, toInstant, limit)
-                .stream()
-                .map(AgentEventResponse::from)
-                .toList();
+        AgentEventPage page = agentEventService.queryEventPage(
+                appId, agentId, env.slug(), fromInstant, toInstant, cursor, limit);
 
-        return ResponseEntity.ok(events);
+        var data = page.data().stream().map(AgentEventResponse::from).toList();
+
+        return ResponseEntity.ok(new AgentEventPageResponse(data, page.nextCursor(), page.hasMore()));
     }
 }

cameleer-server-app/src/main/java/com/cameleer/server/app/controller/ApiExceptionHandler.java

@@ -6,6 +6,8 @@ import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 import org.springframework.web.server.ResponseStatusException;
 
+import java.time.format.DateTimeParseException;
+
 /**
  * Global exception handler that ensures error responses use the typed {@link ErrorResponse} schema.
  */
@@ -18,4 +20,11 @@ public class ApiExceptionHandler {
         return ResponseEntity.status(ex.getStatusCode())
                 .body(new ErrorResponse(reason != null ? reason : "Unknown error"));
     }
+
+    @ExceptionHandler({DateTimeParseException.class, IllegalArgumentException.class})
+    public ResponseEntity<ErrorResponse> handleBadRequest(Exception ex) {
+        String msg = ex.getMessage();
+        return ResponseEntity.badRequest()
+                .body(new ErrorResponse(msg != null ? msg : "Bad request"));
+    }
 }

cameleer-server-app/src/main/java/com/cameleer/server/app/controller/LogQueryController.java

@@ -61,12 +61,20 @@ public class LogQueryController {
                     .toList();
         }
 
+        List<String> sources = List.of();
+        if (source != null && !source.isEmpty()) {
+            sources = Arrays.stream(source.split(","))
+                    .map(String::trim)
+                    .filter(s -> !s.isEmpty())
+                    .toList();
+        }
+
         Instant fromInstant = from != null ? Instant.parse(from) : null;
         Instant toInstant = to != null ? Instant.parse(to) : null;
 
         LogSearchRequest request = new LogSearchRequest(
                 searchText, levels, application, instanceId, exchangeId,
-                logger, env.slug(), source, fromInstant, toInstant, cursor, limit, sort);
+                logger, env.slug(), sources, fromInstant, toInstant, cursor, limit, sort);
 
         LogSearchResponse result = logIndex.search(request);
 

cameleer-server-app/src/main/java/com/cameleer/server/app/dto/AgentEventPageResponse.java

@@ -0,0 +1,12 @@
+package com.cameleer.server.app.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.util.List;
+
+@Schema(description = "Cursor-paginated agent event list")
+public record AgentEventPageResponse(
+        List<AgentEventResponse> data,
+        String nextCursor,
+        boolean hasMore
+) {}

cameleer-server-app/src/main/java/com/cameleer/server/app/search/ClickHouseLogStore.java

@@ -10,13 +10,11 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
 
-import java.sql.Timestamp;
+import java.nio.charset.StandardCharsets;
 import java.time.Instant;
-import java.time.ZoneOffset;
-import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
+import java.util.Base64;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -29,7 +27,6 @@ import java.util.Map;
 public class ClickHouseLogStore implements LogIndex {
 
     private static final Logger log = LoggerFactory.getLogger(ClickHouseLogStore.class);
-    private static final DateTimeFormatter ISO_FMT = DateTimeFormatter.ISO_INSTANT;
 
     private final String tenantId;
     private final JdbcTemplate jdbc;
@@ -47,12 +44,12 @@ public class ClickHouseLogStore implements LogIndex {
 
         String sql = "INSERT INTO logs (tenant_id, timestamp, application, instance_id, level, " +
                 "logger_name, message, thread_name, stack_trace, exchange_id, mdc, source) " +
-                "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
+                "VALUES (?, parseDateTime64BestEffort(?, 3), ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
 
         jdbc.batchUpdate(sql, entries, entries.size(), (ps, entry) -> {
             Instant ts = entry.getTimestamp() != null ? entry.getTimestamp() : Instant.now();
             ps.setString(1, tenantId);
-            ps.setTimestamp(2, Timestamp.from(ts));
+            ps.setString(2, ts.toString());
             ps.setString(3, applicationId);
             ps.setString(4, instanceId);
             ps.setString(5, entry.getLevel() != null ? entry.getLevel() : "");
@@ -76,14 +73,14 @@ public class ClickHouseLogStore implements LogIndex {
 
         String sql = "INSERT INTO logs (tenant_id, environment, timestamp, application, instance_id, level, " +
                 "logger_name, message, thread_name, stack_trace, exchange_id, mdc, source) " +
-                "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
+                "VALUES (?, ?, parseDateTime64BestEffort(?, 3), ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
 
         jdbc.batchUpdate(sql, entries, entries.size(), (ps, ble) -> {
             LogEntry entry = ble.entry();
             Instant ts = entry.getTimestamp() != null ? entry.getTimestamp() : Instant.now();
             ps.setString(1, ble.tenantId() != null ? ble.tenantId() : tenantId);
             ps.setString(2, ble.environment() != null ? ble.environment() : "default");
-            ps.setTimestamp(3, Timestamp.from(ts));
+            ps.setString(3, ts.toString());
             ps.setString(4, ble.applicationId());
             ps.setString(5, ble.instanceId());
             ps.setString(6, entry.getLevel() != null ? entry.getLevel() : "");
@@ -146,19 +143,22 @@ public class ClickHouseLogStore implements LogIndex {
             baseParams.add("%" + escapeLike(request.logger()) + "%");
         }
 
-        if (request.source() != null && !request.source().isEmpty()) {
-            baseConditions.add("source = ?");
-            baseParams.add(request.source());
+        if (request.sources() != null && !request.sources().isEmpty()) {
+            String placeholders = String.join(", ", Collections.nCopies(request.sources().size(), "?"));
+            baseConditions.add("source IN (" + placeholders + ")");
+            for (String s : request.sources()) {
+                baseParams.add(s);
+            }
         }
 
         if (request.from() != null) {
-            baseConditions.add("timestamp >= ?");
-            baseParams.add(Timestamp.from(request.from()));
+            baseConditions.add("timestamp >= parseDateTime64BestEffort(?, 3)");
+            baseParams.add(request.from().toString());
         }
 
         if (request.to() != null) {
-            baseConditions.add("timestamp <= ?");
-            baseParams.add(Timestamp.from(request.to()));
+            baseConditions.add("timestamp <= parseDateTime64BestEffort(?, 3)");
+            baseParams.add(request.to().toString());
         }
 
         // Level counts query: uses base conditions WITHOUT level filter and cursor
@@ -178,30 +178,44 @@ public class ClickHouseLogStore implements LogIndex {
         }
 
         if (request.cursor() != null && !request.cursor().isEmpty()) {
-            Instant cursorTs = Instant.parse(request.cursor());
-            if ("asc".equalsIgnoreCase(request.sort())) {
-                dataConditions.add("timestamp > ?");
-            } else {
-                dataConditions.add("timestamp < ?");
+            String decoded = new String(Base64.getUrlDecoder().decode(request.cursor()),
+                    StandardCharsets.UTF_8);
+            int bar = decoded.indexOf('|');
+            if (bar <= 0 || bar == decoded.length() - 1) {
+                throw new IllegalArgumentException("Malformed cursor");
             }
-            dataParams.add(Timestamp.from(cursorTs));
+            Instant cursorTs;
+            try {
+                cursorTs = Instant.parse(decoded.substring(0, bar));
+            } catch (java.time.format.DateTimeParseException e) {
+                throw new IllegalArgumentException("Malformed cursor", e);
+            }
+            String cursorId = decoded.substring(bar + 1);
+            String cmp = "asc".equalsIgnoreCase(request.sort()) ? ">" : "<";
+            dataConditions.add(
+                    "(timestamp " + cmp + " parseDateTime64BestEffort(?, 3)" +
+                    " OR (timestamp = parseDateTime64BestEffort(?, 3) AND insert_id " + cmp + " toUUID(?)))");
+            dataParams.add(cursorTs.toString());
+            dataParams.add(cursorTs.toString());
+            dataParams.add(cursorId);
         }
 
         String dataWhere = String.join(" AND ", dataConditions);
         String orderDir = "asc".equalsIgnoreCase(request.sort()) ? "ASC" : "DESC";
         int fetchLimit = request.limit() + 1; // fetch N+1 to detect hasMore
 
-        String dataSql = "SELECT timestamp, level, logger_name, message, thread_name, stack_trace, " +
-                "exchange_id, instance_id, application, mdc, source " +
+        String dataSql = "SELECT formatDateTime(timestamp, '%Y-%m-%dT%H:%i:%S', 'UTC') AS ts_utc," +
+                " toUnixTimestamp64Milli(timestamp) AS ts_millis," +
+                " level, logger_name, message, thread_name, stack_trace, " +
+                "exchange_id, instance_id, application, mdc, source, toString(insert_id) AS insert_id_str " +
                 "FROM logs WHERE " + dataWhere +
-                " ORDER BY timestamp " + orderDir + " LIMIT ?";
+                " ORDER BY timestamp " + orderDir + ", insert_id " + orderDir + " LIMIT ?";
         dataParams.add(fetchLimit);
 
+        List<String> insertIds = new ArrayList<>();
         List<LogEntryResult> results = jdbc.query(dataSql, dataParams.toArray(), (rs, rowNum) -> {
-            Timestamp ts = rs.getTimestamp("timestamp");
-            String timestampStr = ts != null
-                    ? ts.toInstant().atOffset(ZoneOffset.UTC).format(ISO_FMT)
-                    : null;
+            long tsMillis = rs.getLong("ts_millis");
+            String timestampStr = Instant.ofEpochMilli(tsMillis).toString();
 
             @SuppressWarnings("unchecked")
             Map<String, String> mdc = (Map<String, String>) rs.getObject("mdc");
@@ -209,6 +223,8 @@ public class ClickHouseLogStore implements LogIndex {
 
             String source = rs.getString("source");
 
+            insertIds.add(rs.getString("insert_id_str"));
+
             return new LogEntryResult(
                     timestampStr,
                     rs.getString("level"),
@@ -231,7 +247,10 @@ public class ClickHouseLogStore implements LogIndex {
 
         String nextCursor = null;
         if (hasMore && !results.isEmpty()) {
-            nextCursor = results.get(results.size() - 1).timestamp();
+            int lastIdx = results.size() - 1;
+            String raw = results.get(lastIdx).timestamp() + "|" + insertIds.get(lastIdx);
+            nextCursor = Base64.getUrlEncoder().withoutPadding()
+                    .encodeToString(raw.getBytes(StandardCharsets.UTF_8));
         }
 
         return new LogSearchResponse(results, nextCursor, hasMore, levelCounts);

cameleer-server-app/src/main/java/com/cameleer/server/app/storage/ClickHouseAgentEventRepository.java

@@ -1,12 +1,15 @@
 package com.cameleer.server.app.storage;
 
+import com.cameleer.server.core.agent.AgentEventPage;
 import com.cameleer.server.core.agent.AgentEventRecord;
 import com.cameleer.server.core.agent.AgentEventRepository;
 import org.springframework.jdbc.core.JdbcTemplate;
 
+import java.nio.charset.StandardCharsets;
 import java.sql.Timestamp;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.Base64;
 import java.util.List;
 
 /**
@@ -21,7 +24,7 @@ public class ClickHouseAgentEventRepository implements AgentEventRepository {
             "INSERT INTO agent_events (tenant_id, instance_id, application_id, environment, event_type, detail) VALUES (?, ?, ?, ?, ?, ?)";
 
     private static final String SELECT_BASE =
-            "SELECT 0 AS id, instance_id, application_id, event_type, detail, timestamp FROM agent_events WHERE tenant_id = ?";
+            "SELECT 0 AS id, instance_id, application_id, event_type, detail, timestamp, toString(insert_id) AS insert_id_str FROM agent_events WHERE tenant_id = ?";
 
     private final String tenantId;
     private final JdbcTemplate jdbc;
@@ -38,41 +41,69 @@ public class ClickHouseAgentEventRepository implements AgentEventRepository {
     }
 
     @Override
-    public List<AgentEventRecord> query(String applicationId, String instanceId, String environment, Instant from, Instant to, int limit) {
+    public AgentEventPage queryPage(String applicationId, String instanceId, String environment,
+                                     Instant from, Instant to, String cursor, int limit) {
         var sql = new StringBuilder(SELECT_BASE);
         var params = new ArrayList<Object>();
         params.add(tenantId);
 
-        if (applicationId != null) {
-            sql.append(" AND application_id = ?");
-            params.add(applicationId);
-        }
-        if (instanceId != null) {
-            sql.append(" AND instance_id = ?");
-            params.add(instanceId);
-        }
-        if (environment != null) {
-            sql.append(" AND environment = ?");
-            params.add(environment);
-        }
-        if (from != null) {
-            sql.append(" AND timestamp >= ?");
-            params.add(Timestamp.from(from));
-        }
-        if (to != null) {
-            sql.append(" AND timestamp < ?");
-            params.add(Timestamp.from(to));
-        }
-        sql.append(" ORDER BY timestamp DESC LIMIT ?");
-        params.add(limit);
+        if (applicationId != null) { sql.append(" AND application_id = ?"); params.add(applicationId); }
+        if (instanceId != null) { sql.append(" AND instance_id = ?"); params.add(instanceId); }
+        if (environment != null) { sql.append(" AND environment = ?"); params.add(environment); }
+        if (from != null) { sql.append(" AND timestamp >= ?"); params.add(Timestamp.from(from)); }
+        if (to != null) { sql.append(" AND timestamp < ?"); params.add(Timestamp.from(to)); }
 
-        return jdbc.query(sql.toString(), (rs, rowNum) -> new AgentEventRecord(
-                rs.getLong("id"),
-                rs.getString("instance_id"),
-                rs.getString("application_id"),
-                rs.getString("event_type"),
-                rs.getString("detail"),
-                rs.getTimestamp("timestamp").toInstant()
-        ), params.toArray());
+        if (cursor != null && !cursor.isEmpty()) {
+            String decoded = new String(Base64.getUrlDecoder().decode(cursor), StandardCharsets.UTF_8);
+            int bar = decoded.indexOf('|');
+            if (bar <= 0 || bar == decoded.length() - 1) {
+                throw new IllegalArgumentException("Malformed cursor");
+            }
+            Instant cursorTs;
+            try {
+                cursorTs = Instant.parse(decoded.substring(0, bar));
+            } catch (java.time.format.DateTimeParseException e) {
+                throw new IllegalArgumentException("Malformed cursor", e);
+            }
+            String cursorInsertId = decoded.substring(bar + 1);
+            sql.append(" AND (timestamp < ? OR (timestamp = ? AND insert_id < toUUID(?)))");
+            params.add(Timestamp.from(cursorTs));
+            params.add(Timestamp.from(cursorTs));
+            params.add(cursorInsertId);
+        }
+
+        sql.append(" ORDER BY timestamp DESC, insert_id DESC LIMIT ?");
+        int fetchLimit = limit + 1;
+        params.add(fetchLimit);
+
+        List<String> insertIds = new ArrayList<>();
+        List<AgentEventRecord> results = new ArrayList<>(jdbc.query(sql.toString(),
+                (rs, rowNum) -> {
+                    insertIds.add(rs.getString("insert_id_str"));
+                    return new AgentEventRecord(
+                            rs.getLong("id"),
+                            rs.getString("instance_id"),
+                            rs.getString("application_id"),
+                            rs.getString("event_type"),
+                            rs.getString("detail"),
+                            rs.getTimestamp("timestamp").toInstant()
+                    );
+                }, params.toArray()));
+
+        boolean hasMore = results.size() > limit;
+        if (hasMore) {
+            results = new ArrayList<>(results.subList(0, limit));
+        }
+
+        String nextCursor = null;
+        if (hasMore && !results.isEmpty()) {
+            int lastIdx = results.size() - 1;
+            AgentEventRecord last = results.get(lastIdx);
+            String raw = last.timestamp().toString() + "|" + insertIds.get(lastIdx);
+            nextCursor = Base64.getUrlEncoder().withoutPadding()
+                    .encodeToString(raw.getBytes(StandardCharsets.UTF_8));
+        }
+
+        return new AgentEventPage(results, nextCursor, hasMore);
     }
 }

cameleer-server-app/src/main/resources/clickhouse/init.sql

@@ -327,7 +327,8 @@ CREATE TABLE IF NOT EXISTS agent_events (
     instance_id    LowCardinality(String),
     application_id LowCardinality(String),
     event_type     LowCardinality(String),
-    detail         String DEFAULT ''
+    detail         String DEFAULT '',
+    insert_id      UUID DEFAULT generateUUIDv4()
 )
 ENGINE = MergeTree()
 PARTITION BY (tenant_id, toYYYYMM(timestamp))
@@ -349,6 +350,7 @@ CREATE TABLE IF NOT EXISTS logs (
     stack_trace  String DEFAULT '',
     exchange_id  String DEFAULT '',
     mdc          Map(String, String) DEFAULT map(),
+    insert_id    UUID DEFAULT generateUUIDv4(),
 
     INDEX idx_msg   message TYPE ngrambf_v1(3, 256, 2, 0) GRANULARITY 4,
     INDEX idx_stack stack_trace TYPE ngrambf_v1(3, 256, 2, 0) GRANULARITY 4,
@@ -398,3 +400,12 @@ CREATE TABLE IF NOT EXISTS route_catalog (
 )
 ENGINE = ReplacingMergeTree(last_seen)
 ORDER BY (tenant_id, environment, application_id, route_id);
+
+-- insert_id tiebreak for keyset pagination (fixes same-millisecond cursor collision).
+-- IF NOT EXISTS on ADD COLUMN is idempotent. MATERIALIZE COLUMN is a background mutation,
+-- effectively a no-op once all parts are already materialized.
+ALTER TABLE logs ADD COLUMN IF NOT EXISTS insert_id UUID DEFAULT generateUUIDv4();
+ALTER TABLE logs MATERIALIZE COLUMN insert_id;
+
+ALTER TABLE agent_events ADD COLUMN IF NOT EXISTS insert_id UUID DEFAULT generateUUIDv4();
+ALTER TABLE agent_events MATERIALIZE COLUMN insert_id;

cameleer-server-app/src/test/java/com/cameleer/server/app/search/ClickHouseLogStoreIT.java

@@ -323,4 +323,78 @@ class ClickHouseLogStoreIT {
                 String.class);
         assertThat(customVal).isEqualTo("custom-value");
     }
+
+    @Test
+    void search_bySources_singleValue_filtersCorrectly() {
+        Instant now = Instant.parse("2026-03-31T12:00:00Z");
+        // "source" column is populated by indexBatch via LogEntry.getSource(); default is "app" when null.
+        // Force one row to "container" via a direct insert to avoid coupling to LogEntry constructor.
+        store.indexBatch("agent-1", "my-app", List.of(
+                entry(now, "INFO", "logger", "app msg", "t1", null, null)
+        ));
+        jdbc.update("INSERT INTO logs (tenant_id, environment, timestamp, application, instance_id, level, " +
+                "logger_name, message, thread_name, stack_trace, exchange_id, mdc, source) VALUES " +
+                "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+                "default", "default", java.sql.Timestamp.from(now.plusSeconds(1)), "my-app", "agent-1",
+                "INFO", "logger", "container msg", "t1", "", "", java.util.Map.of(), "container");
+
+        LogSearchResponse result = store.search(new LogSearchRequest(
+                null, null, "my-app", null, null, null, null,
+                List.of("container"), null, null, null, 100, "desc"));
+
+        assertThat(result.data()).hasSize(1);
+        assertThat(result.data().get(0).message()).isEqualTo("container msg");
+    }
+
+    @Test
+    void search_bySources_multiValue_joinsAsOr() {
+        Instant now = Instant.parse("2026-03-31T12:00:00Z");
+        store.indexBatch("agent-1", "my-app", List.of(
+                entry(now, "INFO", "logger", "app msg", "t1", null, null)
+        ));
+        jdbc.update("INSERT INTO logs (tenant_id, environment, timestamp, application, instance_id, level, " +
+                "logger_name, message, thread_name, stack_trace, exchange_id, mdc, source) VALUES " +
+                "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+                "default", "default", java.sql.Timestamp.from(now.plusSeconds(1)), "my-app", "agent-1",
+                "INFO", "logger", "container msg", "t1", "", "", java.util.Map.of(), "container");
+        jdbc.update("INSERT INTO logs (tenant_id, environment, timestamp, application, instance_id, level, " +
+                "logger_name, message, thread_name, stack_trace, exchange_id, mdc, source) VALUES " +
+                "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+                "default", "default", java.sql.Timestamp.from(now.plusSeconds(2)), "my-app", "agent-1",
+                "INFO", "logger", "agent msg", "t1", "", "", java.util.Map.of(), "agent");
+
+        LogSearchResponse result = store.search(new LogSearchRequest(
+                null, null, "my-app", null, null, null, null,
+                List.of("app", "container"), null, null, null, 100, "desc"));
+
+        assertThat(result.data()).hasSize(2);
+        assertThat(result.data()).extracting(LogEntryResult::message)
+                .containsExactlyInAnyOrder("app msg", "container msg");
+    }
+
+    @Test
+    void search_cursorPagination_sameMillisecond_doesNotSkip() {
+        Instant ts = Instant.parse("2026-04-17T10:00:00Z");
+        // Insert 5 rows at the exact same timestamp
+        java.util.List<LogEntry> batch = new java.util.ArrayList<>();
+        for (int i = 0; i < 5; i++) {
+            batch.add(entry(ts, "INFO", "logger", "msg-" + i, "t1", null, null));
+        }
+        store.indexBatch("agent-1", "my-app", batch);
+
+        // Page through with limit 2; across 3 pages we must see all 5 distinct messages, no duplicates
+        java.util.Set<String> seen = new java.util.HashSet<>();
+        String cursor = null;
+        for (int page = 0; page < 10; page++) {
+            LogSearchResponse resp = store.search(new LogSearchRequest(
+                    null, null, "my-app", null, null, null, null, null,
+                    null, null, cursor, 2, "desc"));
+            for (LogEntryResult r : resp.data()) {
+                assertThat(seen.add(r.message())).as("duplicate row returned: " + r.message()).isTrue();
+            }
+            cursor = resp.nextCursor();
+            if (!resp.hasMore()) break;
+        }
+        assertThat(seen).containsExactlyInAnyOrder("msg-0", "msg-1", "msg-2", "msg-3", "msg-4");
+    }
 }

cameleer-server-app/src/test/java/com/cameleer/server/app/storage/ClickHouseAgentEventRepositoryIT.java

@@ -1,6 +1,5 @@
 package com.cameleer.server.app.storage;
 
-import com.cameleer.server.core.agent.AgentEventRecord;
 import com.zaxxer.hikari.HikariDataSource;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -10,10 +9,8 @@ import org.testcontainers.clickhouse.ClickHouseContainer;
 import org.testcontainers.junit.jupiter.Container;
 import org.testcontainers.junit.jupiter.Testcontainers;
 
-import java.nio.charset.StandardCharsets;
 import java.sql.Timestamp;
 import java.time.Instant;
-import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -66,91 +63,97 @@ class ClickHouseAgentEventRepositoryIT {
     }
 
     @Test
-    void query_byAppId_filtersCorrectly() {
-        repo.insert("agent-1", "app-x", "default", "CONNECTED", "");
-        repo.insert("agent-2", "app-y", "default", "DISCONNECTED", "");
-
-        List<AgentEventRecord> results = repo.query("app-x", null, null, null, null, 100);
-
-        assertThat(results).hasSize(1);
-        assertThat(results.get(0).applicationId()).isEqualTo("app-x");
-        assertThat(results.get(0).instanceId()).isEqualTo("agent-1");
+    void queryPage_emptyTable_returnsEmptyPage() {
+        com.cameleer.server.core.agent.AgentEventPage page =
+                repo.queryPage(null, null, null, null, null, null, 10);
+        assertThat(page.data()).isEmpty();
+        assertThat(page.hasMore()).isFalse();
+        assertThat(page.nextCursor()).isNull();
     }
 
     @Test
-    void query_byAgentId_filtersCorrectly() {
-        repo.insert("agent-alpha", "app-shared", "default", "CONNECTED", "");
-        repo.insert("agent-beta", "app-shared", "default", "CONNECTED", "");
-
-        List<AgentEventRecord> results = repo.query(null, "agent-alpha", null, null, null, 100);
-
-        assertThat(results).hasSize(1);
-        assertThat(results.get(0).instanceId()).isEqualTo("agent-alpha");
+    void queryPage_boundary_noHasMoreWhenLimitEqualsRowCount() {
+        Instant base = Instant.parse("2026-04-01T10:00:00Z");
+        for (int i = 0; i < 3; i++) {
+            insertAt("agent-1", "app-a", "TICK", "t" + i, base.plusSeconds(i));
+        }
+        com.cameleer.server.core.agent.AgentEventPage page =
+                repo.queryPage(null, null, null, null, null, null, 3);
+        assertThat(page.data()).hasSize(3);
+        assertThat(page.hasMore()).isFalse();
+        assertThat(page.nextCursor()).isNull();
     }
 
     @Test
-    void query_byTimeRange_filtersCorrectly() {
-        Instant t1 = Instant.parse("2026-01-01T10:00:00Z");
-        Instant t2 = Instant.parse("2026-01-01T11:00:00Z");
-        Instant t3 = Instant.parse("2026-01-01T12:00:00Z");
-
-        insertAt("agent-1", "app-a", "CONNECTED", "early", t1);
-        insertAt("agent-1", "app-a", "HEARTBEAT", "mid", t2);
-        insertAt("agent-1", "app-a", "DISCONNECTED", "late", t3);
-
-        // Query [t2, t3) — should return only the middle event
-        List<AgentEventRecord> results = repo.query(null, null, null, t2, t3, 100);
-
-        assertThat(results).hasSize(1);
-        assertThat(results.get(0).eventType()).isEqualTo("HEARTBEAT");
-    }
-
-    @Test
-    void query_respectsLimit() {
-        Instant base = Instant.parse("2026-02-01T00:00:00Z");
-        for (int i = 0; i < 10; i++) {
-            insertAt("agent-1", "app-a", "HEARTBEAT", "beat-" + i, base.plusSeconds(i));
+    void queryPage_paginatesAcrossThreePages() {
+        Instant base = Instant.parse("2026-04-01T10:00:00Z");
+        for (int i = 0; i < 5; i++) {
+            insertAt("agent-1", "app-a", "TICK", "t" + i, base.plusSeconds(i));
         }
 
-        List<AgentEventRecord> results = repo.query(null, null, null, null, null, 3);
+        com.cameleer.server.core.agent.AgentEventPage p1 =
+                repo.queryPage(null, null, null, null, null, null, 2);
+        assertThat(p1.data()).hasSize(2);
+        assertThat(p1.hasMore()).isTrue();
+        assertThat(p1.nextCursor()).isNotBlank();
+        assertThat(p1.data().get(0).detail()).isEqualTo("t4");
+        assertThat(p1.data().get(1).detail()).isEqualTo("t3");
 
-        assertThat(results).hasSize(3);
+        com.cameleer.server.core.agent.AgentEventPage p2 =
+                repo.queryPage(null, null, null, null, null, p1.nextCursor(), 2);
+        assertThat(p2.data()).hasSize(2);
+        assertThat(p2.hasMore()).isTrue();
+        assertThat(p2.data().get(0).detail()).isEqualTo("t2");
+        assertThat(p2.data().get(1).detail()).isEqualTo("t1");
+
+        com.cameleer.server.core.agent.AgentEventPage p3 =
+                repo.queryPage(null, null, null, null, null, p2.nextCursor(), 2);
+        assertThat(p3.data()).hasSize(1);
+        assertThat(p3.hasMore()).isFalse();
+        assertThat(p3.nextCursor()).isNull();
+        assertThat(p3.data().get(0).detail()).isEqualTo("t0");
     }
 
     @Test
-    void query_returnsZeroId() {
-        repo.insert("agent-1", "app-a", "default", "CONNECTED", "");
+    void queryPage_tiebreak_sameMillisecond_returnsAllRowsNoDuplicates() {
+        Instant ts = Instant.parse("2026-04-01T10:00:00Z");
+        insertAt("agent-a", "app-a", "TICK", "a", ts);
+        insertAt("agent-b", "app-a", "TICK", "b", ts);
+        insertAt("agent-c", "app-a", "TICK", "c", ts);
 
-        List<AgentEventRecord> results = repo.query(null, null, null, null, null, 10);
-
-        assertThat(results).hasSize(1);
-        assertThat(results.get(0).id()).isEqualTo(0L);
+        java.util.Set<String> seen = new java.util.HashSet<>();
+        String cursor = null;
+        for (int page = 0; page < 10; page++) {
+            com.cameleer.server.core.agent.AgentEventPage p =
+                    repo.queryPage(null, null, null, null, null, cursor, 1);
+            for (com.cameleer.server.core.agent.AgentEventRecord r : p.data()) {
+                assertThat(seen.add(r.instanceId())).as("duplicate row returned: " + r.instanceId()).isTrue();
+            }
+            cursor = p.nextCursor();
+            if (!p.hasMore()) break;
+        }
+        assertThat(seen).containsExactlyInAnyOrder("agent-a", "agent-b", "agent-c");
     }
 
     @Test
-    void query_noFilters_returnsAllEvents() {
-        repo.insert("agent-1", "app-a", "default", "CONNECTED", "");
-        repo.insert("agent-2", "app-b", "default", "DISCONNECTED", "");
+    void queryPage_malformedCursor_invalidTimestamp_throws() {
+        String raw = "not-a-timestamp|agent-1";
+        String cursor = java.util.Base64.getUrlEncoder().withoutPadding()
+                .encodeToString(raw.getBytes(java.nio.charset.StandardCharsets.UTF_8));
 
-        List<AgentEventRecord> results = repo.query(null, null, null, null, null, 100);
-
-        assertThat(results).hasSize(2);
+        org.junit.jupiter.api.Assertions.assertThrows(
+                IllegalArgumentException.class,
+                () -> repo.queryPage(null, null, null, null, null, cursor, 10));
     }
 
     @Test
-    void query_resultsOrderedByTimestampDesc() {
-        Instant t1 = Instant.parse("2026-03-01T08:00:00Z");
-        Instant t2 = Instant.parse("2026-03-01T09:00:00Z");
-        Instant t3 = Instant.parse("2026-03-01T10:00:00Z");
+    void queryPage_malformedCursor_emptyInsertId_throws() {
+        String raw = "2026-04-01T10:00:00Z|";
+        String cursor = java.util.Base64.getUrlEncoder().withoutPadding()
+                .encodeToString(raw.getBytes(java.nio.charset.StandardCharsets.UTF_8));
 
-        insertAt("agent-1", "app-a", "FIRST", "", t1);
-        insertAt("agent-1", "app-a", "SECOND", "", t2);
-        insertAt("agent-1", "app-a", "THIRD", "", t3);
-
-        List<AgentEventRecord> results = repo.query(null, null, null, null, null, 100);
-
-        assertThat(results.get(0).eventType()).isEqualTo("THIRD");
-        assertThat(results.get(1).eventType()).isEqualTo("SECOND");
-        assertThat(results.get(2).eventType()).isEqualTo("FIRST");
+        org.junit.jupiter.api.Assertions.assertThrows(
+                IllegalArgumentException.class,
+                () -> repo.queryPage(null, null, null, null, null, cursor, 10));
     }
 }

cameleer-server-core/src/main/java/com/cameleer/server/core/agent/AgentEventPage.java

@@ -0,0 +1,16 @@
+package com.cameleer.server.core.agent;
+
+import java.util.List;
+
+/**
+ * Cursor-paginated result page for agent event queries.
+ *
+ * @param data       events on this page, ordered newest-first
+ * @param nextCursor opaque cursor to pass back for the next page (null when no more)
+ * @param hasMore    whether more results exist beyond this page
+ */
+public record AgentEventPage(
+        List<AgentEventRecord> data,
+        String nextCursor,
+        boolean hasMore
+) {}

cameleer-server-core/src/main/java/com/cameleer/server/core/agent/AgentEventRepository.java

@@ -1,11 +1,16 @@
 package com.cameleer.server.core.agent;
 
 import java.time.Instant;
-import java.util.List;
 
 public interface AgentEventRepository {
 
     void insert(String instanceId, String applicationId, String environment, String eventType, String detail);
 
-    List<AgentEventRecord> query(String applicationId, String instanceId, String environment, Instant from, Instant to, int limit);
+    /**
+     * Cursor-paginated query ordered by (timestamp DESC, instance_id ASC). The cursor
+     * is an opaque base64 string produced by the implementation; pass {@code null} for
+     * the first page.
+     */
+    AgentEventPage queryPage(String applicationId, String instanceId, String environment,
+                             Instant from, Instant to, String cursor, int limit);
 }

cameleer-server-core/src/main/java/com/cameleer/server/core/agent/AgentEventService.java

@@ -4,7 +4,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.time.Instant;
-import java.util.List;
 
 public class AgentEventService {
 
@@ -21,7 +20,8 @@ public class AgentEventService {
         repository.insert(instanceId, applicationId, environment, eventType, detail);
     }
 
-    public List<AgentEventRecord> queryEvents(String applicationId, String instanceId, String environment, Instant from, Instant to, int limit) {
-        return repository.query(applicationId, instanceId, environment, from, to, limit);
+    public AgentEventPage queryEventPage(String applicationId, String instanceId, String environment,
+                                          Instant from, Instant to, String cursor, int limit) {
+        return repository.queryPage(applicationId, instanceId, environment, from, to, cursor, limit);
     }
 }

cameleer-server-core/src/main/java/com/cameleer/server/core/search/LogSearchRequest.java

@@ -7,15 +7,15 @@ import java.util.List;
  * Immutable search criteria for querying application logs.
  *
  * @param q           free-text search across message and stack trace
- * @param levels      log level filter (e.g. ["WARN","ERROR"])
+ * @param levels      log level filter (e.g. ["WARN","ERROR"]), OR-joined
  * @param application application ID filter (nullable = all apps)
  * @param instanceId  agent instance ID filter
  * @param exchangeId  Camel exchange ID filter
  * @param logger      logger name substring filter
  * @param environment optional environment filter (e.g. "dev", "staging", "prod")
- * @param source      optional source filter: "app" or "agent"
- * @param from        inclusive start of time range (required)
- * @param to          inclusive end of time range (required)
+ * @param sources     optional source filter (e.g. ["app","container","agent"]), OR-joined
+ * @param from        inclusive start of time range
+ * @param to          inclusive end of time range
  * @param cursor      ISO timestamp cursor for keyset pagination
  * @param limit       page size (1-500, default 100)
  * @param sort        sort direction: "asc" or "desc" (default "desc")
@@ -28,7 +28,7 @@ public record LogSearchRequest(
         String exchangeId,
         String logger,
         String environment,
-        String source,
+        List<String> sources,
         Instant from,
         Instant to,
         String cursor,
@@ -44,5 +44,6 @@ public record LogSearchRequest(
         if (limit > MAX_LIMIT) limit = MAX_LIMIT;
         if (sort == null || !"asc".equalsIgnoreCase(sort)) sort = "desc";
         if (levels == null) levels = List.of();
+        if (sources == null) sources = List.of();
     }
 }

docs/superpowers/specs/2026-04-17-log-filters-multiselect-infinite-scroll-design.md

@@ -0,0 +1,252 @@
+# Streaming Views: Multi-Select Filters + Infinite Scroll
+
+**Date:** 2026-04-17
+**Status:** Draft
+
+## Problem
+
+In the Runtime page's **Application Log**, the `App / Agent / Container` source buttons are single-select, and the **Level** buttons are multi-select but filtered **client-side**. Both are flawed for the same reason: when one source or level floods the result set (e.g. hundreds of INFO-level app logs), less-frequent entries (container logs, ERROR lines) can be pushed past the fetched page and never appear.
+
+The page is also a single `useQuery` that fetches at most `limit` rows. There is no way to browse older logs.
+
+The **Timeline** (agent events) has the same single-page limitation.
+
+## Goal
+
+Establish a consistent pattern for streaming views (log-like lists + event feeds):
+
+1. **Multi-select server-side filters** joined with `OR` — the server decides what's included, so no category is ever silently starved.
+2. **Infinite scroll** via cursor pagination — user scrolls down to load older entries.
+3. **Top-gated auto-refetch** — polling only runs while the user is viewing the newest entries; when they scroll away to inspect history, polling pauses so their viewport cannot shift under them.
+4. **Client-side text filter** only — text search filters pages already loaded without re-querying.
+
+Apply this pattern to:
+- `AgentHealth.tsx` — Application Log + Timeline
+- `AgentInstance.tsx` — Application Log + Timeline
+- Shared components/hooks so future streaming views reuse the same primitives.
+
+Out of scope for infinite scroll (bounded data, don't need it):
+- `LogTab.tsx` — per-exchange logs (bounded, one exchange, already capped at 500)
+- `StartupLogPanel.tsx` — container logs during a single deployment startup
+
+These two keep `useLogs` / `useStartupLogs` as-is. They will benefit automatically if `LogEntry.source` gets pushed through to `LogViewer` for badge rendering (already supported by DS).
+
+## Design
+
+### 1. Backend: multi-value `source`
+
+The log endpoint already supports comma-split `level`. Mirror that for `source`.
+
+**`cameleer-server-core/.../search/LogSearchRequest.java`**
+- Change `String source` → `List<String> sources` (default empty list).
+
+**`cameleer-server-app/.../controller/LogQueryController.java`**
+- `@RequestParam(required = false) String source` stays.
+- Parse same way as `level` (comma-split, trim, drop blanks) into `List<String>`.
+
+**`cameleer-server-app/.../search/ClickHouseLogStore.java`**
+- Replace:
+  ```
+  if (request.source() != null && !request.source().isEmpty()) {
+      baseConditions.add("source = ?");
+      baseParams.add(request.source());
+  }
+  ```
+  with a list-driven `source IN (?, ?, …)` built when `request.sources()` is non-empty.
+
+No schema change. No migration.
+
+### 2. Backend: cursor pagination for agent events
+
+Agent events currently return `List<AgentEventResponse>` with `limit` (default 50). No cursor. To support infinite scroll we need stable desc ordering + a cursor.
+
+Events have no stable ID (the ClickHouse repository synthesizes `id = 0`). The stable ordering is `(timestamp DESC, instance_id ASC)`. Cursor encodes that tuple as an opaque base64 string, matching how `ClickHouseLogStore` builds log cursors.
+
+**`cameleer-server-core/.../agent/AgentEventService.java` / `AgentEventRepository.java`**
+- Add overload `queryEvents(appId, agentId, env, from, to, cursor, limit)` returning a `AgentEventPage { data, nextCursor, hasMore }`.
+- Keep the existing un-cursored `queryEvents` if used elsewhere (audit usage; if not, delete it).
+
+**`cameleer-server-app/.../storage/ClickHouseAgentEventRepository.java`**
+- New method: on cursor, decode `(cursorTs, cursorInstance)` and add `(timestamp, instance_id) < (?, ?)` predicate.
+- Always `ORDER BY timestamp DESC, instance_id ASC`.
+- Always fetch `limit + 1` rows; last row determines `hasMore` + `nextCursor`.
+
+**`cameleer-server-app/.../controller/AgentEventsController.java`**
+- Accept optional `?cursor=`; return `AgentEventPageResponse { data, nextCursor, hasMore }` instead of a bare list.
+
+### 3. Shared UI primitives
+
+Two thin primitives. No new design-system package; live under `ui/src/components/` and `ui/src/hooks/` so they're reused from the app only.
+
+**`ui/src/hooks/useInfiniteStream.ts`** — thin `useInfiniteQuery` wrapper:
+
+```ts
+interface StreamPage<T> { data: T[]; nextCursor: string | null; hasMore: boolean }
+
+interface UseInfiniteStreamArgs<T> {
+  queryKey: unknown[];
+  fetchPage: (cursor: string | undefined) => Promise<StreamPage<T>>;
+  enabled?: boolean;
+  isAtTop: boolean;     // drives refetchInterval on/off
+  refetchMs?: number;   // default 15000
+}
+
+interface UseInfiniteStreamResult<T> {
+  items: T[];
+  fetchNextPage: () => void;
+  hasNextPage: boolean;
+  isFetchingNextPage: boolean;
+  isLoading: boolean;
+  refresh: () => void;  // invalidates and re-fetches from page 1
+}
+```
+
+Internals: wraps `useInfiniteQuery` with `getNextPageParam: (last) => last.hasMore ? last.nextCursor : undefined`, flattens pages, exposes `refresh` that calls `queryClient.invalidateQueries(queryKey)`.
+
+**`ui/src/components/InfiniteScrollArea.tsx`** — scrollable container:
+
+```tsx
+interface InfiniteScrollAreaProps {
+  onEndReached: () => void;          // call fetchNextPage
+  onTopVisibilityChange: (b: boolean) => void;
+  isFetchingNextPage: boolean;
+  hasNextPage: boolean;
+  maxHeight?: number | string;
+  children: ReactNode;
+}
+```
+
+Renders:
+```
+<div ref={scrollRef} style={{ overflowY: 'auto', maxHeight }}>
+  <div ref={topSentinelRef} />     // IntersectionObserver -> onTopVisibilityChange
+  {children}
+  <div ref={bottomSentinelRef} />  // IntersectionObserver -> onEndReached
+  {isFetchingNextPage && <Spinner />}
+  {!hasNextPage && <EndMarker />}
+</div>
+```
+
+A single `IntersectionObserver` per sentinel with `rootMargin: '100px'` for the bottom so the next page is prefetched before the user hits the literal bottom.
+
+### 4. New hooks
+
+**`ui/src/api/queries/logs.ts`**
+
+Add `useInfiniteApplicationLogs`:
+
+```ts
+export function useInfiniteApplicationLogs(args: {
+  application?: string;
+  agentId?: string;
+  sources?: string[];   // multi-select, server-side
+  levels?: string[];    // multi-select, server-side
+  exchangeId?: string;
+  isAtTop: boolean;
+}): UseInfiniteStreamResult<LogEntryResponse>
+```
+
+Under the hood: cursor-paginated calls to `/environments/{env}/logs`; `fetchPage(cursor)` sets `source=a,b`, `level=ERROR,WARN`, and time range from the global filter store.
+
+Keep `useLogs` and `useApplicationLogs` (the existing single-page wrapper) so `LogTab` and `StartupLogPanel` remain untouched. Mark `useApplicationLogs` internally as "bounded consumers only" via a short TSDoc line.
+
+**`ui/src/api/queries/agents.ts`**
+
+Add `useInfiniteAgentEvents`:
+
+```ts
+export function useInfiniteAgentEvents(args: {
+  appId?: string;
+  agentId?: string;
+  isAtTop: boolean;
+}): UseInfiniteStreamResult<AgentEventResponse>
+```
+
+Existing `useAgentEvents` is only used in `AgentHealth`/`AgentInstance` for the Timeline. It gets replaced by the new hook — no other consumers, no backwards-compat shim.
+
+### 5. Page wiring — `AgentHealth.tsx` and `AgentInstance.tsx`
+
+**Application Log block:**
+
+- State
+  - `logSources: Set<string>` (new, replaces `logSource: string`).
+  - `logLevels: Set<string>` (unchanged shape, now passed through as `levels`).
+  - `logSearch: string` (unchanged, client-side).
+  - `logSortAsc: boolean` (unchanged).
+  - `isLogAtTop: boolean` (new, from `InfiniteScrollArea`).
+
+- Data
+  - `const { items, fetchNextPage, hasNextPage, isFetchingNextPage, refresh } = useInfiniteApplicationLogs({ application: appId, agentId, sources: [...logSources], levels: [...logLevels], isAtTop: isLogAtTop });`
+
+- Map → `LogEntry[]`
+  - Same mapping as today plus `source: l.source ?? undefined` so `LogViewer`'s source badge lights up.
+
+- Client-side
+  - Text filter (`logSearch`) applied after flattening.
+  - Sort reversal (`logSortAsc`) applied after.
+
+- ButtonGroup wiring
+  - `<ButtonGroup items={LOG_SOURCE_ITEMS} value={logSources} onChange={setLogSources} />`
+  - Level `<ButtonGroup>` unchanged (`value={logLevels}`), but `onChange` now implicitly re-queries.
+  - A "Clear" button next to each group when the set is non-empty (source has 3 options; still low-cost and symmetric with level).
+
+- Layout
+  - `<LogViewer entries={filteredLogs} />` (no `maxHeight`) wrapped in `<InfiniteScrollArea maxHeight={360} ...>`.
+
+**Timeline block:**
+
+- `const { items, fetchNextPage, hasNextPage, isFetchingNextPage, refresh } = useInfiniteAgentEvents({ appId, isAtTop: isTimelineAtTop });`
+- Map to `FeedEvent[]` (same transform as today).
+- `<EventFeed events={feedEvents} />` inside `<InfiniteScrollArea>`.
+- Timeline has no filters today; none added in this spec.
+
+**Refresh buttons:**
+Both log and timeline `<RefreshCw>` buttons call `refresh()` from the stream hook. `logRefreshTo`/`eventRefreshTo` states are retired.
+
+### 6. Auto-refetch gating semantics
+
+- `InfiniteScrollArea` fires `onTopVisibilityChange(true)` when the top sentinel is fully in view, `false` when it scrolls out. Implemented via `IntersectionObserver` with threshold `1.0`.
+- `useInfiniteStream` reads `isAtTop` and sets `refetchInterval: isAtTop ? refetchMs : false`. Tanstack re-evaluates on every render, so toggling the prop takes effect on the next cycle.
+- Manual `refresh()` always works and scrolls back to top (scroll reset is owned by the page, calling `scrollRef.current?.scrollTo({ top: 0 })` after the refresh settles — wired in `AgentHealth` / `AgentInstance`).
+- No viewport-preservation logic. The contract "refetch must not move the user's viewport" is satisfied by disabling refetch while the user is scrolled away.
+
+### 7. Bounded views — minimal changes
+
+- `LogTab.tsx`: map `e.source` into the rendered `LogEntry` so source badges appear. No other changes.
+- `StartupLogPanel.tsx`: no change; startup-log rows are container-sourced by definition.
+
+### 8. OpenAPI regeneration
+
+After controller/DTO changes:
+```
+cd ui && npm run generate-api:live
+```
+Commit the resulting `openapi.json` + `schema.d.ts` in the same change. TypeScript will surface any SPA call sites that need adjustment; fix all of them before testing in the browser.
+
+### 9. `.claude/rules/` updates
+
+- `app-classes.md` — `LogQueryController` entry: add "multi-value `source` (comma-split)"; `AgentEventsController` entry: add "cursor-paginated, returns `{ data, nextCursor, hasMore }`".
+- `ui.md` — add entry for `InfiniteScrollArea` component and note the "streaming views use `useInfiniteStream` + `InfiniteScrollArea`" convention.
+
+## Testing
+
+- **Backend unit**: `ClickHouseLogStoreTest` for `source IN (...)` predicate (single, multi, empty). `ClickHouseAgentEventRepositoryTest` for cursor ordering and `hasMore` boundary.
+- **Controller**: `LogQueryControllerTest` (existing) — add `source=app,container` case. `AgentEventsControllerTest` — cursor round-trip.
+- **UI manual smoke**: scroll long log streams, mix source filters, verify auto-refetch toggles at top, confirm text filter stays local, confirm refresh resets scroll.
+
+## Risks & mitigations
+
+| Risk | Mitigation |
+|---|---|
+| Event cursor using `(timestamp, instance_id)` — collisions if two events share both | In practice events are recorded one-at-a-time per instance; tuple is stable. Tie-breaker fine as both fields are indexed. |
+| `useInfiniteQuery` refetch reloads all pages → visible flicker | Use `placeholderData: (prev) => prev` so stale data stays during refetch. Tested pattern already used by `useApplicationLogs`. |
+| IntersectionObserver on the top sentinel fires both on scroll and on list grow | Debounce via React state, not a ref — state updates coalesce per render. |
+| DS `LogViewer` may virtualize internally, hiding sentinels | `LogViewer` today has no virtualization (DS 0.1.49 props are minimal). If that changes, move sentinels into the outer scroll container (already the plan). |
+| Level client→server change breaks existing users with saved filter state | No persisted filter state exists for log levels; this is in-memory only. |
+
+## Decision log
+
+- **Server-side for source and level, client-side for text.** Confirmed during design — flooding argument applies symmetrically to source and level.
+- **Gate auto-refetch on top visibility** instead of preserving viewport. Rationale: viewport preservation requires stable row IDs (logs have timestamp collisions) and is fragile under virtualization. Gating is simple, predictable, and meets the "user never loses their line" constraint.
+- **Bounded log views (LogTab, StartupLogPanel) keep single-page hooks.** Infinite scroll isn't useful for capped data; shared primitives are available if they ever need it.
+- **Agent events get cursor pagination**, matching logs. Single-source-of-truth pattern for streaming lists.

ui/src/api/queries/agents.ts

@@ -3,6 +3,7 @@ import { config } from '../../config';
 import { useAuthStore } from '../../auth/auth-store';
 import { useEnvironmentStore } from '../environment-store';
 import { useRefreshInterval } from './use-refresh-interval';
+import { useInfiniteStream, type UseInfiniteStreamResult } from '../../hooks/useInfiniteStream';
 
 export function useAgents(status?: string, application?: string) {
   const environment = useEnvironmentStore((s) => s.environment);
@@ -31,18 +32,45 @@ export function useAgents(status?: string, application?: string) {
   });
 }
 
-export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toOverride?: string) {
+export interface AgentEventResponse {
+  id: number;
+  instanceId: string;
+  applicationId: string;
+  eventType: string;
+  detail: string;
+  timestamp: string;
+}
+
+interface AgentEventPageResponse {
+  data: AgentEventResponse[];
+  nextCursor: string | null;
+  hasMore: boolean;
+}
+
+export interface UseInfiniteAgentEventsArgs {
+  appId?: string;
+  agentId?: string;
+  isAtTop: boolean;
+  pageSize?: number;
+}
+
+export function useInfiniteAgentEvents(
+  args: UseInfiniteAgentEventsArgs,
+): UseInfiniteStreamResult<AgentEventResponse> {
   const environment = useEnvironmentStore((s) => s.environment);
-  const refetchInterval = useRefreshInterval(15_000);
-  return useQuery({
-    queryKey: ['agents', 'events', environment, appId, agentId, limit, toOverride],
-    queryFn: async () => {
+  const pageSize = args.pageSize ?? 50;
+
+  return useInfiniteStream<AgentEventResponse>({
+    queryKey: ['agents', 'events', 'infinite', environment ?? '', args.appId ?? '', args.agentId ?? '', pageSize],
+    enabled: !!environment,
+    isAtTop: args.isAtTop,
+    fetchPage: async (cursor) => {
       const token = useAuthStore.getState().accessToken;
       const params = new URLSearchParams();
-      if (appId) params.set('appId', appId);
-      if (agentId) params.set('agentId', agentId);
-      if (toOverride) params.set('to', toOverride);
-      params.set('limit', String(limit));
+      if (args.appId) params.set('appId', args.appId);
+      if (args.agentId) params.set('agentId', args.agentId);
+      if (cursor) params.set('cursor', cursor);
+      params.set('limit', String(pageSize));
       const res = await fetch(
         `${config.apiBaseUrl}/environments/${encodeURIComponent(environment!)}/agents/events?${params}`,
         {
@@ -52,9 +80,8 @@ export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toO
           },
         });
       if (!res.ok) throw new Error('Failed to load agent events');
-      return res.json();
+      const page: AgentEventPageResponse = await res.json();
+      return { data: page.data, nextCursor: page.nextCursor, hasMore: page.hasMore };
     },
-    enabled: !!environment,
-    refetchInterval,
   });
 }

ui/src/api/queries/logs.ts

@@ -4,6 +4,7 @@ import { useAuthStore } from '../../auth/auth-store';
 import { useRefreshInterval } from './use-refresh-interval';
 import { useGlobalFilters } from '@cameleer/design-system';
 import { useEnvironmentStore } from '../environment-store';
+import { useInfiniteStream, type UseInfiniteStreamResult } from '../../hooks/useInfiniteStream';
 
 export interface LogEntryResponse {
   timestamp: string;
@@ -157,3 +158,82 @@ export function useStartupLogs(
     refetchInterval: isStarting ? 3_000 : false,
   });
 }
+
+export interface UseInfiniteApplicationLogsArgs {
+  application?: string;
+  agentId?: string;
+  sources?: string[];   // multi-select, server-side OR
+  levels?: string[];    // multi-select, server-side OR
+  exchangeId?: string;
+  sort?: 'asc' | 'desc';
+  isAtTop: boolean;
+  pageSize?: number;
+}
+
+/**
+ * Cursor-paginated log stream. Filters `sources`, `levels`, and the global
+ * time range are applied server-side. Free-text search is applied by the
+ * caller on top of the flattened items.
+ */
+export function useInfiniteApplicationLogs(
+  args: UseInfiniteApplicationLogsArgs,
+): UseInfiniteStreamResult<LogEntryResponse> {
+  const { timeRange } = useGlobalFilters();
+  const selectedEnv = useEnvironmentStore((s) => s.environment);
+
+  const useTimeRange = !args.exchangeId;
+  const fromIso = useTimeRange ? timeRange.start.toISOString() : undefined;
+  const toIso = useTimeRange ? timeRange.end.toISOString() : undefined;
+
+  const sortedSources = (args.sources ?? []).slice().sort();
+  const sortedLevels = (args.levels ?? []).slice().sort();
+  const sourcesParam = sortedSources.join(',');
+  const levelsParam = sortedLevels.join(',');
+  const pageSize = args.pageSize ?? 100;
+  const sort = args.sort ?? 'desc';
+
+  return useInfiniteStream<LogEntryResponse>({
+    queryKey: [
+      'logs', 'infinite',
+      selectedEnv ?? '',
+      args.application ?? '',
+      args.agentId ?? '',
+      args.exchangeId ?? '',
+      sourcesParam,
+      levelsParam,
+      fromIso ?? '',
+      toIso ?? '',
+      pageSize,
+      sort,
+    ],
+    enabled: !!args.application && !!selectedEnv,
+    isAtTop: args.isAtTop,
+    fetchPage: async (cursor) => {
+      const token = useAuthStore.getState().accessToken;
+      const qp = new URLSearchParams();
+      if (args.application) qp.set('application', args.application);
+      if (args.agentId) qp.set('agentId', args.agentId);
+      if (args.exchangeId) qp.set('exchangeId', args.exchangeId);
+      if (sourcesParam) qp.set('source', sourcesParam);
+      if (levelsParam) qp.set('level', levelsParam);
+      if (fromIso) qp.set('from', fromIso);
+      if (toIso) qp.set('to', toIso);
+      if (cursor) qp.set('cursor', cursor);
+      qp.set('limit', String(pageSize));
+      qp.set('sort', sort);
+
+      const res = await fetch(
+        `${config.apiBaseUrl}/environments/${encodeURIComponent(selectedEnv ?? '')}/logs?${qp}`,
+        {
+          headers: {
+            Authorization: `Bearer ${token}`,
+            'X-Cameleer-Protocol-Version': '1',
+          },
+        },
+      );
+      if (!res.ok) throw new Error('Failed to load logs');
+      const page: LogSearchPageResponse = await res.json();
+      return { data: page.data, nextCursor: page.nextCursor, hasMore: page.hasMore };
+    },
+  });
+}

ui/src/api/schema.d.ts

@@ -1395,7 +1395,7 @@ export interface paths {
         };
         /**
          * Query agent events in this environment
-         * @description Returns agent lifecycle events, optionally filtered by app and/or agent ID
+         * @description Cursor-paginated. Returns newest first. Pass nextCursor back as ?cursor= for the next page.
          */
         get: operations["getEvents"];
         put?: never;
@@ -2309,6 +2309,7 @@ export interface components {
             routeId: string;
             instanceId: string;
             applicationId: string;
+            environment: string;
             status: string;
             /** Format: date-time */
             startTime: string;
@@ -2641,6 +2642,12 @@ export interface components {
             /** Format: double */
             value: number;
         };
+        /** @description Cursor-paginated agent event list */
+        AgentEventPageResponse: {
+            data?: components["schemas"]["AgentEventResponse"][];
+            nextCursor?: string;
+            hasMore?: boolean;
+        };
         /** @description Agent lifecycle event */
         AgentEventResponse: {
             /** Format: int64 */
@@ -6058,6 +6065,7 @@ export interface operations {
                 agentId?: string;
                 from?: string;
                 to?: string;
+                cursor?: string;
                 limit?: number;
             };
             header?: never;
@@ -6066,13 +6074,13 @@ export interface operations {
         };
         requestBody?: never;
         responses: {
-            /** @description Events returned */
+            /** @description Event page returned */
             200: {
                 headers: {
                     [name: string]: unknown;
                 };
                 content: {
-                    "*/*": components["schemas"]["AgentEventResponse"][];
+                    "*/*": components["schemas"]["AgentEventPageResponse"];
                 };
             };
         };

ui/src/components/ExecutionDiagram/tabs/LogTab.tsx

@@ -57,6 +57,7 @@ export function LogTab({ applicationId, exchangeId, processorId }: LogTabProps)
       timestamp: e.timestamp ?? '',
       level: mapLogLevel(e.level),
       message: e.message ?? '',
+      source: e.source ?? undefined,
     }));
   }, [logPage, processorId, filter]);
 

ui/src/components/InfiniteScrollArea.module.css

@@ -0,0 +1,22 @@
+.scrollArea {
+  overflow-y: auto;
+  position: relative;
+}
+
+.sentinel {
+  height: 1px;
+  width: 100%;
+  pointer-events: none;
+}
+
+.loadingMore,
+.endOfStream {
+  padding: 8px 12px;
+  font-size: 11px;
+  color: var(--text-muted);
+  text-align: center;
+}
+
+.endOfStream {
+  opacity: 0.5;
+}

ui/src/components/InfiniteScrollArea.tsx

@@ -0,0 +1,80 @@
+import { useEffect, useRef, type ReactNode, type RefObject } from 'react';
+import styles from './InfiniteScrollArea.module.css';
+
+export interface InfiniteScrollAreaProps {
+  onEndReached: () => void;
+  onTopVisibilityChange?: (atTop: boolean) => void;
+  isFetchingNextPage: boolean;
+  hasNextPage: boolean;
+  isLoading?: boolean;
+  hasItems?: boolean;
+  maxHeight?: number | string;
+  children: ReactNode;
+  /** Optional caller-owned scroll container ref (e.g. for scroll-to-top on refresh). */
+  scrollRef?: RefObject<HTMLDivElement | null>;
+  className?: string;
+}
+
+export function InfiniteScrollArea({
+  onEndReached,
+  onTopVisibilityChange,
+  isFetchingNextPage,
+  hasNextPage,
+  isLoading = false,
+  hasItems = true,
+  maxHeight = 360,
+  children,
+  scrollRef,
+  className,
+}: InfiniteScrollAreaProps) {
+  const internalRef = useRef<HTMLDivElement | null>(null);
+  const containerRef = scrollRef ?? internalRef;
+  const topSentinel = useRef<HTMLDivElement | null>(null);
+  const bottomSentinel = useRef<HTMLDivElement | null>(null);
+
+  useEffect(() => {
+    if (!onTopVisibilityChange) return;
+    const root = containerRef.current;
+    const target = topSentinel.current;
+    if (!root || !target) return;
+    const obs = new IntersectionObserver(
+      (entries) => {
+        for (const e of entries) onTopVisibilityChange(e.isIntersecting);
+      },
+      { root, threshold: 1.0 },
+    );
+    obs.observe(target);
+    return () => obs.disconnect();
+  }, [containerRef, onTopVisibilityChange]);
+
+  useEffect(() => {
+    if (!hasNextPage) return;
+    const root = containerRef.current;
+    const target = bottomSentinel.current;
+    if (!root || !target) return;
+    const obs = new IntersectionObserver(
+      (entries) => {
+        for (const e of entries) if (e.isIntersecting) onEndReached();
+      },
+      { root, rootMargin: '100px', threshold: 0 },
+    );
+    obs.observe(target);
+    return () => obs.disconnect();
+  }, [containerRef, onEndReached, hasNextPage]);
+
+  return (
+    <div
+      ref={containerRef}
+      className={`${styles.scrollArea}${className ? ` ${className}` : ''}`}
+      style={{ maxHeight }}
+    >
+      <div ref={topSentinel} className={styles.sentinel} aria-hidden="true" />
+      {children}
+      <div ref={bottomSentinel} className={styles.sentinel} aria-hidden="true" />
+      {isFetchingNextPage && <div className={styles.loadingMore}>Loading more…</div>}
+      {!hasNextPage && !isLoading && hasItems && (
+        <div className={styles.endOfStream}>End of stream</div>
+      )}
+    </div>
+  );
+}

ui/src/hooks/useInfiniteStream.ts

@@ -0,0 +1,71 @@
+import { useInfiniteQuery, useQueryClient } from '@tanstack/react-query';
+import { useCallback, useMemo } from 'react';
+
+export interface StreamPage<T> {
+  data: T[];
+  nextCursor: string | null;
+  hasMore: boolean;
+}
+
+export interface UseInfiniteStreamArgs<T> {
+  queryKey: readonly unknown[];
+  fetchPage: (cursor: string | undefined) => Promise<StreamPage<T>>;
+  enabled?: boolean;
+  /** When true, the query auto-refetches every refetchMs ms. When false, polling pauses. */
+  isAtTop: boolean;
+  refetchMs?: number;
+  staleTime?: number;
+}
+
+export interface UseInfiniteStreamResult<T> {
+  items: T[];
+  fetchNextPage: () => void;
+  hasNextPage: boolean;
+  isFetchingNextPage: boolean;
+  isLoading: boolean;
+  refresh: () => void;
+}
+
+/**
+ * Thin wrapper over tanstack useInfiniteQuery that:
+ *   - flattens pages into a single items[] array (newest first)
+ *   - gates auto-refetch on isAtTop (so a user scrolled down does not lose their viewport)
+ *   - exposes refresh() that invalidates the query (reset to page 1 on next render)
+ */
+export function useInfiniteStream<T>(args: UseInfiniteStreamArgs<T>): UseInfiniteStreamResult<T> {
+  const { queryKey, fetchPage, enabled = true, isAtTop, refetchMs = 15_000, staleTime = 300 } = args;
+  const queryClient = useQueryClient();
+
+  const query = useInfiniteQuery<StreamPage<T>, Error>({
+    queryKey: [...queryKey],
+    initialPageParam: undefined as string | undefined,
+    queryFn: ({ pageParam }) => fetchPage(pageParam as string | undefined),
+    getNextPageParam: (last) => (last.hasMore && last.nextCursor ? last.nextCursor : undefined),
+    enabled,
+    refetchInterval: isAtTop ? refetchMs : false,
+    staleTime,
+    placeholderData: (prev) => prev,
+  });
+
+  const items = useMemo<T[]>(
+    () => (query.data?.pages ?? []).flatMap((p) => p.data),
+    [query.data],
+  );
+
+  const fetchNextPage = useCallback(() => {
+    if (query.hasNextPage && !query.isFetchingNextPage) query.fetchNextPage();
+  }, [query.hasNextPage, query.isFetchingNextPage, query.fetchNextPage]);
+
+  const refresh = useCallback(() => {
+    queryClient.invalidateQueries({ queryKey: [...queryKey] });
+  }, [queryClient, queryKey]);
+
+  return {
+    items,
+    fetchNextPage,
+    hasNextPage: !!query.hasNextPage,
+    isFetchingNextPage: query.isFetchingNextPage,
+    isLoading: query.isLoading,
+    refresh,
+  };
+}

ui/src/pages/AgentHealth/AgentHealth.tsx

@@ -11,8 +11,10 @@ import type { Column, FeedEvent, LogEntry, ButtonGroupItem } from '@cameleer/des
 import styles from './AgentHealth.module.css';
 import sectionStyles from '../../styles/section-card.module.css';
 import logStyles from '../../styles/log-panel.module.css';
-import { useAgents, useAgentEvents } from '../../api/queries/agents';
-import { useApplicationLogs } from '../../api/queries/logs';
+import { useAgents } from '../../api/queries/agents';
+import { useInfiniteApplicationLogs } from '../../api/queries/logs';
+import { useInfiniteAgentEvents } from '../../api/queries/agents';
+import { InfiniteScrollArea } from '../../components/InfiniteScrollArea';
 import { useApplicationConfig, useUpdateApplicationConfig } from '../../api/queries/commands';
 import { useCatalog, useDismissApp } from '../../api/queries/catalog';
 import { useIsAdmin } from '../../auth/auth-store';
@@ -281,8 +283,9 @@ export default function AgentHealth() {
     });
   }, [appConfig, configDraft, updateConfig, toast, appId]);
   const [eventSortAsc, setEventSortAsc] = useState(false);
-  const [eventRefreshTo, setEventRefreshTo] = useState<string | undefined>();
-  const { data: events } = useAgentEvents(appId, undefined, 50, eventRefreshTo);
+  const [isTimelineAtTop, setIsTimelineAtTop] = useState(true);
+  const timelineScrollRef = useRef<HTMLDivElement | null>(null);
+  const eventStream = useInfiniteAgentEvents({ appId, isAtTop: isTimelineAtTop });
 
   const [appFilter, setAppFilter] = useState('');
   type AppSortKey = 'status' | 'name' | 'tps' | 'cpu' | 'heartbeat';
@@ -300,22 +303,30 @@ export default function AgentHealth() {
 
   const [logSearch, setLogSearch] = useState('');
   const [logLevels, setLogLevels] = useState<Set<string>>(new Set());
-  const [logSource, setLogSource] = useState<string>('');  // '' = all, 'app', 'agent'
+  const [logSources, setLogSources] = useState<Set<string>>(new Set());
   const [logSortAsc, setLogSortAsc] = useState(false);
-  const [logRefreshTo, setLogRefreshTo] = useState<string | undefined>();
-  const { data: rawLogs } = useApplicationLogs(appId, undefined, { toOverride: logRefreshTo, source: logSource || undefined });
+  const [isLogAtTop, setIsLogAtTop] = useState(true);
+  const logScrollRef = useRef<HTMLDivElement | null>(null);
+
+  const logStream = useInfiniteApplicationLogs({
+    application: appId,
+    sources: [...logSources],
+    levels: [...logLevels],
+    sort: logSortAsc ? 'asc' : 'desc',
+    isAtTop: isLogAtTop,
+  });
   const logEntries = useMemo<LogEntry[]>(() => {
-    const mapped = (rawLogs || []).map((l) => ({
+    return logStream.items.map((l) => ({
       timestamp: l.timestamp ?? '',
       level: mapLogLevel(l.level),
       message: l.message ?? '',
+      source: l.source ?? undefined,
     }));
-    return logSortAsc ? mapped.toReversed() : mapped;
-  }, [rawLogs, logSortAsc]);
+  }, [logStream.items]);
   const logSearchLower = logSearch.toLowerCase();
-  const filteredLogs = logEntries
-    .filter((l) => logLevels.size === 0 || logLevels.has(l.level))
-    .filter((l) => !logSearchLower || l.message.toLowerCase().includes(logSearchLower));
+  const filteredLogs = logSearchLower
+    ? logEntries.filter((l) => l.message.toLowerCase().includes(logSearchLower))
+    : logEntries;
 
   const agentList = agents ?? [];
 
@@ -359,15 +370,15 @@ export default function AgentHealth() {
 
   // Map events to FeedEvent
   const feedEvents: FeedEvent[] = useMemo(() => {
-    const mapped = (events ?? []).map((e: { id: number; instanceId: string; eventType: string; detail: string; timestamp: string }) => ({
-      id: String(e.id),
+    const mapped = eventStream.items.map((e) => ({
+      id: `${e.timestamp}:${e.instanceId}:${e.eventType}`,
       severity: eventSeverity(e.eventType),
       icon: eventIcon(e.eventType),
       message: `${e.instanceId}: ${e.eventType}${e.detail ? ' \u2014 ' + e.detail : ''}`,
       timestamp: new Date(e.timestamp),
     }));
     return eventSortAsc ? mapped.toReversed() : mapped;
-  }, [events, eventSortAsc]);
+  }, [eventStream.items, eventSortAsc]);
 
   // Column definitions for the instance DataTable
   const instanceColumns: Column<AgentInstance>[] = useMemo(
@@ -890,11 +901,18 @@ export default function AgentHealth() {
           <div className={logStyles.logHeader}>
             <SectionHeader>Application Log</SectionHeader>
             <div className={logStyles.headerActions}>
-              <span className={styles.sectionMeta}>{logEntries.length} entries</span>
+              <span className={styles.sectionMeta}>
+                {filteredLogs.length === logStream.items.length
+                  ? `${filteredLogs.length} entries`
+                  : `${filteredLogs.length} of ${logStream.items.length} entries`}
+              </span>
               <Button variant="ghost" size="sm" onClick={() => setLogSortAsc((v) => !v)} title={logSortAsc ? 'Oldest first' : 'Newest first'}>
                 {logSortAsc ? '\u2191' : '\u2193'}
               </Button>
-              <Button variant="ghost" size="sm" onClick={() => setLogRefreshTo(new Date().toISOString())} title="Refresh">
+              <Button variant="ghost" size="sm" onClick={() => {
+                logStream.refresh();
+                logScrollRef.current?.scrollTo({ top: 0 });
+              }} title="Refresh">
                 <RefreshCw size={14} />
               </Button>
             </div>
@@ -922,9 +940,14 @@ export default function AgentHealth() {
             </div>
             <ButtonGroup
               items={LOG_SOURCE_ITEMS}
-              value={logSource ? new Set([logSource]) : new Set()}
-              onChange={(v) => setLogSource(v.size === 0 ? '' : [...v][0])}
+              value={logSources}
+              onChange={setLogSources}
             />
+            {logSources.size > 0 && (
+              <Button variant="ghost" size="sm" onClick={() => setLogSources(new Set())}>
+                Clear
+              </Button>
+            )}
             <ButtonGroup items={LOG_LEVEL_ITEMS} value={logLevels} onChange={setLogLevels} />
             {logLevels.size > 0 && (
               <Button variant="ghost" size="sm" onClick={() => setLogLevels(new Set())}>
@@ -932,33 +955,62 @@ export default function AgentHealth() {
               </Button>
             )}
           </div>
-          {filteredLogs.length > 0 ? (
-            <LogViewer entries={filteredLogs} maxHeight={360} />
-          ) : (
-            <div className={logStyles.logEmpty}>
-              {logSearch || logLevels.size > 0 ? 'No matching log entries' : 'No log entries available'}
-            </div>
-          )}
+          <InfiniteScrollArea
+            scrollRef={logScrollRef}
+            onEndReached={logStream.fetchNextPage}
+            onTopVisibilityChange={setIsLogAtTop}
+            isFetchingNextPage={logStream.isFetchingNextPage}
+            hasNextPage={logStream.hasNextPage}
+            isLoading={logStream.isLoading}
+            hasItems={logStream.items.length > 0}
+            maxHeight={360}
+          >
+            {filteredLogs.length > 0 ? (
+              <LogViewer entries={filteredLogs} />
+            ) : (
+              <div className={logStyles.logEmpty}>
+                {logSearch || logLevels.size > 0 || logSources.size > 0
+                  ? 'No matching log entries'
+                  : logStream.isLoading ? 'Loading logs\u2026' : 'No log entries available'}
+              </div>
+            )}
+          </InfiniteScrollArea>
         </div>
 
         <div className={`${sectionStyles.section} ${styles.eventCard}`}>
           <div className={styles.eventCardHeader}>
             <span className={styles.sectionTitle}>Timeline</span>
             <div className={logStyles.headerActions}>
-              <span className={styles.sectionMeta}>{feedEvents.length} events</span>
+              <span className={styles.sectionMeta}>{eventStream.items.length} events</span>
               <Button variant="ghost" size="sm" onClick={() => setEventSortAsc((v) => !v)} title={eventSortAsc ? 'Oldest first' : 'Newest first'}>
                 {eventSortAsc ? '\u2191' : '\u2193'}
               </Button>
-              <Button variant="ghost" size="sm" onClick={() => setEventRefreshTo(new Date().toISOString())} title="Refresh">
+              <Button variant="ghost" size="sm" onClick={() => {
+                eventStream.refresh();
+                timelineScrollRef.current?.scrollTo({ top: 0 });
+              }} title="Refresh">
                 <RefreshCw size={14} />
               </Button>
             </div>
           </div>
-          {feedEvents.length > 0 ? (
-            <EventFeed events={feedEvents} maxItems={100} />
-          ) : (
-            <div className={logStyles.logEmpty}>No events in the selected time range.</div>
-          )}
+          <InfiniteScrollArea
+            scrollRef={timelineScrollRef}
+            onEndReached={eventStream.fetchNextPage}
+            onTopVisibilityChange={setIsTimelineAtTop}
+            isFetchingNextPage={eventStream.isFetchingNextPage}
+            hasNextPage={eventStream.hasNextPage}
+            isLoading={eventStream.isLoading}
+            hasItems={eventStream.items.length > 0}
+            maxHeight={360}
+          >
+            {feedEvents.length > 0 ? (
+              <EventFeed events={feedEvents} />
+            ) : (
+              <div className={logStyles.logEmpty}>
+                {eventStream.isLoading ? 'Loading events\u2026' : 'No events in the selected time range.'}
+              </div>
+            )}
+          </InfiniteScrollArea>
         </div>
       </div>
 

ui/src/pages/AgentInstance/AgentInstance.tsx

@@ -1,6 +1,9 @@
-import { useMemo, useState } from 'react';
+import { useMemo, useRef, useState } from 'react';
 import { useParams } from 'react-router';
 import { RefreshCw } from 'lucide-react';
+import { useInfiniteApplicationLogs } from '../../api/queries/logs';
+import { useInfiniteAgentEvents } from '../../api/queries/agents';
+import { InfiniteScrollArea } from '../../components/InfiniteScrollArea';
 import {
   StatCard, StatusDot, Badge, ThemedChart, Line, Area, ReferenceLine, CHART_COLORS,
   EventFeed, Spinner, EmptyState, SectionHeader, MonoText,
@@ -11,8 +14,7 @@ import styles from './AgentInstance.module.css';
 import sectionStyles from '../../styles/section-card.module.css';
 import logStyles from '../../styles/log-panel.module.css';
 import chartCardStyles from '../../styles/chart-card.module.css';
-import { useAgents, useAgentEvents } from '../../api/queries/agents';
-import { useApplicationLogs } from '../../api/queries/logs';
+import { useAgents } from '../../api/queries/agents';
 import { useAgentMetrics } from '../../api/queries/agent-metrics';
 import { formatUptime, mapLogLevel, eventSeverity, eventIcon } from '../../utils/agent-utils';
 import { useEnvironmentStore } from '../../api/environment-store';
@@ -36,17 +38,19 @@ export default function AgentInstance() {
   const { timeRange } = useGlobalFilters();
   const [logSearch, setLogSearch] = useState('');
   const [logLevels, setLogLevels] = useState<Set<string>>(new Set());
-  const [logSource, setLogSource] = useState<string>('');  // '' = all, 'app', 'agent'
+  const [logSources, setLogSources] = useState<Set<string>>(new Set());
   const [logSortAsc, setLogSortAsc] = useState(false);
   const [eventSortAsc, setEventSortAsc] = useState(false);
-  const [logRefreshTo, setLogRefreshTo] = useState<string | undefined>();
-  const [eventRefreshTo, setEventRefreshTo] = useState<string | undefined>();
+  const [isLogAtTop, setIsLogAtTop] = useState(true);
+  const [isTimelineAtTop, setIsTimelineAtTop] = useState(true);
+  const logScrollRef = useRef<HTMLDivElement | null>(null);
+  const timelineScrollRef = useRef<HTMLDivElement | null>(null);
   const timeFrom = timeRange.start.toISOString();
   const timeTo = timeRange.end.toISOString();
 
   const selectedEnv = useEnvironmentStore((s) => s.environment);
   const { data: agents, isLoading } = useAgents(undefined, appId);
-  const { data: events } = useAgentEvents(appId, instanceId, 50, eventRefreshTo);
+  const eventStream = useInfiniteAgentEvents({ appId, agentId: instanceId, isAtTop: isTimelineAtTop });
 
   const agent = useMemo(
     () => (agents || []).find((a: any) => a.instanceId === instanceId) as any,
@@ -80,17 +84,17 @@ export default function AgentInstance() {
   );
 
   const feedEvents = useMemo<FeedEvent[]>(() => {
-    const mapped = (events || [])
-      .filter((e: any) => !instanceId || e.instanceId === instanceId)
-      .map((e: any) => ({
-        id: String(e.id),
+    const mapped = eventStream.items
+      .filter((e) => !instanceId || e.instanceId === instanceId)
+      .map((e) => ({
+        id: `${e.timestamp}:${e.instanceId}:${e.eventType}`,
         severity: eventSeverity(e.eventType),
         icon: eventIcon(e.eventType),
         message: `${e.eventType}${e.detail ? ' \u2014 ' + e.detail : ''}`,
         timestamp: new Date(e.timestamp),
       }));
     return eventSortAsc ? mapped.toReversed() : mapped;
-  }, [events, instanceId, eventSortAsc]);
+  }, [eventStream.items, instanceId, eventSortAsc]);
 
   const formatTime = (t: string) =>
     new Date(t).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
@@ -132,19 +136,26 @@ export default function AgentInstance() {
   }, [agentMetrics]);
 
   // Application logs
-  const { data: rawLogs } = useApplicationLogs(appId, instanceId, { toOverride: logRefreshTo, source: logSource || undefined });
+  const logStream = useInfiniteApplicationLogs({
+    application: appId,
+    agentId: instanceId,
+    sources: [...logSources],
+    levels: [...logLevels],
+    sort: logSortAsc ? 'asc' : 'desc',
+    isAtTop: isLogAtTop,
+  });
   const logEntries = useMemo<LogEntry[]>(() => {
-    const mapped = (rawLogs || []).map((l) => ({
+    return logStream.items.map((l) => ({
       timestamp: l.timestamp ?? '',
       level: mapLogLevel(l.level),
       message: l.message ?? '',
+      source: l.source ?? undefined,
     }));
-    return logSortAsc ? mapped.toReversed() : mapped;
-  }, [rawLogs, logSortAsc]);
+  }, [logStream.items]);
   const searchLower = logSearch.toLowerCase();
-  const filteredLogs = logEntries
-    .filter((l) => logLevels.size === 0 || logLevels.has(l.level))
-    .filter((l) => !searchLower || l.message.toLowerCase().includes(searchLower));
+  const filteredLogs = searchLower
+    ? logEntries.filter((l) => l.message.toLowerCase().includes(searchLower))
+    : logEntries;
 
   if (isLoading) return <Spinner size="lg" />;
 
@@ -396,11 +407,18 @@ export default function AgentInstance() {
           <div className={logStyles.logHeader}>
             <SectionHeader>Application Log</SectionHeader>
             <div className={logStyles.headerActions}>
-              <span className={styles.chartMeta}>{logEntries.length} entries</span>
+              <span className={styles.chartMeta}>
+                {filteredLogs.length === logStream.items.length
+                  ? `${filteredLogs.length} entries`
+                  : `${filteredLogs.length} of ${logStream.items.length} entries`}
+              </span>
               <button className={logStyles.sortBtn} onClick={() => setLogSortAsc((v) => !v)} title={logSortAsc ? 'Oldest first' : 'Newest first'}>
                 {logSortAsc ? '\u2191' : '\u2193'}
               </button>
-              <button className={logStyles.refreshBtn} onClick={() => setLogRefreshTo(new Date().toISOString())} title="Refresh">
+              <button className={logStyles.refreshBtn} onClick={() => {
+                logStream.refresh();
+                logScrollRef.current?.scrollTo({ top: 0 });
+              }} title="Refresh">
                 <RefreshCw size={14} />
               </button>
             </div>
@@ -428,9 +446,14 @@ export default function AgentInstance() {
             </div>
             <ButtonGroup
               items={LOG_SOURCE_ITEMS}
-              value={logSource ? new Set([logSource]) : new Set()}
-              onChange={(v) => setLogSource(v.size === 0 ? '' : [...v][0])}
+              value={logSources}
+              onChange={setLogSources}
             />
+            {logSources.size > 0 && (
+              <button className={logStyles.logClearFilters} onClick={() => setLogSources(new Set())}>
+                Clear
+              </button>
+            )}
             <ButtonGroup items={LOG_LEVEL_ITEMS} value={logLevels} onChange={setLogLevels} />
             {logLevels.size > 0 && (
               <button className={logStyles.logClearFilters} onClick={() => setLogLevels(new Set())}>
@@ -438,33 +461,62 @@ export default function AgentInstance() {
               </button>
             )}
           </div>
-          {filteredLogs.length > 0 ? (
-            <LogViewer entries={filteredLogs} maxHeight={360} />
-          ) : (
-            <div className={logStyles.logEmpty}>
-              {logSearch || logLevels.size > 0 ? 'No matching log entries' : 'No log entries available'}
-            </div>
-          )}
+          <InfiniteScrollArea
+            scrollRef={logScrollRef}
+            onEndReached={logStream.fetchNextPage}
+            onTopVisibilityChange={setIsLogAtTop}
+            isFetchingNextPage={logStream.isFetchingNextPage}
+            hasNextPage={logStream.hasNextPage}
+            isLoading={logStream.isLoading}
+            hasItems={logStream.items.length > 0}
+            maxHeight={360}
+          >
+            {filteredLogs.length > 0 ? (
+              <LogViewer entries={filteredLogs} />
+            ) : (
+              <div className={logStyles.logEmpty}>
+                {logSearch || logLevels.size > 0 || logSources.size > 0
+                  ? 'No matching log entries'
+                  : logStream.isLoading ? 'Loading logs…' : 'No log entries available'}
+              </div>
+            )}
+          </InfiniteScrollArea>
         </div>
 
         <div className={`${sectionStyles.section} ${styles.timelineCard}`}>
           <div className={styles.timelineHeader}>
             <span className={styles.chartTitle}>Timeline</span>
             <div className={logStyles.headerActions}>
-              <span className={styles.chartMeta}>{feedEvents.length} events</span>
+              <span className={styles.chartMeta}>{eventStream.items.length} events</span>
               <button className={logStyles.sortBtn} onClick={() => setEventSortAsc((v) => !v)} title={eventSortAsc ? 'Oldest first' : 'Newest first'}>
                 {eventSortAsc ? '\u2191' : '\u2193'}
               </button>
-              <button className={logStyles.refreshBtn} onClick={() => setEventRefreshTo(new Date().toISOString())} title="Refresh">
+              <button className={logStyles.refreshBtn} onClick={() => {
+                eventStream.refresh();
+                timelineScrollRef.current?.scrollTo({ top: 0 });
+              }} title="Refresh">
                 <RefreshCw size={14} />
               </button>
             </div>
           </div>
-          {feedEvents.length > 0 ? (
-            <EventFeed events={feedEvents} maxItems={50} />
-          ) : (
-            <div className={logStyles.logEmpty}>No events in the selected time range.</div>
-          )}
+          <InfiniteScrollArea
+            scrollRef={timelineScrollRef}
+            onEndReached={eventStream.fetchNextPage}
+            onTopVisibilityChange={setIsTimelineAtTop}
+            isFetchingNextPage={eventStream.isFetchingNextPage}
+            hasNextPage={eventStream.hasNextPage}
+            isLoading={eventStream.isLoading}
+            hasItems={eventStream.items.length > 0}
+            maxHeight={360}
+          >
+            {feedEvents.length > 0 ? (
+              <EventFeed events={feedEvents} />
+            ) : (
+              <div className={logStyles.logEmpty}>
+                {eventStream.isLoading ? 'Loading events…' : 'No events in the selected time range.'}
+              </div>
+            )}
+          </InfiniteScrollArea>
         </div>
       </div>
     </div>