flynn/.planning/phases/03-live-ops-dashboard/03-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	duration	completed
03-live-ops-dashboard	01	gateway	metrics ring-buffer rpc health-endpoint monitoring	phase provides 01-daemon-decomposition GatewayServer, LaneQueue, handler architecture, session bridge	MetricsCollector class with counters, model call ring buffer, event ring buffer, active request tracking system.metrics, system.events, system.activeRequests RPC handlers GET /health unauthenticated HTTP endpoint Metrics recording wired into agent.send request flow	03-02-PLAN (dashboard UI consumes these RPC methods)	added patterns ring-buffer with FIFO eviction optional-chaining metrics injection gauge counters	created modified src/gateway/metrics.ts src/gateway/metrics.test.ts src/gateway/server.ts src/gateway/handlers/system.ts src/gateway/handlers/agent.ts src/gateway/lane-queue.ts	MetricsCollector created inside GatewayServer constructor (self-contained, no services.ts changes needed) Ring buffers: 200 model calls, 500 events — reasonable for dashboard display without unbounded growth Metrics passed to agent handler as optional MetricsCollector instance (not individual callbacks) startRequest called before laneQueue.enqueue, endRequest in finally block — tracks full queuing + execution time	Optional metrics injection: deps.metrics?.method() pattern for zero-cost when metrics disabled Ring buffer with shift() eviction for bounded memory in long-running daemon Unauthenticated /health endpoint before auth check for Docker HEALTHCHECK compatibility	2min	2026-02-10

Phase 3 Plan 1: Metrics Collection Backend Summary

MetricsCollector with counters, ring buffers, and active request tracking, exposed via 3 RPC handlers and /health HTTP endpoint, wired into agent.send flow

Performance

• Duration: ~2 min
• Started: 2026-02-10T05:27:59Z
• Completed: 2026-02-10T05:29:33Z
• Tasks: 2/2
• Files modified: 6

Accomplishments

• MetricsCollector class tracking messages processed, errors, active requests, model call latency, and event stream
• Three new RPC handlers (system.metrics, system.events, system.activeRequests) for dashboard consumption
• GET /health unauthenticated endpoint returning JSON status for Docker HEALTHCHECK
• Agent request flow records metrics: message counts, error events, tool failure events, active request tracking

Task Commits

Each task was committed atomically:

1. Task 1: Create MetricsCollector and wire into gateway - bd1880a (feat)
2. Task 2: Hook metrics recording into agent request flow - a0feff9 (feat)

Files Created/Modified

• src/gateway/metrics.ts - MetricsCollector class with counters, ring buffers, active request map, snapshot method
• src/gateway/metrics.test.ts - 20 tests covering counters, ring buffer limits, event filtering, active request tracking, snapshot shape
• src/gateway/server.ts - MetricsCollector creation in constructor, /health HTTP endpoint, metrics callbacks to handlers
• src/gateway/handlers/system.ts - system.metrics, system.events, system.activeRequests RPC handlers
• src/gateway/handlers/agent.ts - Metrics recording in agent.send: startRequest/endRequest, message/error counters, error events, tool failure events
• src/gateway/lane-queue.ts - totalPending() method for queue depth metric

Decisions Made

• MetricsCollector self-contained in GatewayServer constructor — no changes to services.ts needed
• Ring buffer sizes: 200 model calls, 500 events (configurable via constructor)
• Passed MetricsCollector instance directly to agent handler deps instead of individual callbacks — cleaner API
• startRequest called before laneQueue.enqueue to track full queuing + execution duration
• Tool failures recorded as separate error events with tool name context

Deviations from Plan

None - plan executed exactly as written.

Issues Encountered

None

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• All metrics RPC endpoints ready for Plan 02 (Dashboard UI) to consume
• system.metrics returns snapshot with counters, model call stats, queue depth
• system.events returns filtered/limited events (newest first)
• system.activeRequests returns in-flight request details
• GET /health available for external monitoring integration

Self-Check: PASSED

All 7 files verified present. Both task commits (bd1880a, a0feff9) verified in git log.

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Phase: 03-live-ops-dashboard Completed: 2026-02-10