diff --git a/.planning/phases/05-cable-test-integration/05-CONTEXT.md b/.planning/phases/05-cable-test-integration/05-CONTEXT.md
new file mode 100644
index 0000000..ddecc29
--- /dev/null
+++ b/.planning/phases/05-cable-test-integration/05-CONTEXT.md
@@ -0,0 +1,82 @@
+# Phase 5: Cable Test Integration - Context
+
+**Gathered:** 2026-04-10
+**Status:** Ready for planning
+**Mode:** Auto-generated (autonomous mode)
+
+<domain>
+## Phase Boundary
+
+Any cable can be tested, its results written to NetBox, and a label printed in a rapid test-verify-print workflow without leaving the Cable Test Station view. This phase delivers Treedix USB/DP/HDMI tester drivers, FNIRSI FNB58 power meter integration, cable test workflow UI, and auto-NetBox-record creation from test data.
+
+</domain>
+
+<decisions>
+## Implementation Decisions
+
+### Hardware Status
+- Treedix USB/DP/HDMI testers + FNIRSI FNB58 arrive 2026-04-13
+- Build code-complete with mock testers
+- Real protocol reverse-engineering deferred to operator
+- FNIRSI FNB58 has working community library: github.com/baryluk/fnirsi-usb-power-data-logger
+
+### Tester Driver Architecture
+- TesterDriver interface: Connect(), Read() (TestResult), Disconnect()
+- Per-tester implementations: TreedixUSBDriver, TreedixDPDriver, TreedixHDMIDriver, FNB58Driver
+- Auto-detect by VID/PID using existing USB Manager
+- TestResult struct holds all common fields (continuity, version, speed, etc.)
+
+### Cable Test Station UI
+- New /test route with three panels: tester readout, label preview, recent tests
+- Live SSE updates from tester
+- "Print & Next" button: creates NetBox cable record + prints label + clears for next
+- Mobile-friendly for bench use
+
+### NetBox Integration
+- Cable record created via netbox client (CreateCable method needed if absent)
+- test_data custom field stores structured JSON
+- catalog_status auto-set to "complete" after test
+
+### Backend Endpoints
+- POST /api/test/cable — receives test result, creates cable record in NetBox
+- GET /api/test/events — SSE for live tester data
+- GET /api/test/recent — last N test results
+
+</decisions>
+
+<code_context>
+## Existing Code Insights
+
+### Reusable Assets
+- internal/usb/manager.go — for tester USB device management
+- internal/printer/ — auto-print labels
+- internal/labels/cable.go — cable label renderer (Phase 4)
+- internal/netbox/client.go — needs CreateCable method
+- internal/netbox/types.go — Device type (cables are netbox cables, slightly different)
+
+### Integration Points
+- Add internal/tester/ package
+- Add internal/api/handlers/test.go
+- Add web/src/pages/CableTestPage.tsx
+- Wire route /test in router.tsx
+
+</code_context>
+
+<specifics>
+## Specific Ideas
+
+- TreedixUSBDriver mock returns deterministic test data for unit tests
+- FNB58Driver uses raw HID protocol (per baryluk reference)
+- Test result includes: cable_type, version, speed_gbps, max_power_w, pin_continuity, eMarker, resistance_ohm
+- Auto-print uses cable label template from Phase 4
+
+</specifics>
+
+<deferred>
+## Deferred Ideas
+
+- Real Treedix protocol implementation (hardware required)
+- Real FNIRSI FNB58 protocol (community lib reference, hardware required)
+- Network discovery / DUT identification
+
+</deferred>