---
phase: 03-container-actions
plan: 02
subsystem: telegram-callbacks
tags: [callback-query, inline-keyboard, telegram-api, n8n, http-request]

# Dependency graph
requires:
  - phase: 03-01
    provides: Basic container actions with match routing
provides:
  - Callback query handling for inline buttons
  - Did-you-mean suggestion flow for typos
  - 2-minute confirmation timeout
  - Message cleanup after button clicks
affects: [03-update-flow, 04-logs]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "HTTP Request node for Telegram inline keyboards (workaround for native node bug)"
    - "Callback data JSON encoding with short keys for 64-byte limit"
    - "Stateless confirmation via timestamp in callback_data"
    - "answerCallbackQuery + deleteMessage for UI cleanup"

key-files:
  created: []
  modified:
    - n8n-workflow.json

key-decisions:
  - "Use HTTP Request for sendMessage with inline_keyboard (native Telegram node doesn't support dynamic keyboards)"
  - "Encode action as single char (s/t/r/x) to fit in 64-byte callback_data limit"
  - "2-minute timeout enforced client-side via timestamp comparison"
  - "Delete suggestion message after any button click for clean UI"

patterns-established:
  - "Callback query routing: Route Update Type -> IF Callback Authenticated -> Parse Callback Data -> Route Callback"
  - "Score-based fuzzy matching for suggestions (score >= 2 required)"
  - "Three-branch callback handling: cancel, expired, execute"

# Metrics
duration: 15min
completed: 2026-01-30
---

# Phase 03 Plan 02: Callback Query Handling Summary

**Inline button infrastructure with did-you-mean suggestions using HTTP Request for Telegram API and stateless callback_data encoding**

## Performance

- **Duration:** 15 min
- **Started:** 2026-01-30T13:27:00Z
- **Completed:** 2026-01-30T13:42:00Z
- **Tasks:** 3
- **Files modified:** 1

## Accomplishments
- Telegram Trigger now receives both message and callback_query updates
- Route Update Type switch separates message vs callback flows
- IF Callback Authenticated validates user before processing callbacks
- Find Closest Match scores containers and suggests best match for typos
- Build Suggestion Keyboard creates inline_keyboard JSON with short callback_data
- Send Suggestion uses HTTP Request to Telegram API (workaround for native node limitation)
- Full callback flow: Parse -> Route -> Handle (Cancel/Expired/Execute)
- Cancel: answer query "Cancelled", delete suggestion message
- Expired: answer query with alert, delete message
- Execute: run Docker action, answer query, delete message, send result

## Task Commits

Each task was committed atomically:

1. **Task 1: Configure Telegram Trigger for callback queries** - `2cbf6e7` (feat)
2. **Task 2: Implement suggestion flow for no-match cases** - `56eea26` (feat)
3. **Task 3: Handle suggestion callback and execute action** - `768d758` (feat)

## Files Created/Modified
- `n8n-workflow.json` - Extended from 27 to 41 nodes with callback infrastructure:
  - Route Update Type, IF Callback Authenticated (Task 1)
  - Find Closest Match, Check Suggestion, Build Suggestion Keyboard, Send Suggestion (Task 2)
  - Parse Callback Data, Route Callback, Handle Cancel/Expired, Build/Execute/Parse Callback Action, Answer/Delete/Send result (Task 3)

## Decisions Made
- Use HTTP Request node for sendMessage with inline_keyboard - native Telegram node has expression bug with dynamic keyboards
- Encode action as single character (s=start, t=stop, r=restart, x=cancel) to fit callback_data 64-byte limit
- Require minimum score of 2 for suggestions - prevents suggesting unrelated containers
- 2-minute timeout enforced via timestamp in callback_data (stateless approach)
- Delete suggestion message after any button click for clean chat UI

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- Single-container suggestion flow complete
- Multiple-match batch confirmation still uses placeholder text (could be enhanced in future)
- Ready for Phase 04: Logs & Intelligence
- Container update flow (pull + recreate) deferred to later plan

---
*Phase: 03-container-actions*
*Completed: 2026-01-30*