diff --git a/.claude/commands/mgw/board.md b/.claude/commands/mgw/board.md
index 4131869..e1b0c98 100644
--- a/.claude/commands/mgw/board.md
+++ b/.claude/commands/mgw/board.md
@@ -1,7 +1,7 @@
 ---
 name: mgw:board
-description: Create, show, and configure the GitHub Projects v2 board for this repo
-argument-hint: "<create|show|configure|views>"
+description: Create, show, configure, and sync the GitHub Projects v2 board for this repo
+argument-hint: "<create|show|configure|views|sync>"
 allowed-tools:
   - Bash
   - Read
@@ -10,7 +10,7 @@ allowed-tools:
 ---
 
 <objective>
-Manage the GitHub Projects v2 board for the current MGW project. Four subcommands:
+Manage the GitHub Projects v2 board for the current MGW project. Five subcommands:
 
 - `create` — Idempotent: creates the board and custom fields if not yet in project.json.
   If board already exists in project.json, exits cleanly with the board URL.
@@ -21,6 +21,11 @@ Manage the GitHub Projects v2 board for the current MGW project. Four subcommand
 - `views` — Creates GitHub Projects v2 layout views (Board/Kanban, Table, Roadmap).
   Subcommands: `views kanban`, `views table`, `views roadmap`. Creates the view and
   outputs instructions for manual group-by configuration in the GitHub UI.
+- `sync` — Reconciles all board items with current `.mgw/active/` state. Iterates every
+  active state file, looks up the corresponding board item by issue number, adds missing
+  items, and updates Status, AI Agent State, Phase, and Milestone fields to match local
+  state. Designed for use after context resets or board drift. Prints a reconciliation
+  diff table.
 
 All board API calls use GitHub GraphQL v4. Board metadata is stored in project.json
 under `project.project_board.fields`. Board item sync (adding issues as board items)
@@ -52,20 +57,21 @@ Board schema: .mgw/board-schema.json (if exists) or embedded defaults from docs/
 SUBCOMMAND=$(echo "$ARGUMENTS" | awk '{print $1}')
 
 if [ -z "$SUBCOMMAND" ]; then
-  echo "Usage: /mgw:board <create|show|configure|views>"
+  echo "Usage: /mgw:board <create|show|configure|views|sync>"
   echo ""
   echo "  create          Create board and custom fields (idempotent)"
   echo "  show            Display board state and item counts"
   echo "  configure       Update board field options"
   echo "  views <layout>  Create layout views (kanban, table, roadmap)"
+  echo "  sync            Reconcile all board items with current .mgw/ state"
   exit 1
 fi
 
 case "$SUBCOMMAND" in
-  create|show|configure|views) ;;
+  create|show|configure|views|sync) ;;
   *)
     echo "Unknown subcommand: ${SUBCOMMAND}"
-    echo "Valid: create, show, configure, views"
+    echo "Valid: create, show, configure, views, sync"
     exit 1
     ;;
 esac
@@ -1200,6 +1206,419 @@ fi  # end views subcommand
 ```
 </step>
 
+<step name="subcommand_sync">
+**Execute 'sync' subcommand:**
+
+Only run if `$SUBCOMMAND = "sync"`.
+
+Reconcile all `.mgw/active/*.json` state files with their GitHub Projects v2 board items.
+Adds missing issues to the board, then updates Status, AI Agent State, Phase, and
+Milestone fields to match current local state. Prints a reconciliation diff table.
+
+```bash
+if [ "$SUBCOMMAND" = "sync" ]; then
+  if [ "$BOARD_CONFIGURED" = "false" ]; then
+    echo "No board configured. Run /mgw:board create first."
+    exit 1
+  fi
+
+  echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+  echo " MGW ► BOARD SYNC: ${PROJECT_NAME}"
+  echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+  echo ""
+```
+
+**Collect active state files:**
+
+```bash
+  ACTIVE_DIR="${MGW_DIR}/active"
+
+  if ! ls "${ACTIVE_DIR}"/*.json 1>/dev/null 2>&1; then
+    echo "No active issues found in ${ACTIVE_DIR}/"
+    echo "Nothing to sync."
+    exit 0
+  fi
+
+  ACTIVE_FILES=$(ls "${ACTIVE_DIR}"/*.json 2>/dev/null)
+  ACTIVE_COUNT=$(echo "$ACTIVE_FILES" | wc -l)
+
+  echo "Reconciling ${ACTIVE_COUNT} active issues against board..."
+  echo ""
+```
+
+**Read field IDs from project.json:**
+
+```bash
+  STATUS_FIELD_ID=$(echo "$FIELDS_JSON" | python3 -c "
+import json,sys
+fields = json.load(sys.stdin)
+print(fields.get('status', {}).get('field_id', ''))
+" 2>/dev/null)
+
+  AI_STATE_FIELD_ID=$(echo "$FIELDS_JSON" | python3 -c "
+import json,sys
+fields = json.load(sys.stdin)
+print(fields.get('ai_agent_state', {}).get('field_id', ''))
+" 2>/dev/null)
+
+  PHASE_FIELD_ID=$(echo "$FIELDS_JSON" | python3 -c "
+import json,sys
+fields = json.load(sys.stdin)
+print(fields.get('phase', {}).get('field_id', ''))
+" 2>/dev/null)
+
+  MILESTONE_FIELD_ID=$(echo "$FIELDS_JSON" | python3 -c "
+import json,sys
+fields = json.load(sys.stdin)
+print(fields.get('milestone', {}).get('field_id', ''))
+" 2>/dev/null)
+
+  STATUS_OPTIONS=$(echo "$FIELDS_JSON" | python3 -c "
+import json,sys
+fields = json.load(sys.stdin)
+print(json.dumps(fields.get('status', {}).get('options', {})))
+" 2>/dev/null || echo "{}")
+```
+
+**Fetch all current board items in a single GraphQL call:**
+
+```bash
+  echo "Fetching current board items from GitHub..."
+
+  BOARD_ITEMS_RESULT=$(gh api graphql -f query='
+    query($projectId: ID!) {
+      node(id: $projectId) {
+        ... on ProjectV2 {
+          items(first: 100) {
+            nodes {
+              id
+              content {
+                ... on Issue {
+                  number
+                  id
+                }
+                ... on PullRequest {
+                  number
+                  id
+                }
+              }
+              fieldValues(first: 10) {
+                nodes {
+                  ... on ProjectV2ItemFieldSingleSelectValue {
+                    name
+                    field { ... on ProjectV2SingleSelectField { name } }
+                  }
+                  ... on ProjectV2ItemFieldTextValue {
+                    text
+                    field { ... on ProjectV2Field { name } }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  ' -f projectId="$BOARD_NODE_ID" 2>/dev/null)
+
+  # Build: issue_number → {item_id, current_status, current_ai_state, current_phase, current_milestone}
+  BOARD_ITEM_MAP=$(echo "$BOARD_ITEMS_RESULT" | python3 -c "
+import json,sys
+d = json.load(sys.stdin)
+nodes = d.get('data', {}).get('node', {}).get('items', {}).get('nodes', [])
+result = {}
+for node in nodes:
+    content = node.get('content', {})
+    if not content:
+        continue
+    num = content.get('number')
+    if num is None:
+        continue
+    item_id = node.get('id', '')
+    status = ''
+    ai_state = ''
+    phase = ''
+    milestone = ''
+    for fv in node.get('fieldValues', {}).get('nodes', []):
+        fname = fv.get('field', {}).get('name', '')
+        if fname == 'Status':
+            status = fv.get('name', '')
+        elif fname == 'AI Agent State':
+            ai_state = fv.get('text', '')
+        elif fname == 'Phase':
+            phase = fv.get('text', '')
+        elif fname == 'Milestone':
+            milestone = fv.get('text', '')
+    result[str(num)] = {
+        'item_id': item_id,
+        'status': status,
+        'ai_agent_state': ai_state,
+        'phase': phase,
+        'milestone': milestone
+    }
+print(json.dumps(result))
+" 2>/dev/null || echo "{}")
+
+  if [ "$BOARD_ITEM_MAP" = "{}" ] && [ -n "$BOARD_ITEMS_RESULT" ]; then
+    echo "WARNING: Could not parse board items. Continuing with empty map."
+  fi
+```
+
+**Reconcile each active state file:**
+
+```bash
+  SYNC_RESULTS=()
+  UPDATED_COUNT=0
+  ADDED_COUNT=0
+  ERROR_COUNT=0
+
+  for STATE_FILE in $ACTIVE_FILES; do
+    # Parse state file
+    ISSUE_DATA=$(python3 -c "
+import json,sys
+try:
+    s = json.load(open('${STATE_FILE}'))
+    num = str(s.get('issue', {}).get('number', ''))
+    title = s.get('issue', {}).get('title', 'Unknown')[:45]
+    stage = s.get('pipeline_stage', 'new')
+    route = s.get('gsd_route', '') or ''
+    labels = s.get('issue', {}).get('labels', [])
+    # Extract phase from labels matching 'phase:*'
+    phase_val = ''
+    for lbl in labels:
+        if isinstance(lbl, str) and lbl.startswith('phase:'):
+            phase_val = lbl.replace('phase:', '')
+            break
+        elif isinstance(lbl, dict) and lbl.get('name', '').startswith('phase:'):
+            phase_val = lbl['name'].replace('phase:', '')
+            break
+    print(json.dumps({'number': num, 'title': title, 'stage': stage, 'route': route, 'phase': phase_val}))
+except Exception as e:
+    print(json.dumps({'error': str(e)}))
+" 2>/dev/null || echo '{"error":"parse failed"}')
+
+    ISSUE_NUMBER=$(echo "$ISSUE_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('number',''))" 2>/dev/null)
+    ISSUE_TITLE=$(echo "$ISSUE_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('title','Unknown'))" 2>/dev/null)
+    PIPELINE_STAGE=$(echo "$ISSUE_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('stage','new'))" 2>/dev/null)
+    PHASE_VALUE=$(echo "$ISSUE_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('phase',''))" 2>/dev/null)
+
+    if [ -z "$ISSUE_NUMBER" ]; then
+      SYNC_RESULTS+=("| ? | (parse error: ${STATE_FILE##*/}) | — | ERROR: could not read state |")
+      ERROR_COUNT=$((ERROR_COUNT + 1))
+      continue
+    fi
+
+    # Look up board item
+    ITEM_DATA=$(echo "$BOARD_ITEM_MAP" | python3 -c "
+import json,sys
+m = json.load(sys.stdin)
+d = m.get('${ISSUE_NUMBER}', {})
+print(json.dumps(d))
+" 2>/dev/null || echo "{}")
+
+    BOARD_ITEM_ID=$(echo "$ITEM_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('item_id',''))" 2>/dev/null)
+    CURRENT_STATUS=$(echo "$ITEM_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('status',''))" 2>/dev/null)
+    CURRENT_PHASE=$(echo "$ITEM_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('phase',''))" 2>/dev/null)
+    CURRENT_MILESTONE=$(echo "$ITEM_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('milestone',''))" 2>/dev/null)
+
+    CHANGED_FIELDS=""
+
+    # If issue is not on board, add it
+    if [ -z "$BOARD_ITEM_ID" ]; then
+      ISSUE_NODE_ID=$(gh issue view "$ISSUE_NUMBER" --json id -q .id 2>/dev/null || echo "")
+      if [ -n "$ISSUE_NODE_ID" ]; then
+        ADD_RESULT=$(gh api graphql -f query='
+          mutation($projectId: ID!, $contentId: ID!) {
+            addProjectV2ItemById(input: {projectId: $projectId, contentId: $contentId}) {
+              item { id }
+            }
+          }
+        ' -f projectId="$BOARD_NODE_ID" -f contentId="$ISSUE_NODE_ID" \
+          --jq '.data.addProjectV2ItemById.item.id' 2>/dev/null || echo "")
+
+        if [ -n "$ADD_RESULT" ]; then
+          BOARD_ITEM_ID="$ADD_RESULT"
+          CHANGED_FIELDS="added to board"
+          ADDED_COUNT=$((ADDED_COUNT + 1))
+        else
+          SYNC_RESULTS+=("| #${ISSUE_NUMBER} | ${ISSUE_TITLE} | ${PIPELINE_STAGE} | ERROR: could not add to board |")
+          ERROR_COUNT=$((ERROR_COUNT + 1))
+          continue
+        fi
+      else
+        SYNC_RESULTS+=("| #${ISSUE_NUMBER} | ${ISSUE_TITLE} | ${PIPELINE_STAGE} | ERROR: could not resolve issue node ID |")
+        ERROR_COUNT=$((ERROR_COUNT + 1))
+        continue
+      fi
+    fi
+
+    # Get milestone title from project.json for this issue's milestone
+    MILESTONE_VALUE=$(python3 -c "
+import json,sys
+try:
+    p = json.load(open('${MGW_DIR}/project.json'))
+    current_ms = p.get('current_milestone', 1)
+    for i, m in enumerate(p.get('milestones', []), 1):
+        for issue in m.get('issues', []):
+            if str(issue.get('github_number', '')) == '${ISSUE_NUMBER}':
+                print(m.get('title', ''))
+                sys.exit(0)
+    print('')
+except:
+    print('')
+" 2>/dev/null)
+
+    # Update Status field if it differs
+    if [ -n "$STATUS_FIELD_ID" ]; then
+      DESIRED_OPTION_ID=$(echo "$STATUS_OPTIONS" | python3 -c "
+import json,sys
+opts = json.load(sys.stdin)
+print(opts.get('${PIPELINE_STAGE}', ''))
+" 2>/dev/null)
+
+      if [ -n "$DESIRED_OPTION_ID" ]; then
+        # Map current board status name back to stage for comparison
+        CURRENT_STAGE=$(echo "$CURRENT_STATUS" | python3 -c "
+import sys
+stage_map = {
+    'New': 'new', 'Triaged': 'triaged', 'Needs Info': 'needs-info',
+    'Needs Security Review': 'needs-security-review', 'Discussing': 'discussing',
+    'Approved': 'approved', 'Planning': 'planning', 'Executing': 'executing',
+    'Verifying': 'verifying', 'PR Created': 'pr-created', 'Done': 'done',
+    'Failed': 'failed', 'Blocked': 'blocked'
+}
+label = sys.stdin.read().strip()
+print(stage_map.get(label, ''))
+" 2>/dev/null)
+
+        if [ "$CURRENT_STAGE" != "$PIPELINE_STAGE" ]; then
+          gh api graphql -f query='
+            mutation($projectId: ID!, $itemId: ID!, $fieldId: ID!, $optionId: String!) {
+              updateProjectV2ItemFieldValue(input: {
+                projectId: $projectId
+                itemId: $itemId
+                fieldId: $fieldId
+                value: { singleSelectOptionId: $optionId }
+              }) { projectV2Item { id } }
+            }
+          ' -f projectId="$BOARD_NODE_ID" \
+            -f itemId="$BOARD_ITEM_ID" \
+            -f fieldId="$STATUS_FIELD_ID" \
+            -f optionId="$DESIRED_OPTION_ID" 2>/dev/null || true
+
+          if [ -n "$CHANGED_FIELDS" ]; then
+            CHANGED_FIELDS="${CHANGED_FIELDS}, Status (${CURRENT_STATUS:-none}→${PIPELINE_STAGE})"
+          else
+            CHANGED_FIELDS="Status (${CURRENT_STATUS:-none}→${PIPELINE_STAGE})"
+          fi
+          UPDATED_COUNT=$((UPDATED_COUNT + 1))
+        fi
+      fi
+    fi
+
+    # Update AI Agent State field — sync always clears it (ephemeral during execution)
+    if [ -n "$AI_STATE_FIELD_ID" ] && [ -n "$CURRENT_AI_STATE" ] && [ "$CURRENT_AI_STATE" != "" ]; then
+      CURRENT_AI_STATE=$(echo "$ITEM_DATA" | python3 -c "import json,sys; print(json.load(sys.stdin).get('ai_agent_state',''))" 2>/dev/null)
+      if [ -n "$CURRENT_AI_STATE" ]; then
+        gh api graphql -f query='
+          mutation($projectId: ID!, $itemId: ID!, $fieldId: ID!, $text: String!) {
+            updateProjectV2ItemFieldValue(input: {
+              projectId: $projectId
+              itemId: $itemId
+              fieldId: $fieldId
+              value: { text: $text }
+            }) { projectV2Item { id } }
+          }
+        ' -f projectId="$BOARD_NODE_ID" \
+          -f itemId="$BOARD_ITEM_ID" \
+          -f fieldId="$AI_STATE_FIELD_ID" \
+          -f text="" 2>/dev/null || true
+
+        if [ -n "$CHANGED_FIELDS" ]; then
+          CHANGED_FIELDS="${CHANGED_FIELDS}, AI Agent State (cleared)"
+        else
+          CHANGED_FIELDS="AI Agent State (cleared)"
+        fi
+      fi
+    fi
+
+    # Update Phase field if it differs
+    if [ -n "$PHASE_FIELD_ID" ] && [ -n "$PHASE_VALUE" ] && [ "$PHASE_VALUE" != "$CURRENT_PHASE" ]; then
+      gh api graphql -f query='
+        mutation($projectId: ID!, $itemId: ID!, $fieldId: ID!, $text: String!) {
+          updateProjectV2ItemFieldValue(input: {
+            projectId: $projectId
+            itemId: $itemId
+            fieldId: $fieldId
+            value: { text: $text }
+          }) { projectV2Item { id } }
+        }
+      ' -f projectId="$BOARD_NODE_ID" \
+        -f itemId="$BOARD_ITEM_ID" \
+        -f fieldId="$PHASE_FIELD_ID" \
+        -f text="$PHASE_VALUE" 2>/dev/null || true
+
+      if [ -n "$CHANGED_FIELDS" ]; then
+        CHANGED_FIELDS="${CHANGED_FIELDS}, Phase (${CURRENT_PHASE:-none}→${PHASE_VALUE})"
+      else
+        CHANGED_FIELDS="Phase (${CURRENT_PHASE:-none}→${PHASE_VALUE})"
+      fi
+    fi
+
+    # Update Milestone field if it differs
+    if [ -n "$MILESTONE_FIELD_ID" ] && [ -n "$MILESTONE_VALUE" ] && [ "$MILESTONE_VALUE" != "$CURRENT_MILESTONE" ]; then
+      gh api graphql -f query='
+        mutation($projectId: ID!, $itemId: ID!, $fieldId: ID!, $text: String!) {
+          updateProjectV2ItemFieldValue(input: {
+            projectId: $projectId
+            itemId: $itemId
+            fieldId: $fieldId
+            value: { text: $text }
+          }) { projectV2Item { id } }
+        }
+      ' -f projectId="$BOARD_NODE_ID" \
+        -f itemId="$BOARD_ITEM_ID" \
+        -f fieldId="$MILESTONE_FIELD_ID" \
+        -f text="$MILESTONE_VALUE" 2>/dev/null || true
+
+      if [ -n "$CHANGED_FIELDS" ]; then
+        CHANGED_FIELDS="${CHANGED_FIELDS}, Milestone (${CURRENT_MILESTONE:-none}→${MILESTONE_VALUE})"
+      else
+        CHANGED_FIELDS="Milestone (${CURRENT_MILESTONE:-none}→${MILESTONE_VALUE})"
+      fi
+    fi
+
+    if [ -z "$CHANGED_FIELDS" ]; then
+      CHANGED_FIELDS="no changes"
+    fi
+
+    SYNC_RESULTS+=("| #${ISSUE_NUMBER} | ${ISSUE_TITLE} | ${PIPELINE_STAGE} | ${CHANGED_FIELDS} |")
+  done
+```
+
+**Print reconciliation diff table:**
+
+```bash
+  echo "| Issue | Title | Stage | Changes |"
+  echo "|-------|-------|-------|---------|"
+  for ROW in "${SYNC_RESULTS[@]}"; do
+    echo "$ROW"
+  done
+
+  echo ""
+  echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+  echo " Sync complete: ${ACTIVE_COUNT} checked, ${UPDATED_COUNT} updated, ${ADDED_COUNT} added, ${ERROR_COUNT} errors"
+  echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+  if [ "$ERROR_COUNT" -gt 0 ]; then
+    echo ""
+    echo "WARNING: ${ERROR_COUNT} issue(s) had errors. Check board manually: ${BOARD_URL}"
+  fi
+
+fi  # end sync subcommand
+```
+</step>
+
 </process>
 
 <success_criteria>
@@ -1242,4 +1661,19 @@ fi  # end views subcommand
 - [ ] views roadmap: explains date field limitation — MGW uses iteration-based tracking without explicit dates
 - [ ] views roadmap: documents milestone due date workaround via gh api PATCH
 - [ ] views: references docs/BOARD-SCHEMA.md for full view configuration documentation
+- [ ] sync: board not configured → clear error message directing to /mgw:board create
+- [ ] sync: no active state files → "Nothing to sync" message, clean exit
+- [ ] sync: fetches all board items in a single GraphQL query (node-based, by BOARD_NODE_ID)
+- [ ] sync: builds issue_number → {item_id, current field values} map from GraphQL result
+- [ ] sync: for each active state file, parses issue.number, pipeline_stage, labels (for Phase)
+- [ ] sync: issues not yet on board are added via addProjectV2ItemById mutation
+- [ ] sync: Status field updated when pipeline_stage differs from current board Status value
+- [ ] sync: AI Agent State field cleared (set to empty) when it has a stale value
+- [ ] sync: Phase field updated when phase label value differs from current board Phase value
+- [ ] sync: Milestone field updated when project.json milestone title differs from board value
+- [ ] sync: only differing fields are updated (no-op for fields already matching)
+- [ ] sync: per-item errors are logged in diff table rows as ERROR entries, reconciliation continues
+- [ ] sync: prints reconciliation diff table with columns: Issue, Title, Stage, Changes
+- [ ] sync: prints summary line: "N checked, M updated, K added, 0 errors"
+- [ ] sync: if any errors occurred, prints warning with board URL for manual inspection
 </success_criteria>
diff --git a/.claude/commands/mgw/workflows/board-sync.md b/.claude/commands/mgw/workflows/board-sync.md
index a35e692..3f406f4 100644
--- a/.claude/commands/mgw/workflows/board-sync.md
+++ b/.claude/commands/mgw/workflows/board-sync.md
@@ -401,3 +401,4 @@ fi
 | run.md | sync_pr_to_board | After PR creation (before cross-ref is recorded) |
 | pr.md | sync_pr_to_board | After PR creation in create_pr step (linked mode only) |
 | sync.md | sync_pr_to_board | Board reconciliation — for each PR link in cross-refs |
+| board.md (sync) | bulk reconciliation | Iterates all .mgw/active/*.json, fetches board items via node ID query, applies updateProjectV2ItemFieldValue for Status/AI Agent State/Phase/Milestone fields. Uses same GraphQL mutations as the three utility functions above, but in a single bulk loop with diff tracking. |