Update Check — ONCE PER SESSION (mandatory) The first time this skill is used in a session, run the check-updates skill before proceeding.

• GitHub Copilot CLI / VS Code: invoke the check-updates skill.
• Claude Code / Cowork / Cursor / Windsurf / Codex: compare local vs remote package.json version.
• Skip if the check was already performed earlier in this session.

CRITICAL NOTES

1. To find the workspace details (including its ID) from workspace name: list all workspaces and, then, use JMESPath filtering
2. To find the item details (including its ID) from workspace ID, item type, and item name: list all items of that type in that workspace and, then, use JMESPath filtering

eventhouse-consumption-cli — Read-Only KQL Queries via CLI

Table of Contents

Task	Reference	Notes
Finding Workspaces and Items in Fabric	COMMON-CLI.md § Finding Workspaces and Items in Fabric	Mandatory — READ link first [needed for finding workspace id by its name or item id by its name, item type, and workspace id]
Fabric Topology & Key Concepts	COMMON-CORE.md § Fabric Topology & Key Concepts
Environment URLs	COMMON-CORE.md § Environment URLs	KQL Cluster URI is per-item
Authentication & Token Acquisition	COMMON-CORE.md § Authentication & Token Acquisition	Wrong audience = 401; read before any auth issue
Core Control-Plane REST APIs	COMMON-CORE.md § Core Control-Plane REST APIs
Pagination	COMMON-CORE.md § Pagination
Long-Running Operations (LRO)	COMMON-CORE.md § Long-Running Operations (LRO)
Rate Limiting & Throttling	COMMON-CORE.md § Rate Limiting & Throttling
OneLake Data Access	COMMON-CORE.md § OneLake Data Access	Requires storage.azure.com token, not Fabric token
Job Execution	COMMON-CORE.md § Job Execution
Capacity Management	COMMON-CORE.md § Capacity Management
Gotchas & Troubleshooting	COMMON-CORE.md § Gotchas & Troubleshooting
Best Practices	COMMON-CORE.md § Best Practices
Tool Selection Rationale	COMMON-CLI.md § Tool Selection Rationale
Authentication Recipes	COMMON-CLI.md § Authentication Recipes	az login flows and token acquisition
Fabric Control-Plane API via az rest	COMMON-CLI.md § Fabric Control-Plane API via az rest	Always pass --resource https://api.fabric.microsoft.com or az rest fails
Pagination Pattern	COMMON-CLI.md § Pagination Pattern
Long-Running Operations (LRO) Pattern	COMMON-CLI.md § Long-Running Operations (LRO) Pattern
OneLake Data Access via curl	COMMON-CLI.md § OneLake Data Access via curl	Use curl not az rest (different token audience)
Job Execution (CLI)	COMMON-CLI.md § Job Execution
OneLake Shortcuts	COMMON-CLI.md § OneLake Shortcuts
Capacity Management (CLI)	COMMON-CLI.md § Capacity Management
Composite Recipes	COMMON-CLI.md § Composite Recipes
Gotchas & Troubleshooting (CLI-Specific)	COMMON-CLI.md § Gotchas & Troubleshooting (CLI-Specific)	az rest audience, shell escaping, token expiry
Quick Reference: az rest Template	COMMON-CLI.md § Quick Reference: az rest Template
Quick Reference: Token Audience / CLI Tool Matrix	COMMON-CLI.md § Quick Reference: Token Audience ↔ CLI Tool Matrix	Which --resource + tool for each service
Connection Fundamentals	EVENTHOUSE-CONSUMPTION-CORE.md § Connection Fundamentals	Cluster URI discovery, az rest, REST API
Schema Discovery and Security	EVENTHOUSE-CONSUMPTION-CORE.md § Schema Discovery and Security	Schema Discovery, Security — workspace roles + KQL DB roles
Monitoring and Diagnostics	EVENTHOUSE-CONSUMPTION-CORE.md § Monitoring and Diagnostics
Performance Best Practices	EVENTHOUSE-CONSUMPTION-CORE.md § Performance Best Practices	Read before writing KQL — time filters, has vs contains
Common Consumption Patterns	EVENTHOUSE-CONSUMPTION-CORE.md § Common Consumption Patterns	Time-series, Top-N, percentile, dynamic fields
Gotchas, Troubleshooting, and Quick Reference	EVENTHOUSE-CONSUMPTION-CORE.md § Gotchas, Troubleshooting, and Quick Reference	Gotchas and Troubleshooting (12 issues), Quick Reference: Consumption Capabilities by Scenario
Table and Column Discovery	discovery-queries.md § Table and Column Discovery	Table Discovery, Column Statistics
Function and View Discovery	discovery-queries.md § Function and View Discovery	Function Discovery, Materialized View Discovery
Policy Discovery	discovery-queries.md § Policy Discovery
External Tables and Ingestion Mappings	discovery-queries.md § External Tables and Ingestion Mappings	External Table Discovery, Ingestion Mapping Discovery
Security Discovery	discovery-queries.md § Security Discovery
Database Overview Script	discovery-queries.md § Database Overview Script
Tool Stack	SKILL.md § Tool Stack
Connection	SKILL.md § Connection	eventhouse-specific az rest connection steps
Agentic Exploration ("Chat With My Data")	SKILL.md § Agentic Exploration	Start here for data exploration
Running Queries	SKILL.md § Running Queries	az rest, output formatting, export
Monitoring	SKILL.md § Monitoring
Must / Prefer / Avoid / Troubleshooting	SKILL.md § Must / Prefer / Avoid / Troubleshooting	MUST DO / AVOID / PREFER checklists
Examples	SKILL.md § Examples
Agent Integration Notes	SKILL.md § Agent Integration Notes

---

Tool Stack

Tool	Purpose	Install
az cli	KQL queries and management commands via Kusto REST API; Fabric control-plane discovery	winget install Microsoft.AzureCLI
jq	JSON processing and output formatting	winget install jqlang.jq

Connection

Step 1 — Discover KQL Database Query URI

# Get workspace ID (if not known)
WS_ID=$(az rest --method GET \
  --url "https://api.fabric.microsoft.com/v1/workspaces" \
  --resource "https://api.fabric.microsoft.com" \
  | jq -r '.value[] | select(.displayName=="MyWorkspace") | .id')

# List KQL Databases and get connection properties
az rest --method GET \
  --url "https://api.fabric.microsoft.com/v1/workspaces/${WS_ID}/kqlDatabases" \
  --resource "https://api.fabric.microsoft.com" \
  | jq '.value[] | {name: .displayName, id: .id, queryUri: .properties.queryServiceUri, dbName: .properties.databaseName}'

Step 2 — Set Connection Variables

CLUSTER_URI="https://<cluster>.kusto.fabric.microsoft.com"
DB_NAME="MyKqlDatabase"

Step 3 — Verify Connection

Important — body file pattern: KQL queries contain | (pipe) characters which break shell escaping in both bash and PowerShell. Always write the JSON body to a temp file and reference it with --body @<file>. This is the recommended approach for all az rest KQL calls. On PowerShell, use @{db="X";csl="..."} | ConvertTo-Json -Compress | Out-File $env:TEMP\kql_body.json -Encoding utf8NoBOM then --body "@$env:TEMP\kql_body.json".

# Write body to temp file (avoids pipe escaping issues)
cat > /tmp/kql_body.json << 'EOF'
{"db":"MyKqlDatabase","csl":"print Message = 'Connected successfully', Cluster = current_cluster_endpoint(), Timestamp = now()"}
EOF

az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0].Rows'

---

Agentic Exploration

"Chat With My Data" — Discovery Sequence

When the user asks to explore or query an Eventhouse without specifying tables:

Step 1 → .show tables                                    // discover tables
Step 2 → .show table <TABLE> schema as json              // understand columns + types
Step 3 → <TABLE> | take 10                               // see sample data
Step 4 → <TABLE> | summarize count() by bin(Timestamp, 1h) | render timechart  // shape of data
Step 5 → Formulate targeted query based on user's question

Schema-Aware Query Generation

After schema discovery, generate queries using actual column names and types:

// Example: user asks "show me errors in the last hour"
// After discovering table "AppEvents" with columns: Timestamp, Level, Message, Source
AppEvents
| where Timestamp > ago(1h)
| where Level == "Error"
| summarize ErrorCount = count() by Source, bin(Timestamp, 5m)
| order by ErrorCount desc

---

Running Queries

Via az rest

Always use the temp-file pattern for --body — KQL pipes (|) break inline shell escaping.

# Run a KQL query
cat > /tmp/kql_body.json << 'EOF'
{"db":"MyDB","csl":"Events | where Timestamp > ago(1h) | count"}
EOF

az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0].Rows'

Output Formatting

# Pretty-print results as a table with jq
cat > /tmp/kql_body.json << 'EOF'
{"db":"MyDB","csl":".show tables"}
EOF

az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0] | [.Columns[].ColumnName] as $cols | .Rows[] | [$cols, .] | transpose | map({(.[0]): .[1]}) | add'

# Save results to file
cat > /tmp/kql_body.json << 'EOF'
{"db":"MyDB","csl":"Events | where Timestamp > ago(1h) | summarize count() by EventType"}
EOF

az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  --output-file results.json

---

Monitoring

// Active queries
.show queries

// Recent commands (last hour)
.show commands
| where StartedOn > ago(1h)
| project StartedOn, CommandType, Text = substring(Text, 0, 80), Duration, State
| order by StartedOn desc

// Ingestion failures (for context when data seems stale)
.show ingestion failures
| where FailedOn > ago(24h)
| summarize count() by ErrorCode
| top 5 by count_

---

Must / Prefer / Avoid / Troubleshooting

Must

• Always include time filters — where Timestamp > ago(...) must be present on time-series tables.
• Discover schema before querying — run .show tables and .show table T schema as json first.
• Use has for term search — indexed and fast; only fall back to contains for substring needs.
• Verify cluster URI — KQL Database URIs are per-item; always resolve via Fabric REST API.

Prefer

• az rest for CLI query sessions; Fabric KQL MCP server for agent-integrated workflows.
• project early to drop unneeded columns before aggregation.
• materialize() when a sub-expression is used multiple times.
• take 100 for initial exploration; avoid full table scans.
• render timechart for time-series; render piechart for distribution.

Avoid

• contains on large tables — full scan, not indexed. Use has or has_cs.
• join without filtering both sides first — causes memory explosion.
• SELECT * equivalent (project all columns) on wide tables.
• Missing bin() in time-series summarize — produces one row per unique timestamp.
• Hardcoded cluster URIs — always resolve from Fabric REST API or environment variables.

Troubleshooting

Symptom	Fix
az rest auth fails	Run az login first; ensure --resource "https://kusto.kusto.windows.net" is set
Empty results on valid table	Check database context; may need database("name").table
Query timeout	Add tighter time filter; check .show queries for competing queries
Forbidden (403)	Request viewer role on the KQL Database
Results truncated	Default limit is 500K rows; add set truncationmaxrecords = N; before query
KQL pipe | breaks PowerShell or bash	Never inline KQL in --body. Write JSON to a temp file and use --body @file.json (see Running Queries)

---

Examples

Example 1: Discover and Query

# 1. Set connection variables (after discovering URI via Step 1)
CLUSTER_URI="https://<your-cluster>.kusto.fabric.microsoft.com"
DB_NAME="SalesDB"

# 2. Discover tables
cat > /tmp/kql_body.json << EOF
{"db":"${DB_NAME}","csl":".show tables"}
EOF
az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0].Rows'

# 3. Explore schema
cat > /tmp/kql_body.json << EOF
{"db":"${DB_NAME}","csl":".show table Orders schema as json"}
EOF
az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0].Rows'

# 4. Sample data
cat > /tmp/kql_body.json << EOF
{"db":"${DB_NAME}","csl":"Orders | take 10"}
EOF
az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  | jq '.Tables[0].Rows'

// 5. Analytical query (via az rest --body @file)
Orders
| where OrderDate > ago(30d)
| summarize
    TotalOrders = count(),
    TotalRevenue = sum(Amount)
    by bin(OrderDate, 1d)
| render timechart

Example 2: Cross-Database Query

// Query across KQL databases in the same Eventhouse
let orders = database("SalesDB").Orders | where OrderDate > ago(7d);
let products = database("CatalogDB").Products;
orders
| join kind=inner (products) on ProductId
| summarize Revenue = sum(Amount) by ProductName
| top 10 by Revenue desc

Example 3: Export Results to File

# Run query and save results to JSON
cat > /tmp/kql_body.json << 'EOF'
{"db":"MyDB","csl":"Events | where Timestamp > ago(1d) | summarize count() by EventType"}
EOF

az rest --method POST \
  --url "${CLUSTER_URI}/v1/rest/query" \
  --resource "https://kusto.kusto.windows.net" \
  --headers "Content-Type=application/json" \
  --body @/tmp/kql_body.json \
  --output-file results.json

# Convert to CSV with jq
cat results.json \
  | jq -r '.Tables[0] | (.Columns | map(.ColumnName)), (.Rows[]) | @csv' > results.csv

---

Agent Integration Notes

• This skill is read-only — it does not create, alter, or drop database objects.
• For authoring operations (table management, ingestion, policies), delegate to eventhouse-authoring-cli.
• For cross-workload orchestration (Spark + SQL + KQL), delegate to the FabricDataEngineer agent.
• The Fabric KQL MCP server (fabric-kql in mcp-setup/mcp-config-template.json) can be used as an alternative to az rest for agent-integrated query execution.