Metrics Commands¶

Commands for viewing observability metrics including token usage, tool execution stats, and agent performance. Requires a running lango serve instance.

All metrics commands write table or JSON payloads through the Cobra command output stream so wrappers and test harnesses can capture them directly.

lango metrics [subcommand] [flags]

Persistent Flags¶

All metrics commands share these flags:

Flag	Type	Default	Description
`--output`	string	`table`	Output format: `table` or `json`
`--addr`	string	configured server address	Gateway address override

When --addr is omitted, metrics commands use the configured server.host and server.port, falling back to http://localhost:18789 only when those values are unavailable. Unknown --output values fail fast with an actionable error before any metrics command contacts the gateway.

lango metrics¶

Show a system metrics snapshot summary including uptime, total token usage, and tool execution count. The command writes table or JSON output through the Cobra command output stream so wrappers and test harnesses can capture it directly.

lango metrics [--output table|json] [--addr <url>]

Example:

$ lango metrics
=== System Metrics ===

Uptime:           2h15m30s
Total Input:      145200 tokens
Total Output:     52800 tokens
Tool Executions:  342

$ lango metrics --output json
{
  "uptime": "2h15m30s",
  "tokenUsage": {
    "inputTokens": 145200,
    "outputTokens": 52800
  },
  "toolExecutions": 342
}

lango metrics sessions¶

Show per-session token usage breakdown including input/output tokens and request count.

lango metrics sessions [--output table|json] [--addr <url>]

Example:

$ lango metrics sessions
SESSION                   INPUT   OUTPUT  TOTAL    REQUESTS
abc123def456ghij78901...  45200   12800   58000    24
xyz789abc012defg34567...  32000   9400    41400    18

$ lango metrics sessions --output json

lango metrics tools¶

Show per-tool execution statistics including call count, errors, error rate, and average duration.

lango metrics tools [--output table|json] [--addr <url>]

Example:

$ lango metrics tools
TOOL              COUNT  ERRORS  ERROR RATE  AVG DURATION
web_search        85     2       2.4%        1.2s
code_review       42     0       0.0%        3.5s
file_read         156    1       0.6%        0.1s
memory_store      63     0       0.0%        0.2s

lango metrics agents¶

Show per-agent token usage breakdown including input/output tokens and tool call count.

lango metrics agents [--output table|json] [--addr <url>]

Example:

$ lango metrics agents
AGENT       INPUT   OUTPUT  TOOL CALLS
operator    82000   31200   198
librarian   45200   15600   96
planner     18000   6000    48

lango metrics policy¶

Show policy decision statistics including block and observe counts with per-reason breakdowns. Fetches data from the /metrics/policy gateway endpoint and writes table or JSON output through the Cobra command output stream so wrappers and test harnesses can capture it directly.

lango metrics policy [--output table|json] [--addr <url>]

Example:

$ lango metrics policy
=== Policy Decisions ===

Blocks:    3
Observes:  12

--- By Reason ---
REASON                  COUNT
catastrophic_pattern    2
destructive_command     1
network_exfiltration    5
suspicious_pipe         7

$ lango metrics policy --output json
{
  "blocks": 3,
  "observes": 12,
  "byReason": {
    "catastrophic_pattern": 2,
    "destructive_command": 1,
    "network_exfiltration": 5,
    "suspicious_pipe": 7
  }
}

lango metrics history¶

Show historical token usage from the database for the specified number of days.

lango metrics history [--days <n>] [--output table|json] [--addr <url>]

Flag	Type	Default	Description
`--days`	int	`7`	Number of days to query

Example:

$ lango metrics history --days 3
Token usage history (last 3 days)
Records: 156 | Total Input: 520000 | Total Output: 185000

TIME              PROVIDER  MODEL               INPUT   OUTPUT
2026-03-07 14:30  openai    gpt-4o              4200    1800
2026-03-07 14:25  anthropic claude-sonnet-4-6... 3800    1200
2026-03-07 13:50  openai    gpt-4o              5100    2400

$ lango metrics history --days 7 --output json