analyze-logs

Analyze structured NDJSON wide-event logs from evlog file system drains.

Updated Sep 16, 2026
One-click install
npx skills add https://github.com/jasonviipers/vipers --skill analyze-logs-jasonviipers
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: analyze-logs
Source: https://github.com/jasonviipers/vipers/tree/main/.agents/skills/analyze-logs
Command: npx skills add https://github.com/jasonviipers/vipers --skill analyze-logs-jasonviipers

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Debugging application errors and investigating slow requests often requires digging through unstructured logs. This Skill reads structured wide-event logs written by evlog's file system drain and turns them into actionable answers about errors, performance, and request behavior. ## Core Features & Use Cases - Error Investigation: Filter events by level or status code, then read error.message, error.data.why, and error.data.fix to explain failures and suggest remediation. - Performance Analysis: Filter and sort on durationMs to find slow endpoints, degrading performance, and time-of-day patterns. - Request Tracing & Patterns: Trace a single request by requestId, compute error rates per endpoint, and compare client-side versus server-side errors. - Use Case: A user reports intermittent 500 errors on the checkout endpoint. The Skill reads the latest .jsonl log file, filters error events for /api/checkout, groups them by error.message, and surfaces the root cause with the suggested fix. ## Quick Start Analyze the logs in .evlog/logs and tell me why the recent requests to /api/checkout are failing.

Frequently Asked Questions about analyze-logs

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I analyze application logs to debug errors?▼

Read the most recent .jsonl file in .evlog/logs/, parse each line as a JSON event, and filter for level "error" or status >= 400. Each event contains error.message, error.data.why, and error.data.fix fields that explain the failure and suggest remediation.

How to find slow requests in evlog log files?▼

Filter events where durationMs exceeds your threshold (e.g. 1000) and sort descending. Group by path to identify slow endpoints and check timestamps for time-of-day patterns.

What log format does evlog write to .evlog/logs?▼

Evlog writes one self-contained JSON wide event per line in NDJSON mode, or multi-line indented JSON in pretty mode. Files are named by date, like 2026-03-14.jsonl, and each event includes timestamp, level, method, path, status, durationMs, and requestId.

Why is the .evlog/logs directory empty or missing?▼

The file system drain is not enabled. Run npx @evlog/cli init --yes --drain fs to wire it automatically, or manually pass createFsDrain() from evlog/fs to your framework's evlog integration, then generate traffic to produce logs.

Can I trace a single request across the logs?▼

Yes. Filter events by the requestId field to retrieve the complete wide event for that request. Unlike traditional logs, one line contains all context for the request, so no multi-line correlation is needed.