Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/muratmirgun/gophersnpx agentmods add skills/muratmirgun/gophers/go-loggingWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/muratmirgun/gophers/go-logging)<a href="https://agentmods.dev/skills/muratmirgun/gophers/go-logging"><img src="https://agentmods.dev/badge/skills/muratmirgun/gophers/go-logging/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/muratmirgun/gophers/go-logging"><img src="https://agentmods.dev/badge/skills/muratmirgun/gophers/go-logging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00083 | $0.02205 |
| Opus 5.5 | $0.00033 | $0.00882 |
| Sonnet 5.5 | $0.00017 | $0.00441 |
| Haiku 4.5 | $0.00008 | $0.00220 |
Grade A, and why
go-logging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Go Logging
Logs are written for operators — the human who will be paged at 3 a.m. and needs to know what happened. Every log line either helps diagnose a production issue or it is noise. log/slog from the standard library is the default; reach for anything else only after measuring.
This skill covers logging only. Metrics, distributed tracing, profiling, and RUM are a separate concern — they belong to a future
go-observabilityskill. Do not confuse them with logging here.
Core Rules
- Use
log/slogfor new code. Structured, leveled, in the standard library since Go 1.21. - Static message, structured fields. The message describes what happened; data goes in key-value attributes.
- Log or return, never both. Logging a wrapped error makes the same failure appear at every layer.
- Log at the boundary. HTTP handlers, job runners, and
mainlog. Library code wraps and returns. - Use snake_case keys consistently across the codebase (
user_id,request_id,elapsed_ms). slog.Erroralways carries an"err"attribute. Without it, you logged a sentence, not an error.- Never log secrets, PII, or unbounded data. Tokens, full credit cards, request bodies — none of it.
Choosing a Logger
| Situation | Use |
|---|---|
| New production service | log/slog |
| Trivial CLI / one-off script | log (the standard package) |
| Measured hot-path bottleneck where slog dominates the flame graph | zap or zerolog, but keep the structured style |
| Existing zap/logrus/zerolog code | Migrate to slog with a bridge handler; see references/slog-handler-ecosystem.md |
slog's API is stable, the ecosystem has consolidated around it, and JSON output works with every log shipper. Do not introduce a third-party logger without a benchmark showing the win.
Structured Logging
Build log messages from a static message plus typed fields:
// Good — static message, structured fields
slog.Info("order placed", "order_id", orderID, "total_cents", totalCents)
// Bad — dynamic data baked into the message string
slog.Info(fmt.Sprintf("order %d placed for $%.2f", orderID, total))
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 195 lines · 83 tokens per session scan A 3645a4b653d3
go-logging is a skill published in the GitHub repository muratmirgun/gophers (9 stars, last pushed 2mo ago), licensed MIT. It adds 83 tokens to every session and 2,205 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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