agent-event-log

agent-event-log is a skill for Claude Code, Codex from itechmeat/open-second-brain. It costs 266 tokens per session (1,329 once invoked), scanned B, original, MIT.

An append-only event log records operational events in daily Markdown notes. It is designed for durable changes or findings, such as shipped code, configuration edits, documentation updates, and investigation results.

In plain words
What is it for?
Use it to log code changes, bug fixes, deployments, instruction edits, content artifacts, and concrete research conclusions.
Why use it?
It creates a searchable record of important work instead of leaving changes undocumented. Because entries are append-only, earlier records are preserved.

Skill for Claude CodeCodex

Part of the open-second-brain plugin — 6 skills, 8 hooks, 2 MCP servers shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/itechmeat/open-second-brain/agent-event-log
Any agent
npx skills add itechmeat/open-second-brain --skill agent-event-log
Clone the repo
git clone --depth 1 https://github.com/itechmeat/open-second-brain

Made for: Claude Code, Codex.

Or install open-second-brain, the plugin that ships this one along with the rest of its 6 skills, 8 hooks, 2 MCP servers.

Wrote 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.

agentmods badge for agent-event-log

README.md
[![agentmods](https://agentmods.dev/badge/skills/itechmeat/open-second-brain/agent-event-log.svg)](https://agentmods.dev/skills/itechmeat/open-second-brain/agent-event-log)
Your own site
<a href="https://agentmods.dev/skills/itechmeat/open-second-brain/agent-event-log"><img src="https://agentmods.dev/badge/skills/itechmeat/open-second-brain/agent-event-log.svg" alt="Measured on agentmods" height="20"></a>
Per session 266 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,329 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00266 $0.01329
Opus 5 $0.00133 $0.00665
Sonnet 5 $0.00053 $0.00266
Haiku 4.5 $0.00027 $0.00133

Measured 3d ago against content hash 1c9385e52fe3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

agent-event-log scanned grade B with 1 finding 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 3d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

- **Config / deployment:** any change to `config.yaml`, `~/.codex/config.toml`, systemd unit, Caddy snippet, environment variable, secret rotation, infra rollout.
docs/legacy-skills/agent-event-log/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Event Log

Open Second Brain ships an event_log_append tool (via the MCP server registered by this plugin) that records what happened, when, and which agent did it. The tool writes one line into the day's Markdown note (<vault>/Daily/YYYY.MM.DD.md) under a ## Raw events heading.

When to call event_log_append

Call it once per durable artifact produced in the current turn. A durable artifact is anything you would want to find again by searching the vault tomorrow, next week, or six months from now. Concrete triggers:

  • Code: code shipped, bug fixed, refactor merged, dependency bumped, schema migration applied.
  • Config / deployment: any change to config.yaml, ~/.codex/config.toml, systemd unit, Caddy snippet, environment variable, secret rotation, infra rollout.
  • Instructions / docs: edit to CLAUDE.md, AGENTS.md, project README, plugin docs, system prompt, runbook, onboarding guide.
  • Content artifacts: new post draft, documentation page, marketing copy, release notes, public-facing communication.
  • Research / investigation findings: a concrete answer, root cause, design decision, or trade-off resolution. Not the act of searching — the conclusion you reached.
  • External-fact discoveries: a CLI now requires a flag it didn't before, an API rejects a payload it used to accept, a documented behavior diverges from observed behavior. Worth logging because the next session won't re-discover it.

When NOT to call it

  • Pure discussion or brainstorming with no conclusion.
  • Read-only queries (running git log, o2b status, vault_health, second_brain_query).
  • Planning that has not yet produced a written artifact.
  • Acknowledgement-only replies ("ok", "got it").

If you are unsure: ask yourself "would future-me want to find this in the log by searching for it later?". If yes, call the tool.

How to call it

The MCP server resolves the agent identity from ~/.config/open-second-brain/config.yaml automatically; you do not pass agent unless you are deliberately logging on someone else's behalf. Pass only message:

Read the full file on GitHub · 75 lines

Changes

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.

  1. 3d ago First seen · 75 lines · 266 tokens per session scan B 1c9385e52fe3

Subscribe to this mod's changes

agent-event-log is a skill published in the GitHub repository itechmeat/open-second-brain (385 stars, last pushed 6d ago), licensed MIT. It adds 266 tokens to every session and 1,329 once invoked, about $0.0013 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens

chat-perf

Run chat perf benchmarks and memory leak checks against the local dev build or any published VS Code version. Use when investigating chat rendering regressions, validating perf-sensitive changes to chat UI, or checking for memory leaks in the chat response pipeline.

microsoft/vscode · 51 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens