os-experiment-log

os-experiment-log is a skill for Claude Code from richfrem/agent-plugins-skills. It costs 110 tokens per session (891 once invoked), scanned A, original, MIT.

A persistent folder-based record of AI-agent experiments, with one dated file per run and an index listing all runs. It records both numeric results, such as scores, and qualitative results, such as pass or fail findings.

In plain words
What is it for?
Use it to log verifier, tester, planner, survey, and orchestrator runs, track evaluation outcomes, and review experiment history.
Why use it?
It keeps experiment history in one searchable place instead of scattering results across sessions and tools. The result type tells agents how each entry should be interpreted.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter.

Part of the agent-agentic-os plugin — 25 skills, 4 commands, 6 agents, 3 hooks shipped together

Good fit Use it to log verifier, tester, planner, survey, and orchestrator runs, track evaluation outcomes, and review experiment history.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/richfrem/agent-plugins-skills/os-experiment-log
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.

Any agent
npx skills add richfrem/agent-plugins-skills --skill os-experiment-log
Clone the repo
git clone --depth 1 https://github.com/richfrem/agent-plugins-skills

Made for: Claude Code.

Or install agent-agentic-os, the plugin that ships this one along with the rest of its 25 skills, 4 commands, 6 agents, 3 hooks.

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 os-experiment-log

README.md
[![agentmods](https://agentmods.dev/badge/skills/richfrem/agent-plugins-skills/os-experiment-log.svg)](https://agentmods.dev/skills/richfrem/agent-plugins-skills/os-experiment-log)
Your own site
<a href="https://agentmods.dev/skills/richfrem/agent-plugins-skills/os-experiment-log"><img src="https://agentmods.dev/badge/skills/richfrem/agent-plugins-skills/os-experiment-log.svg" alt="Measured on agentmods" height="20"></a>
Per session 110 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 891 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00110 $0.00891
Opus 5 $0.00055 $0.00445
Sonnet 5 $0.00022 $0.00178
Haiku 4.5 $0.00011 $0.00089

Measured today against content hash 02a790861adc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

os-experiment-log 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 today.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/experiment_log.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

plugins/agent-agentic-os/skills/os-experiment-log/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

The experiment log is the unified cross-cutting record for all agentic-os experiments. One file per run, all files in context/experiment-log/, with index.md as a queryable table of all runs.

context/experiment-log/
  index.md                                     ← one row per run (date, source, target, verdict)
  2026-04-25-verifier-os-architect-round1.md   ← from os-evolution-verifier
  2026-04-25-tester-os-architect.md            ← from os-architect-tester
  2026-04-25-os-improvement-loop-os-eval-runner.md    ← from os-improvement-loop
  2026-04-25-planner-0024.md                   ← from os-evolution-planner
  2026-04-25-survey-session.md                 ← from post_run_survey

Source Types and Result Kinds

Agents must check result_type in a log entry's header before parsing it:

--source-type Produced by result_type Key fields
verifier os-evolution-verifier qualitative PASS/PARTIAL/FAIL counts, HANDOFF_BLOCK validity
tester os-architect-tester qualitative AC-1–4 pass/fail per scenario
orchestrator os-improvement-loop numeric best_score, baseline, delta, KEEP/DISCARD counts
planner os-evolution-planner qualitative workstream count, gaps identified
survey post_run_survey mixed friction item count, north_star metric

Numeric entries (result_type: numeric) carry quantitative metrics suitable for trending and charting. Qualitative entries (result_type: qualitative) carry pass/fail verdicts and gap analysis prose. Mixed entries (result_type: mixed) carry both — agents must check which fields are present before parsing.

Phase 1 — Resolve Mode

Read the argument or invocation context to determine mode:

  • append --source-type TYPE: log a new run from a completed experiment
  • query <term>: search all files in context/experiment-log/ by keyword
  • summary: print aggregate stats across all runs, broken down by source type

Read the full file on GitHub · 74 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. today Changed · -113 lines 02a790861adc
  2. 8d ago First seen · 187 lines · 110 tokens per session scan A f11830458bf1

Subscribe to this mod's changes

os-experiment-log is a skill published in the GitHub repository richfrem/agent-plugins-skills (6 stars, last pushed today), licensed MIT. It adds 110 tokens to every session and 891 once invoked, about $0.0006 per session on Opus 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.