capsule-knowledge

Guidance for using FragCap commands to search and save reusable technical knowledge capsules. FragCap is a system for recording problem-solving experiences for later reuse.

In plain words
What is it for?
Use it to search for similar technical problems or decide when to suggest creating an English-language capsule after solving a non-trivial issue.
Why use it?
It helps developers find solutions others have documented and recognise when a resolved problem is worth preserving as a capsule.

Skill for Claude CodeCodex

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/fragcap/plugin/capsule-knowledge
Any agent
npx skills add fragcap/plugin --skill capsule-knowledge
Clone the repo
git clone --depth 1 https://github.com/fragcap/plugin

Made for: Claude Code, Codex.

Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,045 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00027 $0.01045
Opus 5 $0.00014 $0.00522
Sonnet 5 $0.00005 $0.00209
Haiku 4.5 $0.00003 $0.00104

Measured yesterday against content hash 77801a0527f2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

capsule-knowledge 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 yesterday.

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.

skills/capsule-knowledge/SKILL.md · 112 lines

How it starts

The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.

FragCap Capsule Knowledge

The FragCap plugin is available in this session.

When to Proactively Search Capsules

Trigger a /fragcap:search when the user's message implies they want to know about others' experiences. This includes (but is not limited to):

  • "has anyone else encountered this"
  • "has anyone had the same experience"
  • "how did others solve this"
  • "anyone with a similar experience"
  • "am I the only one hitting this"
  • "has anyone hit this pitfall before"
  • Any phrasing — in any language — that asks whether other people have faced, solved, or documented a similar problem

When triggered, extract the core technical problem from the conversation context and use it as the search query for /fragcap:search. Present the results naturally — e.g., "I found some capsules from other developers who hit similar issues."

When to Suggest Creating a Capsule

After the user resolves a non-trivial problem, you may suggest (not auto-create) drafting a capsule if the solution meets the quality criteria below. Never push without the user's explicit approval.

⚠️ Language Requirement: All capsules MUST be written in English — including problem, solution, pitfalls, attempts, tags, and update notes. Even if the user's conversation is in another language, always generate and push capsule content in English.

Capsule Format

Each capsule is a SKILL.md file — a markdown document with YAML frontmatter that Claude Code can load directly as a skill. Example:

---
id: pgbouncer-pool-202604-a1b2c3d4
description: "Connection pool exhaustion under load with PgBouncer"
tags: ["postgres", "pgbouncer", "connection-pool"]
status: resolved
visibility: anonymous
author: "gh:anonymous-1368de02"
created_at: 2026-04-04T12:00:00.000Z
updated_at: 2026-04-04T12:00:00.000Z
---

# Pgbouncer

## When to Activate

Use this capsule when encountering: Connection pool exhaustion under load with PgBouncer

## Problem

Connection pool exhaustion under load with PgBouncer in production.

## What Does NOT Work

- **Increased pool_size to 200** — Delayed but didn't fix
- **Switched to transaction pooling mode** — Broke prepared statements

## Pitfalls

- PgBouncer silently drops idle connections after server_idle_timeout

## Fix

Set server_idle_timeout=0 and use client-side keepalive instead.

Read the full file on GitHub · 112 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. yesterday First seen · 112 lines · 27 tokens per session scan A 77801a0527f2

Subscribe to this mod's changes

capsule-knowledge is a skill published in the GitHub repository fragcap/plugin (2 stars, last pushed 5mo ago), licensed MIT. It adds 27 tokens to every session and 1,045 once invoked, about $0.0001 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.

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