grafema: Skill for Claude Code

.claude/skills/rfdb-datalog-hash-join-shared-var/SKILL.md

rfdb-datalog-hash-join-shared-var is a skill for Claude Code from Disentinel/grafema. It costs 213 tokens per session (1,125 once invoked), scanned A, original, no licence file.

A repair guide for incorrect RFDB Datalog results when two graph patterns use the same variable in opposite directions.

In plain words
What is it for?
It is for diagnosing and fixing shared-variable hash joins in RFDB Datalog queries.
Why use it?
It helps resolve silent query errors where a rule returns structurally wrong matches, such as false self-loop results.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is Disentinel/grafema's own configuration. It tells Claude Code how to work on grafema itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything grafema configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Disentinel/grafema. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/Disentinel/grafema/main/.claude/skills/rfdb-datalog-hash-join-shared-var/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/Disentinel/grafema

Made for: Claude Code.

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 rfdb-datalog-hash-join-shared-var

README.md
[![agentmods](https://agentmods.dev/badge/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var/github.svg)](https://agentmods.dev/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var)
Your own site
<a href="https://agentmods.dev/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var"><img src="https://agentmods.dev/badge/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var/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.

agentmods 80×15 button for rfdb-datalog-hash-join-shared-var

Your own site · 80×15
<a href="https://agentmods.dev/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var"><img src="https://agentmods.dev/badge/skills/disentinel/grafema/rfdb-datalog-hash-join-shared-var.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 213 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,125 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.
Origin unknown 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 $0.00213 $0.01125
Opus 5 $0.00106 $0.00562
Sonnet 5 $0.00043 $0.00225
Haiku 4.5 $0.00021 $0.00112

Measured 11d ago against content hash af5a1a05d084, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

rfdb-datalog-hash-join-shared-var 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 11d 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.

.claude/skills/rfdb-datalog-hash-join-shared-var/SKILL.md · 110 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 11d ago First seen · 110 lines · 213 tokens per session scan A af5a1a05d084

Subscribe to this mod's changes

rfdb-datalog-hash-join-shared-var is a skill published in the GitHub repository Disentinel/grafema (36 stars, last pushed 18d ago), with no licence file. It adds 213 tokens to every session and 1,125 once invoked, about $0.0011 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 2026-08-30.