ctx-index

ctx-index is a skill for Claude Code from mksglu/context-mode. It costs 44 tokens per session (309 once invoked), scanned A, original, no licence file.

An indexing command that adds a local file or directory to context-mode's persistent knowledge base. Indexing prepares content for later search.

In plain words
What is it for?
Use it to index project code or documentation so future searches can return relevant snippets.
Why use it?
It avoids repeatedly rereading the same raw files when you need information from them later.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the context-mode plugin — 9 skills, 3 hooks, 1 MCP server 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/mksglu/context-mode/ctx-index
Any agent
npx skills add mksglu/context-mode --skill ctx-index
Clone the repo
git clone --depth 1 https://github.com/mksglu/context-mode

Made for: Claude Code.

Or install context-mode, the plugin that ships this one along with the rest of its 9 skills, 3 hooks, 1 MCP server.

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 ctx-index

README.md
[![agentmods](https://agentmods.dev/badge/skills/mksglu/context-mode/ctx-index.svg)](https://agentmods.dev/skills/mksglu/context-mode/ctx-index)
Your own site
<a href="https://agentmods.dev/skills/mksglu/context-mode/ctx-index"><img src="https://agentmods.dev/badge/skills/mksglu/context-mode/ctx-index.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 309 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00044 $0.00309
Opus 5 $0.00022 $0.00154
Sonnet 5 $0.00009 $0.00062
Haiku 4.5 $0.00004 $0.00031

Measured 6d ago against content hash 5e49548597a6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

ctx-index 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 6d 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.

skills/ctx-index/SKILL.md · 47 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. 6d ago First seen · 47 lines · 44 tokens per session scan A 5e49548597a6

Subscribe to this mod's changes

ctx-index is a skill published in the GitHub repository mksglu/context-mode (20,365 stars, last pushed yesterday), with no licence file. It adds 44 tokens to every session and 309 once invoked, about $0.0002 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.

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