prime-core

prime-core is a command for Claude Code from mort-lab/excel-mcp. It costs 0 tokens per session (123 once invoked), scanned A, a copy of primer, MIT.

A command that reads a project's structure, documentation, source files, dependencies, and configuration to explain how the project works.

In plain words
What is it for?
Use it at the start of work on an unfamiliar codebase to identify important files, dependencies, configuration, and the project's overall organization.
Why use it?
It gives a coding agent the background it needs before making changes, reducing misunderstandings about files and project purpose.

Command for Claude Code

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 commands/mort-lab/excel-mcp/prime-core
Clone the repo
git clone --depth 1 https://github.com/mort-lab/excel-mcp

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 prime-core

README.md
[![agentmods](https://agentmods.dev/badge/commands/mort-lab/excel-mcp/prime-core.svg)](https://agentmods.dev/commands/mort-lab/excel-mcp/prime-core)
Your own site
<a href="https://agentmods.dev/commands/mort-lab/excel-mcp/prime-core"><img src="https://agentmods.dev/badge/commands/mort-lab/excel-mcp/prime-core.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 123 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod 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 $0.00000 $0.00123
Opus 5 $0.00000 $0.00062
Sonnet 5 $0.00000 $0.00025
Haiku 4.5 $0.00000 $0.00012

Measured 4d ago against content hash eef92885dd46, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prime-core 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 4d 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.

Origin

This is a copy

86% identical to primer — 6 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/commands/development/prime-core.md · 20 lines

What it actually says

Command for priming Claude Code with core knowledge about your project

Prime Context for Claude Code

Use the command tree to get an understanding of the project structure.

Start with reading the CLAUDE.md file if it exists to get an understanding of the project.

Read the README.md file to get an understanding of the project.

Read key files in the src/ directory

List any additional files that are important to understand the project.

Explain back to me:

  • Project structure
  • Project purpose and goals
  • Key files and their purposes
  • Any important dependencies
  • Any important configuration files
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. 4d ago First seen · 20 lines · 0 tokens per session scan A eef92885dd46

Subscribe to this mod's changes

prime-core is a command published in the GitHub repository mort-lab/excel-mcp (5 stars, last pushed 27d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 123 tokens. A static security scan graded it A with 0 findings. It is 86% identical to primer, differing in 6 lines, and is treated as a copy.