upjack CLAUDE.md

upjack CLAUDE.md is an instructions file for coding agents from NimbleBrainInc/upjack. It costs 2,010 tokens per session, scanned A, original, Apache-2.0.

Repository instructions for Upjack, a framework for building AI-native applications packaged as MCPB files. They describe its Python and TypeScript libraries, schemas, skills, examples, and relationship and activity features.

In plain words
What is it for?
Use them to develop Upjack applications, validate their package data, work with entity relationships, record activities, and follow the repository's directory structure.
Why use it?
They give agents a map of the framework so they can find the right library, schema, or example when working on an app. They also explain how applications navigate related data and track activity.

Instructions file

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 instructions/nimblebraininc/upjack/claude-md
Clone the repo
git clone --depth 1 https://github.com/NimbleBrainInc/upjack

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 upjack CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/nimblebraininc/upjack/claude-md.svg)](https://agentmods.dev/instructions/nimblebraininc/upjack/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/nimblebraininc/upjack/claude-md"><img src="https://agentmods.dev/badge/instructions/nimblebraininc/upjack/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,010 This file is loaded in full into every session.
When invoked 2,010 The same file — it is already loaded in full.
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 $0.02010 $0.02010
Opus 5 $0.01005 $0.01005
Sonnet 5 $0.00402 $0.00402
Haiku 4.5 $0.00201 $0.00201

Measured 3d ago against content hash b6c2b027f946, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

upjack CLAUDE.md 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 3d 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.md · 179 lines

How it starts

The opening of the file, as written. The whole thing — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.

NimbleBrain Upjack Framework

Declarative AI-native application framework. Apps are MCPB packages with a _meta["ai.nimblebrain/upjack"] extension.

Current version: 0.1.0 Package names: upjack on PyPI, upjack on npm

Directory Layout

lib/python/       Python library (upjack) — source in src/upjack/
lib/typescript/   TypeScript library (upjack) — source in src/
schemas/          JSON Schemas (upjack-entity, upjack-manifest) + validation tooling
skills/           Publishable skills (upjack-app-builder) — symlinked from .claude/skills/
examples/         Reference apps (CRM, Todo, Research Assistant)
website/          Documentation site (Astro/Starlight) — upjack.dev
workspace/        Runtime entity data (gitignored, created at runtime)

Key Modules (Python)

Module Purpose
upjack.relations Write-time reverse relationship index — query_reverse(), rebuild_index()
upjack.activity Activity entity tracking — log_activity(), get_activities()

Graph Traversal (UpjackApp)

Methods for navigating entity relationships:

  • query_by_relationship(entity_type, rel, target_id, filter?, limit?) — reverse index lookup (e.g., find all deals linked to a contact)
  • get_related(entity_id, rel?, direction?) — follow edges forward or reverse, returns resolved entities
  • get_composite(entity_type, entity_id, depth?) — load entity + all related in one call; _related key contains forward (rel) and reverse (~rel) edges

CRUD hooks: on_relationships_changed callback fires on create_entity, update_entity, delete_entity — UpjackApp auto-wires this to maintain the reverse index.

Activity Tracking

Opt-in via "activities": true in manifest _meta["ai.nimblebrain/upjack"] extension.

  • log_activity(subject_id, action, detail?) — creates an activity entity with a subject relationship
  • get_activities(subject_id, action?, limit?) — reverse index query for a subject's activities
  • Activity schema: action (string, required), detail (object, optional)

Read the full file on GitHub · 179 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. 3d ago First seen · 179 lines · 2,010 tokens per session scan A b6c2b027f946

Subscribe to this mod's changes

upjack CLAUDE.md is an instructions file published in the GitHub repository NimbleBrainInc/upjack (9 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 2,010 tokens to every session, about $0.0100 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.