About johnnydecimal
A skill for working with Johnny.Decimal documentation and JDex notes. It directs the user to retrieve authoritative guidance from the `jd` MCP server and describes number notation and note conventions.
Key features
- 01Guidance to query documentation pages
- 02Explanation of SYS.AC.ID notation
- 03Rules for reserved zero numbers
- 04JDex note structure and metadata
Use cases
- 01Looking up Johnny.Decimal conventions
- 02Creating or interpreting JDex entries
MCP support
The skill relies on the `jd` MCP server for Johnny.Decimal documentation. It instructs users to call `list_documentation` and then `get_documentation` with a relevant slug.
Install
Copy the command and run it in a terminal.
npx skills add https:/ / github.com/ johnnydecimal/ skills --skill johnnydecimalAfter installing, type/johnnydecimalin Claude Code to confirm it loaded.
Bundled filesagents/openai.yaml
Details
From the project READMEWhere the knowledge lives
Johnny.Decimal documentation lives on the jd MCP server, not in this file. This file holds two things only: enough vocabulary to read a number, and the JDex note conventions the server does not publish.
Do not answer a question about how Johnny.Decimal works from memory. Call list_documentation once to see every page, then get_documentation with the slug you need. The pages cover areas and categories, IDs, headers, AC.ID notation, the standard zeros, the JDex, naming files, subfolder patterns, the inbox and archive, multiple systems, and extend-the-end.
If the server is not connected, say so once, then answer from what is below and mark anything beyond it as uncertain.
Reading a number
SYS.AC.ID, e.g.D25.11.11.SYSis the system identifier and is usually left off.ACis the area-category pair.11is a category. It sits in an area, a range of ten,10-19.IDis the two digits after the decimal.11.11is an ID. IDs hold the content.- In the abstract,
AC.IDmeans any ID,11.IDmeans any ID in category11,1C.IDmeans any ID in area10-19, andA0means any category ending in0.
Numbers ending in zero are reserved for system management. 00-09, A0, and AC.00 to AC.09 are never filing destinations. This is why IDs start at 11.11.
An ID can be extended with a +, e.g. 12.34+ Child's health. Read it as a child of 12.34, or as an item that repeats across the system.
The JDex
The JDex is the index: one note per ID, the master record of every ID in a system. It is usually an Obsidian or Bear vault. Creating the note is what creates the ID.
Note structure
This is the user's own convention. The server does not publish it. Assume a Markdown tool where the note's H1 comes from the filename.
- An optional description on the first line. It starts with
>and is followed by a blank line. - Metadata key/value pairs. The key, a colon, then the values on indented bullets below it.
- A blank line, a Markdown
---, and another blank line. - The user's freeform notes. This is where you write.
Some users prefer proper YAML frontmatter for the metadata. Follow whatever the neighbouring notes do.
Standard metadata properties
Data:— freeform text saying where the data for this ID lives.Related:— wiki-links to other notes. Link from the lower number to the higher, e.g. from11.11to99.99. The JDex software provides backlinks, so never write the reverse link.URL:— a URL.
An example entry
> A short description of what this ID represents.
- Data:
- Folder in Dropbox.
- Related:
- [[56.78 Another relevant ID]]
- URL:
- https://example.com
---
## My notes
- Freeform notes go here. This is the main body of the entry.
- Any format the user likes.
- Typically bullet points.