What is fixedformat4j CLAUDE.md?

A repository guide for Claude Code covering Java setup, Maven commands, tests, and the modules in a multi-module project.

Setting Java 11, building and installing all modules, running the full test suite, or testing one class or method.

It prevents build and test failures caused by using the wrong Java version or running commands from the wrong place.

How jeyben/fixedformat4j configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to jeyben/fixedformat4j. 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/jeyben/fixedformat4j/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/jeyben/fixedformat4j

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/jeyben/fixedformat4j/claude-md/github.svg)](https://agentmods.dev/instructions/jeyben/fixedformat4j/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/jeyben/fixedformat4j/claude-md"><img src="https://agentmods.dev/badge/instructions/jeyben/fixedformat4j/claude-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/jeyben/fixedformat4j/claude-md"><img src="https://agentmods.dev/badge/instructions/jeyben/fixedformat4j/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 2,452 This file is loaded in full into every session.

When invoked 2,452 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.02452	$0.02452
Opus 5.5	$0.00981	$0.00981
Sonnet 5.5	$0.00490	$0.00490
Haiku 4.5	$0.00245	$0.00245

Measured 2mo ago against content hash 21badcbf1e08, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fixedformat4j 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 2mo 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 · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Java Version

Tests require Java 11. Set JAVA_HOME before running Maven:

# Temurin 11 (installed via brew install --cask temurin@11 or sdkman)
export JAVA_HOME=/Library/Java/JavaVirtualMachines/temurin-11.jdk/Contents/Home

# Or use java_home helper on macOS
export JAVA_HOME=$(/usr/libexec/java_home -v 11)

mvn test

Build and Test Commands

This is a Maven multi-module project. Run from the repo root:

# Build and install all modules
mvn install

# Run all tests
mvn test

# Run tests for the main library only
cd fixedformat4j && mvn test

# Run a single test class
mvn test -pl fixedformat4j -Dtest=TestBigDecimalFormatter

# Run a single test method
mvn test -pl fixedformat4j -Dtest=TestBigDecimalFormatter#testSomeMethod

Project Structure

Four Maven modules:

fixedformat4j/ — the core library (main artifact)
fixedformat4j-processor/ — optional compile-time annotation processor (since 1.9.0); mirrors the statically decidable subset of the runtime validation via the mirror API. Any change to FieldValidator/PatternValidator checks must be mirrored in the processor's FieldChecker/RecordValidator, and vice versa.
fixedformat4j-micrometer/ — optional Micrometer instrumentation module (since 1.9.0); decorator-based, no changes to the core artifact; never add Micrometer hooks to core.
samples/ — usage examples

Version synchronisation: none of the modules declare a <parent>. When bumping the project version, update the <version> element in every module pom.xml (fixedformat4j/pom.xml, fixedformat4j-processor/pom.xml, fixedformat4j-micrometer/pom.xml, samples/pom.xml) in addition to the root pom.xml.

Core production source is under fixedformat4j/src/main/java/com/ancientprogramming/fixedformat4j/.

Architecture

The library maps Java POJOs annotated with @Record and @Field to/from fixed-width flat-file strings.

Read the full file on GitHub · 138 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.

2mo ago First seen · 138 lines · 2,452 tokens per session scan A 21badcbf1e08

Subscribe to this mod's changes

fixedformat4j CLAUDE.md is an instructions file published in the GitHub repository jeyben/fixedformat4j (53 stars, last pushed 6d ago), licensed Apache-2.0. It adds 2,452 tokens to every session, about $0.0098 per session on Opus 5.5. 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.

EDI annotations banking batch-processing fixed-format fixed-length

fixedformat4j CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
fixedformat4j CLAUDE.mdjeyben/fixedformat4j	Instructions file	53	6d ago	Apache-2.0	A	2,452	Claude Code
vibetags copilot-instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	1,282	GitHub Copilot
vibetags com-example-service-OrderService.instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	553	GitHub Copilot
vibetags com-example-service-NewAnnotationsShowcase.instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	437	GitHub Copilot
vibetags com-example-indexed-app-DocumentImportJob.instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	436	GitHub Copilot
vibetags com-example-indexed-core-DocumentIndexEntry.instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	439	GitHub Copilot
vibetags com-example-indexed-core-DocumentRetention.instructions.mdPIsberg/vibetags	Instructions file	25	yesterday	MIT	A	488	GitHub Copilot

fixedformat4j: Instructions file for Claude Code