Borrowing it
Nothing to install: this file belongs to fluxon-lang/fluxon. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/fluxon-lang/fluxon/master/CLAUDE.mdgit clone --depth 1 https://github.com/fluxon-lang/fluxonWrote 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.
[](https://agentmods.dev/instructions/fluxon-lang/fluxon/claude-md)<a href="https://agentmods.dev/instructions/fluxon-lang/fluxon/claude-md"><img src="https://agentmods.dev/badge/instructions/fluxon-lang/fluxon/claude-md.svg" alt="Measured on agentmods" height="20"></a>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 | $0.02056 | $0.02056 |
| Opus 5 | $0.01028 | $0.01028 |
| Sonnet 5 | $0.00411 | $0.00411 |
| Haiku 4.5 | $0.00206 | $0.00206 |
Grade A, and why
fluxon 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md — How to work on Fluxon (for AI agents)
This file is for Claude Code and other AI agents. Before making any change to the project, read this file to the end. The goal: get a new agent productive fast, working in the right place and in the right style.
For human contributors:
CONTRIBUTING.md. Runtime internals:ARCHITECTURE.md.
0. What this project is
Fluxon — a backend programming language that AI agents write well. Philosophy:
"The language adapts to the AI, not the AI to the language." One task = one way
(canonical form), few tokens, batteries-included (http/db/ai/ws/...).
This repo has two parts:
runtime/— the language interpreter (Rust, tree-walking). This is where the main work happens. All code, tests, and builds live here.docs/+examples/+research/— the language specification, examples, and how the language was designed (experiments).
1. Language
Write code, comments, commit messages, PR titles/descriptions, and
documentation in English. Technical terms and code identifiers (HashMap,
eval_call, db.tx) stay as-is.
When talking to the user, the agent is language-neutral: reply in whatever language the user writes in. The codebase is English, but the conversation adapts to the user.
Note:
research/and the*.uz.mddocuments are kept in Uzbek on purpose (design history and future multi-language docs) — do not translate them.
2. Where things are (navigation)
Before adding a new battery or making a change, find the relevant file:
| Task | File |
|---|---|
Token types, Token.spaced flag |
runtime/src/token.rs |
| Lexer: INDENT/DEDENT, string interpolation | runtime/src/lexer.rs |
AST nodes (Stmt, Expr) |
runtime/src/ast.rs |
| Parser: precedence climbing, parenless calls | runtime/src/parser.rs |
Value types (Value, NativeFn) |
runtime/src/value.rs |
| Interpreter: scope, control flow, dispatch | runtime/src/interp.rs |
Core modules (str/math/rand/json/time) |
runtime/src/builtins.rs |
http battery (server + client) |
runtime/src/http_mod.rs |
ai battery (LLM — Anthropic Messages API) |
runtime/src/ai_mod.rs |
db battery (SQLite, tx, schema) |
runtime/src/db_mod.rs |
auth battery (JWT HS256 + password hash argon2id) |
runtime/src/auth_mod.rs |
crypto battery (sha256/hmac/b64/hex/uuid) |
runtime/src/crypto_mod.rs |
tui battery (colors + table/box/select/input — CLI UX) |
runtime/src/builtins/tui_mod.rs |
User-module .pkg manifest parsing + load-time validation |
runtime/src/interp/pkg.rs |
| CLI entry point + integration tests | runtime/src/main.rs |
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.
- 8d ago First seen · 181 lines · 2,056 tokens per session scan A 689a552efb51
fluxon CLAUDE.md is an instructions file published in the GitHub repository fluxon-lang/fluxon (5 stars, last pushed 2mo ago), licensed MIT. It adds 2,056 tokens to every session, about $0.0103 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.
Other instructions, from other repositories
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spec-kit AGENTS.md
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