What is sabela CLAUDE.md?

Repository guidance for Sabela, a web-based notebook where executable Haskell code is mixed with Markdown prose. It covers running, testing, linting, formatting, and frontend development.

Use it when starting Sabela, running its HSpec tests, checking Haskell with HLint, formatting Haskell or frontend files, or working on the web interface.

It puts the project’s build and quality checks in one place, so contributors know how to run changes and verify them.

How DataHaskell/sabela configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to DataHaskell/sabela. 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/DataHaskell/sabela/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/DataHaskell/sabela

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/datahaskell/sabela/claude-md/github.svg)](https://agentmods.dev/instructions/datahaskell/sabela/claude-md)

Your own site

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

Per session 2,583 This file is loaded in full into every session.

When invoked 2,583 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	$0.02583	$0.02583
Opus 5.5	$0.01033	$0.01033
Sonnet 5.5	$0.00517	$0.00517
Haiku 4.5	$0.00258	$0.00258

Measured 6d ago against content hash 45bc919a97ee, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

sabela 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 6d 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 · 196 lines

How it starts

The opening of the file, as written. The whole thing — 196 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.

Project Overview

Sabela is a reactive notebook environment for Haskell — a web-based IDE where users write executable Haskell code mixed with Markdown prose. Notebooks are stored as plain Markdown files. The name means "to respond" in Ndebele, reflecting its reactive execution model.

Commands

# Build and run
cabal run                                  # Starts server on localhost:3000
cabal run sabela -- 3000 .                  # sabela [--host H] <port> <work-dir> [global-file] [extra-pkgs...]
                                           # binds 127.0.0.1 by default (or SABELA_HOST); off loopback every
                                           # route needs SABELA_TOKEN (generated + printed if unset)

# Tests
cabal test                                 # Runs HSpec test suite

# Lint and format
./scripts/lint.sh                          # HLint on src/, app/, test/
./scripts/lint.sh --fix                    # Auto-fix lint issues on edited files
./scripts/format.sh                        # fourmolu (Haskell) + prettier (frontend)
./scripts/format.sh --haskell-only         # Skip the prettier pass
./scripts/format.sh --frontend-only        # Only static/*.{html,js,mjs,css}
./scripts/format.sh --check                # Dry-run; non-zero exit on drift

Frontend (modular sources → bundled embeds)

The three served pages — static/index.html (the editor), static/dashboard.html, and static/slideshow.html — are generated build artifacts. The binary embeds them verbatim via Template Haskell (embedFile in Sabela.Server.Static), so the single executable still ships fully self-contained with no runtime asset fetches. Do not hand-edit those files; edit the sources and rebuild.

Layout

The editable sources live under static/src/<page>/:

static/src/index/
  index.html          # shell: <head>/<body> markup + ordered <link>/<script>/include refs
  css/*.css           # style partials, inlined in order (cascade preserved)
  js/*.js             # script partials, inlined in order (one shared global scope)
  html/icons.svg      # inline SVG icon sprite (an asset; inlined, not fetched)
  html/modals.html    # body markup fragment

Read the full file on GitHub · 196 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.

6d ago Changed · +2 lines · +46 tokens per session 45bc919a97ee
17d ago Changed · +13 lines · +171 tokens per session 10f11c449265
2mo ago First seen · 181 lines · 2,366 tokens per session scan A 142ad30e1d8f

Subscribe to this mod's changes

sabela CLAUDE.md is an instructions file published in the GitHub repository DataHaskell/sabela (117 stars, last pushed 6d ago), licensed MIT. It adds 2,583 tokens to every session, about $0.0103 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.

sabela CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
sabela CLAUDE.mdDataHaskell/sabela	Instructions file	117	6d ago	MIT	A	2,583	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

sabela: Instructions file for Claude Code