cosmodrome: Instructions file for Claude Code

CLAUDE.md

cosmodrome CLAUDE.md is an instructions file for Claude Code from rinaldofesta/cosmodrome. It costs 2,960 tokens per session, scanned A, original, MIT.

Repository instructions for Cosmodrome, a native macOS terminal emulator for running multiple AI coding agents across projects. They describe its architecture, performance targets, product boundaries, and development principles.

In plain words
What is it for?
Understanding the codebase, making performance-sensitive changes, maintaining terminal and agent-state features, and following the project's Swift, AppKit, Metal, and architecture conventions.
Why use it?
They help contributors preserve the app's focus as a terminal and avoid changes that could slow it down or turn it into an IDE or project manager.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code; mentions Codex.

This is rinaldofesta/cosmodrome's own configuration. It tells Claude Code how to work on cosmodrome itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything cosmodrome configures →

Reuse

Borrowing it

Nothing to install: this file belongs to rinaldofesta/cosmodrome. 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/rinaldofesta/cosmodrome/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/rinaldofesta/cosmodrome

Made for: Claude Code.

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README.md
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Per session 2,960 This file is loaded in full into every session.
When invoked 2,960 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.02960 $0.02960
Opus 5 $0.01480 $0.01480
Sonnet 5 $0.00592 $0.00592
Haiku 4.5 $0.00296 $0.00296

Measured 7d ago against content hash b7fab58cc1c7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

cosmodrome 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 7d 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 · 231 lines

How it starts

The opening of the file, as written. The whole thing — 231 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md — Cosmodrome

What is Cosmodrome

A native macOS terminal emulator for developers who run multiple AI agents (Claude Code, Aider, Codex) in parallel across multiple projects. One window, all projects visible, agent state at a glance.

Built with Swift + AppKit + Metal + libghostty-vt. Not Electron. Not Tauri. Not a wrapper around tmux.

Project Philosophy

We are a terminal. Not an IDE, not an editor, not a file manager. We render terminal output, manage PTY processes, and detect AI agent state. That's it.

Performance is non-negotiable. Every frame under 4ms. Every keystroke under 5ms to screen. If a change makes it slower, revert it. Profile before and after. No exceptions.

Simplicity over cleverness. Two layout modes (grid/focus), not four. Three agent states the user cares about (working/needsInput/error), not seven. One config format (YAML), not two. One Metal view, not N.

Observe, never orchestrate. We watch what agents do and surface it to the developer. We never send input to agents, never auto-trigger actions, never control agent behavior. Read-only observation, always.

Ship, then polish. Phase 0 is a single terminal that renders. Phase 1 adds projects and agents. If it doesn't serve Phase 0-1, it doesn't belong in the codebase yet.

Architecture Overview

Read ARCHITECTURE.md for the full picture. Key points:

  • Terminal backend: TerminalBackend protocol. Current implementation: SwiftTerm (pure Swift, ships now). Future: libghostty-vt (when C API stabilizes).
  • Rendering: Single MTKView for the entire content area. Viewport scissoring per session. Shared glyph atlas. One command buffer per frame.
  • I/O: Single thread with kqueue multiplexing all PTY file descriptors. Agent detection runs inline on output arrival, not on a separate polling thread.
  • State: @Observable objects. No event bus, no Combine, no NotificationCenter for domain events. Direct property mutation, Observation framework propagates to UI.
  • Threading: 2 threads total — main (UI + Metal) and I/O (kqueue + VT parsing + agent detection). GCD for background work (config watching, notifications).

Read the full file on GitHub · 231 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. 7d ago First seen · 231 lines · 2,960 tokens per session scan A b7fab58cc1c7

Subscribe to this mod's changes

cosmodrome CLAUDE.md is an instructions file published in the GitHub repository rinaldofesta/cosmodrome (24 stars, last pushed 4mo ago), licensed MIT. It adds 2,960 tokens to every session, about $0.0148 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 2026-08-30.

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