Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/chrisgreenx-ctrl/serena/claude-mdgit clone --depth 1 https://github.com/chrisgreenx-ctrl/serenaWrote 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/chrisgreenx-ctrl/serena/claude-md)<a href="https://agentmods.dev/instructions/chrisgreenx-ctrl/serena/claude-md"><img src="https://agentmods.dev/badge/instructions/chrisgreenx-ctrl/serena/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 | $0.01111 | $0.01111 |
| Opus 5 | $0.00556 | $0.00556 |
| Sonnet 5 | $0.00222 | $0.00222 |
| Haiku 4.5 | $0.00111 | $0.00111 |
Grade A, and why
serena 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 3d 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.
This is a copy
100% identical to serena CLAUDE.md — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 114 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.
Development Commands
Essential Commands (use these exact commands):
uv run poe format- Format code (BLACK + RUFF) - ONLY allowed formatting commanduv run poe type-check- Run mypy type checking - ONLY allowed type checking commanduv run poe test- Run tests with default markers (excludes java/rust by default)uv run poe test -m "python or go"- Run specific language testsuv run poe test -m vue- Run Vue testsuv run poe lint- Check code style without fixing
Test Markers: Available pytest markers for selective testing:
python,go,java,rust,typescript,vue,php,perl,powershell,csharp,elixir,terraform,clojure,swift,bash,ruby,ruby_solargraphsnapshot- for symbolic editing operation tests
Project Management:
uv run serena-mcp-server- Start MCP server from project rootuv run index-project- Index project for faster tool performance
Always run format, type-check, and test before completing any task.
Architecture Overview
Serena is a dual-layer coding agent toolkit:
Core Components
1. SerenaAgent (src/serena/agent.py)
- Central orchestrator managing projects, tools, and user interactions
- Coordinates language servers, memory persistence, and MCP server interface
- Manages tool registry and context/mode configurations
2. SolidLanguageServer (src/solidlsp/ls.py)
- Unified wrapper around Language Server Protocol (LSP) implementations
- Provides language-agnostic interface for symbol operations
- Handles caching, error recovery, and multiple language server lifecycle
3. Tool System (src/serena/tools/)
- file_tools.py - File system operations, search, regex replacements
- symbol_tools.py - Language-aware symbol finding, navigation, editing
- memory_tools.py - Project knowledge persistence and retrieval
- config_tools.py - Project activation, mode switching
- workflow_tools.py - Onboarding and meta-operations
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.
- 3d ago First seen · 114 lines · 1,111 tokens per session scan A 334c449c8138
serena CLAUDE.md is an instructions file published in the GitHub repository chrisgreenx-ctrl/serena (0 stars, last pushed 8mo ago), licensed MIT. It adds 1,111 tokens to every session, about $0.0056 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to serena CLAUDE.md, differing in 0 lines, and is treated as a copy.
Other instructions, from other repositories
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AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
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vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
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Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.