leslie-lamport

leslie-lamport is an agent for Claude Code from dtannen/icon-agents. It costs 52 tokens per session (1,988 once invoked), scanned A, original, no licence file.

A formal-methods guide focused on mathematical specifications and distributed algorithms, which coordinate computers that communicate over a network. It also draws on TLA+, a language for describing and checking system behaviour.

In plain words
What is it for?
Use it to specify system behaviour, analyse distributed algorithms, check correctness, and describe properties that a system must always preserve.
Why use it?
It helps reason precisely about whether distributed systems behave correctly, including under unusual timing or failure conditions.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

Good fit Use it to specify system behaviour, analyse distributed algorithms, check correctness, and describe properties that a system must always preserve.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/dtannen/icon-agents/leslie-lamport
Install

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.

Clone the repo
git clone --depth 1 https://github.com/dtannen/icon-agents

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.

agentmods badge for leslie-lamport

README.md
[![agentmods](https://agentmods.dev/badge/agents/dtannen/icon-agents/leslie-lamport/github.svg)](https://agentmods.dev/agents/dtannen/icon-agents/leslie-lamport)
Your own site
<a href="https://agentmods.dev/agents/dtannen/icon-agents/leslie-lamport"><img src="https://agentmods.dev/badge/agents/dtannen/icon-agents/leslie-lamport/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.

agentmods 80×15 button for leslie-lamport

Your own site · 80×15
<a href="https://agentmods.dev/agents/dtannen/icon-agents/leslie-lamport"><img src="https://agentmods.dev/badge/agents/dtannen/icon-agents/leslie-lamport.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 52 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,988 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00052 $0.01988
Opus 5 $0.00026 $0.00994
Sonnet 5 $0.00010 $0.00398
Haiku 4.5 $0.00005 $0.00199

Measured 10d ago against content hash 58c8202695f8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

leslie-lamport 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 10d 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/agents/leslie-lamport.md · 243 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 10d ago First seen · 243 lines · 52 tokens per session scan A 58c8202695f8

Subscribe to this mod's changes

leslie-lamport is an agent published in the GitHub repository dtannen/icon-agents (22 stars, last pushed 1y ago), with no licence file. It adds 52 tokens to every session and 1,988 once invoked, about $0.0003 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.