tla-verify-protocol

A skill for checking a concurrent process with PlusCal, TLA+, and TLC. These are formal tools that describe possible system states and test whether a stated rule holds under defined assumptions.

In plain words
What is it for?
Use it to verify one focused behavior of a concurrent state machine, map the model back to source code, and create deterministic tests.
Why use it?
It can reveal ordering, cancellation, retry, shutdown, or coordination problems that ordinary tests may miss, while keeping the conclusion limited to the model being checked.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/kyleve/stuff/tla-verify-protocol
Any agent
npx skills add kyleve/Stuff --skill tla-verify-protocol
Clone the repo
git clone --depth 1 https://github.com/kyleve/Stuff

Made for: Claude Code, Codex.

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,587 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00105 $0.01587
Opus 5 $0.00053 $0.00794
Sonnet 5 $0.00021 $0.00317
Haiku 4.5 $0.00011 $0.00159

Measured 2d ago against content hash fe8493704757, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tla-verify-protocol 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 2d 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.

.agents/skills/tla-verify-protocol/SKILL.md · 151 lines

How it starts

The opening of the file, as written. The whole thing — 151 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Verify a protocol with PlusCal and TLA+

Verify one narrow temporal claim, not an application. Treat TLC output as evidence about the stated model, bounds, and assumptions. Never present it as proof that the implementation is correct.

Read the repository and affected module instructions before modeling. In this repository, use Where/Specifications/TrackingReconciliation as the worked tooling and documentation reference. Do not copy its state mapping into unrelated protocols.

Establish the verification boundary

  1. Read the production implementation, tests, and callers. Identify every entry point that can participate in the protocol, not only the method named in the request.
  2. State one correctness question in plain language. Define its admission or linearization points, success and failure outcomes, repeated-call behavior, and treatment of work racing with shutdown or cancellation.
  3. Record the source revision and files the model represents. List suspension points, locks, actor reentrancy, tasks, callbacks, persistence boundaries, and environment actions that can change ordering.
  4. If a missing product decision changes the contract materially, stop and request direction. If the logic has no meaningful temporal behavior, explain why TLA+ is the wrong verification tool.

Read references/modeling-checklist.md before authoring any model. Read only the relevant sections of references/protocol-patterns.md for the protocol family being checked.

Build a traceable model

  1. Create a source-correspondence table mapping each model variable and action to production state and code boundaries.
  2. Preserve independently authoritative facts as separate variables. Do not collapse desired, persisted, in-flight, effective, and published state merely because the implementation calls all of them "state."
  3. Make each action genuinely atomic. Split an async function at every await or callback boundary where another action can interleave.
  4. Abstract data values into a small finite set while preserving identity, ordering, duplication, loss, and lifecycle facts relevant to the claim.
  5. Model environment failures and late completions nondeterministically unless the production contract forbids them.

Read the full file on GitHub · 151 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 151 lines · 105 tokens per session scan A fe8493704757

Subscribe to this mod's changes

tla-verify-protocol is a skill published in the GitHub repository kyleve/Stuff (2 stars, last pushed 2d ago), licensed Apache-2.0. It adds 105 tokens to every session and 1,587 once invoked, about $0.0005 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.

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