ptb-composability

ptb-composability is a skill for Claude Code, Codex from PlamenTSV/plamen. It costs 43 tokens per session (3,174 once invoked), scanned B, original, MIT.

A Sui Move security-audit guide for Programmable Transaction Blocks, or PTBs. A PTB is a Sui transaction that can combine many function calls and pass results between them atomically.

In plain words
What is it for?
Checking public entry points, multi-call sequences, shared-object access, and atomic read-modify-write behavior.
Why use it?
It helps reveal bugs caused by assuming a public function will run alone or in a fixed order.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Checking public entry points, multi-call sequences, shared-object access, and atomic read-modify-write behavior.

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Install with agentmods
npx agentmods add skills/plamentsv/plamen/ptb-composability
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.

Any agent
npx skills add PlamenTSV/plamen --skill ptb-composability
Clone the repo
git clone --depth 1 https://github.com/PlamenTSV/plamen

Made for: Claude Code, Codex.

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 ptb-composability

README.md
[![agentmods](https://agentmods.dev/badge/skills/plamentsv/plamen/ptb-composability/github.svg)](https://agentmods.dev/skills/plamentsv/plamen/ptb-composability)
Your own site
<a href="https://agentmods.dev/skills/plamentsv/plamen/ptb-composability"><img src="https://agentmods.dev/badge/skills/plamentsv/plamen/ptb-composability/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 ptb-composability

Your own site · 80×15
<a href="https://agentmods.dev/skills/plamentsv/plamen/ptb-composability"><img src="https://agentmods.dev/badge/skills/plamentsv/plamen/ptb-composability.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,174 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Memory Poisoning · line 145
    Skill manipulates agent memory, state, or stored context. Memory corruption can alter personality, override safety rules, or cause unpredictable behavior.
    Fix: Protect agent memory and state from modification by untrusted content. Use read-only memory for critical instructions and validate all state changes.
  • medium Excessive Agency · line 50
    Skill grants unrestricted tool access without appropriate constraints. An agent with unfettered tool access can perform arbitrary actions including file modification, network requests, and code execution.
    Fix: Restrict tool access to only the tools required for the skill's stated purpose. Use an explicit allowlist rather than granting blanket access.
How audits are shown
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 $0.00043 $0.03174
Opus 5 $0.00022 $0.01587
Sonnet 5 $0.00009 $0.00635
Haiku 4.5 $0.00004 $0.00317

Measured 7d ago against content hash eeacf5885862, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

ptb-composability scanned grade B with 1 finding 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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

**Key question for each function**: "If an attacker calls this function as command N in a PTB, and can execute arbitrary commands 1..N-1 before it and N+1..1024 after it, what can go wrong?"
agents/skills/sui/ptb-composability/SKILL.md · 256 lines

How it starts

The opening of the file, as written. The whole thing — 256 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill: PTB_COMPOSABILITY (Sui)

Trigger Pattern: PTB flag (always for Sui -- Programmable Transaction Blocks are the Sui transaction model) Inject Into: Breadth agents, depth-external, depth-state-trace Finding prefix: [PTB-N] Rules referenced: R4, R5, R8, R10, R15

Programmable Transaction Blocks (PTBs) are Sui's transaction composition primitive. A single PTB can contain up to 1024 commands, each calling a different function, with return values routed between commands. This enables atomic multi-step sequences that are fundamentally different from EVM's single-entry-point model. Every public function is a potential PTB command -- there is no "internal only" visibility equivalent to Solidity's internal.

STEP PRIORITY: Steps 1 (Single-Call Assumption Audit) and 4 (Atomic Read-Modify-Write) are where HIGH/CRITICAL severity findings most commonly hide. Do NOT rush these steps. If constrained, skip conditional sections (6, 7) before skipping 1, 3, or 4.


1. Entry Point Inventory

For EVERY public and entry function in the protocol, classify composability:

# Function Module Visibility Returns Value? Takes Shared Obj? Composable in PTB? Notes
1 {func} {mod} public / entry / public(package) YES / NO YES / NO YES / NO {context}

Sui visibility semantics:

  • entry functions: callable from PTB but return values CANNOT be used by subsequent commands (consumed or discarded within the command). Objects can only be transferred, not returned.
  • public functions: fully composable -- return values pass between commands. This is the primary composability surface.
  • public(package): callable only by other modules in the same package. NOT callable from PTB. Safe from external composition.
  • fun (private): Not callable from outside the module. Safe.

Key observation: Any function that is public (not entry, not public(package)) is fully composable. Its return values can be routed to ANY other function in the same PTB.

Read the full file on GitHub · 256 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 · 256 lines · 43 tokens per session scan B eeacf5885862

Subscribe to this mod's changes

ptb-composability is a skill published in the GitHub repository PlamenTSV/plamen (295 stars, last pushed 3d ago), licensed MIT. It adds 43 tokens to every session and 3,174 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.