cid-capability-safety

cid-capability-safety is a skill for Claude Code, Codex from PlamenTSV/plamen. It costs 28 tokens per session (1,537 once invoked), scanned A, original, MIT.

A security review guide for DAML contracts that use ContractId values, which identify specific contracts and can be used to fetch or exercise them. It checks whether those identifiers are properly tied to the intended operation.

In plain words
What is it for?
Auditing choices that accept, fetch, exercise, convert, whitelist, or configure ContractId values.
Why use it?
It helps find cases where a caller can supply the wrong contract, missing configuration causes a check to fail open, or stale identifiers stop an operation from working.

Skill for Claude CodeCodex

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

Good fit Auditing choices that accept, fetch, exercise, convert, whitelist, or configure ContractId values.

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Install with agentmods
npx agentmods add skills/plamentsv/plamen/cid-capability-safety
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 cid-capability-safety
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 cid-capability-safety

README.md
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Your own site
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Your own site · 80×15
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Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,537 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
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 $0.00028 $0.01537
Opus 5 $0.00014 $0.00768
Sonnet 5 $0.00006 $0.00307
Haiku 4.5 $0.00003 $0.00154

Measured 9d ago against content hash f65a91e300d4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

cid-capability-safety 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 9d 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/daml/cid-capability-safety/SKILL.md · 83 lines

How it starts

The opening of the file, as written. The whole thing — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CID_CAPABILITY_SAFETY Skill (DAML)

Trigger Pattern: Always required for DAML audits Inject Into: Breadth agents, depth-external, depth-edge-case Finding prefix: [DML-CC-N] Rules referenced: R4, R8, R12

A ContractId t is a DAML-distinctive capability: holding one lets a party fetch/exercise the referenced contract. When a choice accepts a ContractId as an argument, that CID is attacker-chosen unless the body re-binds it to the operation. The four high-yield bug shapes: (1) caller-supplied CID not bound to the operation (caller passes a lookalike), (2) a config/whitelist CID that is missing → the choice fails open, (3) a hardcoded/stale config CID that has been archived → the choice bricks, (4) wrong-CID / type confusion via unchecked fromInterfaceContractId coercion.

1. Caller-Supplied CID Inventory

For every choice that takes a ContractId argument, determine whether the body binds it to the operation:

Template.Choice CID Arg Fetched/Exercised? Bound To Operation? Binding Check Finding?
{T.C} cid : ContractId T2 YES/NO YES/NO assertMsg ... (fetched.owner == this.owner) / NONE [DML-CC-N] if unbound

Critical patterns to flag:

  • A choice that fetch cid and then acts on the fetched contract's fields without asserting the fetched contract relates to this (e.g., same owner, same asset, expected template) — caller passes any CID they can see ([ELEVATE:CID_BINDING]).
  • A choice that exercises a caller-supplied CID to move value, with no check that the CID is the intended counterparty contract.

DAML note: fetch cid succeeds for ANY contract the exercising party is a stakeholder of (or that is divulged). There is no implicit "this is the right contract" guarantee — the body MUST assert the relationship.

2. Config / Whitelist CID Fail-Open

A choice that looks up a config or whitelist contract by CID and proceeds when it is absent fails open.

Read the full file on GitHub · 83 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. 9d ago First seen · 83 lines · 28 tokens per session scan A f65a91e300d4

Subscribe to this mod's changes

cid-capability-safety is a skill published in the GitHub repository PlamenTSV/plamen (294 stars, last pushed yesterday), licensed MIT. It adds 28 tokens to every session and 1,537 once invoked, about $0.0001 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.