attester

attester is a skill for Claude Code, Codex from maminihds/attester-mcp. It costs 118 tokens per session (2,375 once invoked), scanned A, original, MIT.

A fact-checking skill that verifies software packages, code symbols, citations, agent work, and payment counterparties before they are trusted.

In plain words
What is it for?
Use it before importing a PyPI or npm package, relying on a library symbol, accepting another agent's output, or paying an unfamiliar service.
Why use it?
It reduces the risk of acting on invented package names, unsupported claims, faulty code, or unsafe payment targets.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it before importing a PyPI or npm package, relying on a library symbol, accepting another agent's output, or paying an unfamiliar service.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/maminihds/attester-mcp/attester
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 maminihds/attester-mcp --skill attester
Clone the repo
git clone --depth 1 https://github.com/maminihds/attester-mcp

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin attester/plugin install attester after adding the marketplace above.

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 attester

README.md
[![agentmods](https://agentmods.dev/badge/skills/maminihds/attester-mcp/attester.svg)](https://agentmods.dev/skills/maminihds/attester-mcp/attester)
Your own site
<a href="https://agentmods.dev/skills/maminihds/attester-mcp/attester"><img src="https://agentmods.dev/badge/skills/maminihds/attester-mcp/attester.svg" alt="Measured on agentmods" height="20"></a>
Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,375 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00118 $0.02375
Opus 5 $0.00059 $0.01188
Sonnet 5 $0.00024 $0.00475
Haiku 4.5 $0.00012 $0.00237

Measured 7d ago against content hash 7eac9cd5020e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

attester scanned grade A 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/call.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -X POST https://attester.dev/demo/v1/package/exists \
skills/attester/SKILL.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

attester.dev: verification oracle for agents

attester.dev is a paid HTTP API that returns signed verdicts. Every answer carries an EIP-191 attestation you can verify offline. The free path needs no account and no funded wallet.

When to use this skill

  • Before importing a package name a model suggested. Hallucination rates for suggested packages run 5-20% in published studies.
  • When unsure a function, class, or constant exists in a library version.
  • Before trusting another agent's citations, code, dataset, or summary.
  • Before paying an x402 service you have not paid before.
  • When you want a cited answer instead of a guess. Short version: check first, act second.

Auth: start free

Two free paths exist.

Keyless (oracle endpoints only). The four /v1/* oracle endpoints have /demo/v1/* mirrors that take no headers at all: same pipeline, same signed answers, 25 calls per day per client IP shared across the four, resetting 00:00 UTC. Over quota they return HTTP 429 with the paid route in the body. A valid X-API-Key bypasses the demo quota and is never charged for it.

X-Payer (every paid endpoint). Send X-Payer with any wallet address you control. It keys your free quota; nothing else is needed.

X-Payer: 0x0000000000000000000000000000000000000001

Per-endpoint X-Payer free quotas today: 25 research calls, 10 oracle checks, 5 verify or spend checks, 3 judge gradings or watchtower reports. When a quota runs out the call returns HTTP 402 with payment terms.

Paid paths when you outgrow free quota:

  1. X-API-Key: att_live_... prepaid credits. A human buys a pack at https://buy.stripe.com/bJefZhfGo9Uy6zF9ckaZi00 and claims the key at GET /credits/claim?session_id=cs_.... Balance: GET /credits/balance with the key.
  2. x402 payment per call in USDC on Base, signed by any funded EVM wallet. Use the official x402 Python SDK (x402HttpxClient); the 402, signing, and retry are automatic.

Endpoints and exact calls

Read the full file on GitHub · 218 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. 7d ago First seen · 218 lines · 118 tokens per session scan A 7eac9cd5020e

Subscribe to this mod's changes

attester is a skill published in the GitHub repository maminihds/attester-mcp (0 stars, last pushed 28d ago), licensed MIT. It adds 118 tokens to every session and 2,375 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens

next-partial-prefetching-adoption

Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…

vercel/next.js · 103 tokens

chronicle

Analyze Copilot session history for standup reports, usage tips, session search, and session reindexing. Use when the user asks for a standup, daily summary, usage tips, workflow recommendations, wants to search or find past sessions by keyword/file/PR, wants to reindex their session store, or asks about deleting…

microsoft/vscode · 72 tokens