A plugin that records a file’s SHA-256 fingerprint on Polygon, a blockchain network, through the ProofLedger API, and stores the resulting proof bundle. It can also check files against bundles without a network connection.

Use it for file timestamping, proof-of-existence checks, and verification of documents, build artifacts, or releases.

It lets you prove when an exact file existed while keeping the file contents on your machine. Offline checking can show whether the file has changed since it was recorded.

proofledger — Plugin for Claude Code by Fulcrum-Enterprises

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/Fulcrum-Enterprises/verify-proof

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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/fulcrum-enterprises/verify-proof/claude-plugin/github.svg)](https://agentmods.dev/plugins/fulcrum-enterprises/verify-proof/claude-plugin)

Your own site

<a href="https://agentmods.dev/plugins/fulcrum-enterprises/verify-proof/claude-plugin"><img src="https://agentmods.dev/badge/plugins/fulcrum-enterprises/verify-proof/claude-plugin/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.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/fulcrum-enterprises/verify-proof/claude-plugin"><img src="https://agentmods.dev/badge/plugins/fulcrum-enterprises/verify-proof/claude-plugin.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 2 skills, 1 MCP server cost 124 tokens a session between them.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

proofledger 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 today.

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-plugin/.claude-plugin/plugin.json · 27 lines

What it actually says

{
  "name": "proofledger",
  "displayName": "ProofLedger",
  "version": "0.1.3",
  "description": "Anchor a file's SHA-256 hash on Polygon through the ProofLedger API, save its proof bundle, and verify files against bundles offline. Only the hash leaves your machine, plus the file name unless you ask Claude not to send it.",
  "author": {
    "name": "ProofLedger",
    "url": "https://proofledger.io"
  },
  "homepage": "https://proofledger.io",
  "repository": "https://github.com/Fulcrum-Enterprises/verify-proof",
  "license": "MIT",
  "keywords": [
    "proof-of-existence",
    "timestamp",
    "blockchain",
    "polygon",
    "sha256",
    "verify",
    "mcp"
  ],
  "documentationUrl": "https://github.com/Fulcrum-Enterprises/verify-proof/tree/main/claude-plugin",
  "supportUrl": "https://proofledger.io/support.html",
  "privacyPolicyUrl": "https://proofledger.io/privacy.html",
  "termsOfServiceUrl": "https://proofledger.io/terms.html"
}

Contents

What it installs

The manifest is a name and a version. 2 skills, 1 MCP server travel with it, and installing the plugin installs all of them — 124 tokens a session between them. Each is measured on its own page, and each can be installed alone.

Files

What ships with it

1 file beside plugin.json 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.

icon.png 308 KB

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.

today Changed · +13 lines 3dcdef5a3cc1
2d ago First seen · 14 lines scan A 8477b4e60b6d

Subscribe to this mod's changes

proofledger is a plugin published in the GitHub repository Fulcrum-Enterprises/verify-proof (0 stars, last pushed yesterday), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-10-17.

Web3 and blockchain blockchain cli cryptography merkle-tree polygon proof-of-existence

portal

Query blockchain data across 130+ networks with SQD Portal, including Ethereum, Base, Solana, Polkadot, Bitcoin, Tron, and Hyperliquid. The SQD plugin also includes Pipes SDK and Squid SDK skills for building, migrating, troubleshooting, and improving blockchain data projects.

subsquid-labs/portal-mcp-server · not measured

proofledger

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What it installs

What ships with it

What this file has done since we first saw it

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