# ProofCheck (remote · proofcheck.something-agent.workers.dev)

Free x402 offer/receipt checker: verifies signatures and whether the signer fits the host.

- Trust score: 60/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `proofcheck.something-agent.workers.dev`: 60/100 (this document), [markdown](https://verifymcp.io/servers/something-agent-proofcheck/proofcheck.md), [page](https://verifymcp.io/servers/something-agent-proofcheck/proofcheck)

## Channel facts

- Endpoint: `https://proofcheck.something-agent.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 5 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 62/100
  - AI-judged instruction clarity (fair).
  - Tool/resource definitions use about 448 tokens (~89/item across 5 items; 5 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 30/100
  - Stability observed for 9 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 73/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 18% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the ProofCheck MCP server?

ProofCheck is a hosted endpoint at https://proofcheck.something-agent.workers.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http something-agent-proofcheck 'https://proofcheck.something-agent.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "something-agent-proofcheck": {
      "url": "https://proofcheck.something-agent.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "something-agent-proofcheck": {
      "type": "http",
      "url": "https://proofcheck.something-agent.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.something-agent-proofcheck]
url = "https://proofcheck.something-agent.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "something-agent-proofcheck": {
      "type": "remote",
      "url": "https://proofcheck.something-agent.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add something-agent-proofcheck --url 'https://proofcheck.something-agent.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  something-agent-proofcheck:
    url: "https://proofcheck.something-agent.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "something-agent-proofcheck": {
      "Transport": "http",
      "Url": "https://proofcheck.something-agent.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add something-agent-proofcheck -t streamable-http -u 'https://proofcheck.something-agent.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "something-agent-proofcheck": {
      "type": "http",
      "url": "https://proofcheck.something-agent.workers.dev/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 60, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 59, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-01 (score 58, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 57, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-28 (score 56, +1)

- [functional improvement] Stability: unverified → 0.03
- [functional] Server version: 0.1.0 → 0.1.4

### 2026-10-27 (score 55)

First indexed and scored.

## MCP tools (5)

### `verify_offer` (~110 tokens)

Verify an x402 signed offer (EIP-712 or JWS): signature, expiry, match to accepts[], and signer-authorization evidence (payTo, did:web, DNS _controllers, ERC-8004). Free.

Input parameters:

- `accepts` (array): Optional accepts[] from the live 402 to match against
- `offer` (object, required): The offer object: {format, payload?, signature, acceptIndex?}
- `resource_url` (string)
- `trusted_pay_to` (array)

### `verify_receipt` (~101 tokens)

Verify an x402 signed receipt (EIP-712 or JWS) returned in the settlement response: signature, freshness, payer/resource/transaction match, signer-authorization evidence. Free.

Input parameters:

- `max_age_seconds` (number)
- `network` (string)
- `payer` (string)
- `receipt` (object, required)
- `resource_url` (string)
- `transaction` (string)
- `trusted_pay_to` (array)

### `verify_payment_required` (~58 tokens)

Verify every signed offer inside a PaymentRequired object (pass the decoded JSON, or the raw base64 PAYMENT-REQUIRED header). Free.

Input parameters:

- `payment_required` (required): Object or base64/JSON string
- `resource_url` (string)

### `preflight_x402_endpoint` (~66 tokens)

Unpaid preflight of an x402 URL: fetch its 402, summarise accepts[]/extensions, verify any signed offers and report who can vouch for the signer. Never pays. Free.

Input parameters:

- `method` (string)
- `url` (string, required)

### `lookup_erc8004_agent` (~79 tokens)

Read-only ERC-8004 identity lookup (owner, agentWallet, registration file, endpoint-domain verification) on Ethereum, Base, Optimism, Arbitrum, Polygon, BNB, Avalanche, Gnosis, Celo, Linea or Scroll.

Input parameters:

- `agent_id` (string, required)
- `chain_id` (integer, required)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/something-agent-proofcheck/proofcheck#diagnostics

## Score history

- 2026-11-05: 60
- 2026-11-04: 59
- 2026-11-03: 59
- 2026-11-02: 58
- 2026-11-01: 58
- 2026-10-31: 57
- 2026-10-30: 57
- 2026-10-29: 56
- 2026-10-28: 56
- 2026-10-27: 55

## Common questions

### What is the ProofCheck MCP server?

ProofCheck is an MCP server listed in the public MCP registry as io.github.something-agent/proofcheck. Free x402 offer/receipt checker: verifies signatures and whether the signer fits the host. This page covers its hosted endpoint (https://proofcheck.something-agent.workers.dev/mcp).

### Is the ProofCheck MCP server safe to use?

ProofCheck scores 60 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the ProofCheck MCP server expose?

ProofCheck exposes 5 tools: verify_offer, verify_receipt, verify_payment_required, preflight_x402_endpoint, lookup_erc8004_agent. Their descriptions and schemas cost roughly 414 tokens of context every time the server is loaded.

### Does the ProofCheck MCP server require authentication?

No. We connected to ProofCheck without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the ProofCheck MCP server still maintained?

ProofCheck is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://proofcheck.something-agent.workers.dev/mcp
- Repository: https://github.com/something-agent/proofcheck
- Website: https://proofcheck.something-agent.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/something-agent-proofcheck/proofcheck.xml
- Changelog JSON feed: https://verifymcp.io/servers/something-agent-proofcheck/proofcheck.json
- HTML version of this page: https://verifymcp.io/servers/something-agent-proofcheck/proofcheck