# Wren Pre-sign Check (remote · wren-presign-check.wrenonbase.workers.dev)

Check a tx, EIP-712 payload, text or Base token before your agent signs. Paid per call over x402.

- Trust score: 69/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `wren-presign-check.wrenonbase.workers.dev`: 69/100 (this document), [markdown](https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check.md), [page](https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check)

## Channel facts

- Endpoint: `https://wren-presign-check.wrenonbase.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.4.0`

## 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**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Nothing on it is marked destructive, but we can't show that an anonymous caller can only read: full credit needs the server to list at least one tool and every tool to be verifiably read-only. We use a best-effort check of tool names and descriptions to tell read-only tools from tools that change things, so some genuinely read-only tools may not get full credit. Names that start with a read verb (get, list, read, search and similar) and accurate readOnlyHint annotations help. Meet that to earn full credit, or require authorisation.
  - 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**: 64/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 924 tokens (~231/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 27/100
  - Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% 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 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the Wren Pre-sign Check MCP server?

Wren Pre-sign Check is a hosted endpoint at https://wren-presign-check.wrenonbase.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 claudeisgod-wren-presign-check 'https://wren-presign-check.wrenonbase.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "claudeisgod-wren-presign-check": {
      "url": "https://wren-presign-check.wrenonbase.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "claudeisgod-wren-presign-check": {
      "type": "http",
      "url": "https://wren-presign-check.wrenonbase.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.claudeisgod-wren-presign-check]
url = "https://wren-presign-check.wrenonbase.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "claudeisgod-wren-presign-check": {
      "type": "remote",
      "url": "https://wren-presign-check.wrenonbase.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add claudeisgod-wren-presign-check --url 'https://wren-presign-check.wrenonbase.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  claudeisgod-wren-presign-check:
    url: "https://wren-presign-check.wrenonbase.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "claudeisgod-wren-presign-check": {
      "Transport": "http",
      "Url": "https://wren-presign-check.wrenonbase.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add claudeisgod-wren-presign-check -t streamable-http -u 'https://wren-presign-check.wrenonbase.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "claudeisgod-wren-presign-check": {
      "type": "http",
      "url": "https://wren-presign-check.wrenonbase.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 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-01 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 66, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-29 (score 65, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-28 (score 65)

First indexed and scored.

## MCP tools (4)

### `presign_check` (~321 tokens)

Pre-sign check

Call before your agent signs anything. Send tx fields (to, data, value, chainId), or typedData (an eth_signTypedData_v4 payload), or untrusted text, with an optional wren-guard policy. Returns block, review or allow, the decoded call and every finding: unlimited approvals, permits, Permit2, setApprovalForAll, EIP-7702 delegation, deployments, injected instructions and, with a policy, unknown recipients, caps and lookalike addresses. Static check, not a simulation. Costs $0.01 USDC on Base per call, paid over x402 (MCP transport): an unpaid call returns a PaymentRequired result, and an x402 MCP client retries with the payment in _meta["x402/payment"]. You sign one USDC authorisation for exactly that price to Wren's wallet: no approvals. Bad input is rejected before anything is charged.

Input parameters:

- `chainId` (string): Chain id, decimal
- `data` (string): Calldata, 0x hex
- `policy` (object): Optional wren-guard config: allowlist, spenders, caps and flags
- `text` (string): Untrusted text that asked for this action, screened for injected instructions
- `to` (string): Destination contract or recipient (0x address); omit for a deployment
- `typedData` (object): eth_signTypedData_v4 payload (instead of a transaction)
- `value` (string): Native value in wei (decimal or 0x hex)

### `screen_text` (~206 tokens)

Prompt-injection screen

Call before your agent acts on untrusted text (a reply, DM, web page, tool output or memory). Returns safe, suspicious or malicious with the matched patterns, after decoding base64, hex, Morse, leetspeak, ROT13, reversed and hidden Unicode. Optional known: your own addresses, to flag poisoned lookalikes. Deterministic rules, no LLM. Costs $0.003 USDC on Base per call, paid over x402 (MCP transport): an unpaid call returns a PaymentRequired result, and an x402 MCP client retries with the payment in _meta["x402/payment"]. You sign one USDC authorisation for exactly that price to Wren's wallet: no approvals. Bad input is rejected before anything is charged.

Input parameters:

- `known` (array): Optional: your own 0x addresses, to flag poisoned lookalikes
- `text` (string, required): The untrusted text to screen (up to 16,384 characters)

### `token_facts` (~192 tokens)

Base token contract facts

Call before your agent approves, receives or sends a Base ERC-20. Returns code size, EIP-7702 delegation, name, symbol, decimals, supply, proxy and upgrade admin, owner or renounced, and which privileged functions the bytecode has (mint, pause, blocklist, fees, limits, trading switch, upgrade). Facts only: no grades, not investment advice. If Base can't be read, nothing is charged. Costs $0.01 USDC on Base per call, paid over x402 (MCP transport): an unpaid call returns a PaymentRequired result, and an x402 MCP client retries with the payment in _meta["x402/payment"]. You sign one USDC authorisation for exactly that price to Wren's wallet: no approvals. Bad input is rejected before anything is charged.

Input parameters:

- `address` (string, required): The token contract's 0x address on Base

### `presign_demo` (~80 tokens)

Free pre-sign example

Free. Runs one fixed example (an unlimited approval, setApprovalForAll, a never-expiring permit, an EIP-7702 delegation, an injected memo or a normal x402 payment) through the same checker, so you can see the report shape before paying for presign_check.

Input parameters:

- `name` (string, required): Which fixed example to run

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check#diagnostics

## Score history

- 2026-11-05: 69
- 2026-11-04: 68
- 2026-11-03: 68
- 2026-11-02: 67
- 2026-11-01: 67
- 2026-10-31: 66
- 2026-10-30: 66
- 2026-10-29: 65
- 2026-10-28: 65

## Common questions

### What is the Wren Pre-sign Check MCP server?

Wren Pre-sign Check is an MCP server listed in the public MCP registry as io.github.claudeisgod/wren-presign-check. Check a tx, EIP-712 payload, text or Base token before your agent signs. Paid per call over x402. This page covers its hosted endpoint (https://wren-presign-check.wrenonbase.workers.dev/mcp).

### Is the Wren Pre-sign Check MCP server safe to use?

Wren Pre-sign Check scores 69 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 Wren Pre-sign Check MCP server expose?

Wren Pre-sign Check exposes 4 tools: presign_check, screen_text, token_facts, presign_demo. Their descriptions and schemas cost roughly 799 tokens of context every time the server is loaded.

### Does the Wren Pre-sign Check MCP server require authentication?

No. We connected to Wren Pre-sign Check without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Wren Pre-sign Check MCP server still maintained?

Wren Pre-sign Check 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.

### What did VerifyMCP test on the Wren Pre-sign Check MCP server?

VerifyMCP ran 12 checks on Wren Pre-sign Check, covering TLS certificate, Authorization, HSTS header, DNSSEC and 8 more. One item could not be completed, a gap on our side rather than a finding about Wren Pre-sign Check: HTTPS. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- Remote endpoint: https://wren-presign-check.wrenonbase.workers.dev/mcp
- Website: https://wren-presign-check.wrenonbase.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check.xml
- Changelog JSON feed: https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check.json
- HTML version of this page: https://verifymcp.io/servers/claudeisgod-wren-presign-check/wren-presign-check