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.
Available components
Last scanned (6 hours ago)
Scores higher than 54% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Crypto and Web3
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. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- 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. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability64
- AI-judged instruction clarity (good).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management27
- Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Checks we ran (12)
- TLS certificate
- Authorization
- HSTS header
- DNSSEC
- Transport
- Schema quality
- Stability
- Tool coverage
- Injection markers
- Destructive annotations
- Judged manipulation
- MCP protocol
Checks we could not complete (1)
These are gaps on our side, not findings about this hosted endpoint. We only credit what we can confirm, so a category made up entirely of them scores 0.
- HTTPS in Endpoint SecurityHTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
Does not apply to this hosted endpoint (2)
- Supply Chain SecurityScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
- Provenance & TransparencyScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
The score does not measure everything. What the score does not measure →
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 5 Nov 26 +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.
- 3 Nov 26 +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.
- 1 Nov 26 +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.
- 30 Oct 26 +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.
- 29 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 28 Oct 26 65
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://wren-presign-check.wrenonbase.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=wrenonbase.workers.dev | CN=YE1,O=Let's Encrypt,C=US | 20 Oct 2026 | 18 Jan 2027 | ECDSA 256 | ECDSA-SHA384 | 6c234104df1860e15a3e7b6dbba54d9cbca |
| SANs: *.wrenonbase.workers.dev, wrenonbase.workers.dev | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of wren-presign-check.wrenonbase.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | Trust anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | DS published | 60074 | 8 | Verified |
| workers.dev. | No DS | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| x-content-type-options | nosniff |
| referrer-policy | no-referrer |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://wren-presign-check.wrenonbase.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://wren-presign-check.wrenonbase.workers.dev/mcp | Inconclusive | 405 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
presign_check Pre-sign check ~321
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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) |
No output schema declared.
No examples provided.
presign_demo Free pre-sign example ~80
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.
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | Which fixed example to run |
No output schema declared.
No examples provided.
screen_text Prompt-injection screen ~206
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.
| Name | Type | Req | Description |
|---|---|---|---|
| known | array | – | Optional: your own 0x addresses, to flag poisoned lookalikes |
| text | string | yes | The untrusted text to screen (up to 16,384 characters) |
No output schema declared.
No examples provided.
token_facts Base token contract facts ~192
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.
| Name | Type | Req | Description |
|---|---|---|---|
| address | string | yes | The token contract's 0x address on Base |
No output schema declared.
No examples provided.
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.
remote · wren-presign-check.wrenonbase.workers.dev
claude mcp add --transport http claudeisgod-wren-presign-check 'https://wren-presign-check.wrenonbase.workers.dev/mcp'
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.