Fetter MCP
REMOTE · MCP.FETTER.IO · SCANNED SEP 20
Real-time Python package and vulnerability data for AI coding agents.
Available components
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 Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 3 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- 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 Usability69
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 341 tokens (~113/item across 3 items; 3 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
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 3 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities40
- Spec-recency check failed: implements MCP spec 2025-03-26; the latest is 2026-07-28. See how to fix → Fail
How do I install the Fetter MCP server?
Fetter MCP is a hosted endpoint at https://mcp.fetter.io/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 · mcp.fetter.io
claude mcp add --transport http fetter-io-fetter-mcp 'https://mcp.fetter.io/mcp'
{
"mcpServers": {
"fetter-io-fetter-mcp": {
"url": "https://mcp.fetter.io/mcp"
}
}
} {
"servers": {
"fetter-io-fetter-mcp": {
"type": "http",
"url": "https://mcp.fetter.io/mcp"
}
}
} [mcp_servers.fetter-io-fetter-mcp] url = "https://mcp.fetter.io/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"fetter-io-fetter-mcp": {
"type": "remote",
"url": "https://mcp.fetter.io/mcp",
"enabled": true
}
}
} openclaw mcp add fetter-io-fetter-mcp --url 'https://mcp.fetter.io/mcp' --transport streamable-http
mcp_servers:
fetter-io-fetter-mcp:
url: "https://mcp.fetter.io/mcp" {
"McpServers": {
"fetter-io-fetter-mcp": {
"Transport": "http",
"Url": "https://mcp.fetter.io/mcp"
}
}
} assistant mcp add fetter-io-fetter-mcp -t streamable-http -u 'https://mcp.fetter.io/mcp'
{
"mcpServers": {
"fetter-io-fetter-mcp": {
"type": "http",
"url": "https://mcp.fetter.io/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
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.
- 26 Aug 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 +1
- Stability: 0.97 → pass security
- 23 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 10 Aug 26 0
- Schema quality: good → excellent functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 0
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 20 Sept 2026 · Probed https://mcp.fetter.io/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mcp.fetter.io | CN=Amazon RSA 2048 M01,O=Amazon,C=US | 26 Jul 2026 | 8 Feb 2027 | RSA 2048 | SHA256-RSA | 87b62283998d681a809e306e722e57d |
| SANs: mcp.fetter.io, www.mcp.fetter.io | ||||||
| CN=Amazon RSA 2048 M01,O=Amazon,C=US (CA) | CN=Amazon Root CA 1,O=Amazon,C=US | 23 Aug 2022 | 23 Aug 2030 | RSA 2048 | SHA256-RSA | 77312380b9d6688a33b1ed9bf9ccda68e0e0f |
| CN=Amazon Root CA 1,O=Amazon,C=US (CA) | CN=Starfield Services Root Certificate Authority - G2,O=Starfield Technologies\, Inc.,L=Scottsdale,ST=Arizona,C=US | 25 May 2015 | 31 Dec 2037 | RSA 2048 | SHA256-RSA | 67f944a2a27cdf3fac2ae2b01f908eeb9c4c6 |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.fetter.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 57355 | 8 | Verified |
| fetter.io. | absent | 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 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.fetter.io/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.fetter.io/mcp | HTTPS enforced | 301 | https://mcp.fetter.io/mcp |
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 →
is_vulnerable ~73
Check if a specific package version has known vulnerabilities. Requires an exact version specifier (e.g., 'requests==2.31.0').
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | The exact package name and version (e.g., "requests==2.31.0", "numpy==1.24.0"). |
No output schema declared.
No examples provided.
lookup ~208
Look up a package by name and (optionally) version number to find which versions are available and/or have vulnerabilities.
| Name | Type | Req | Description |
|---|---|---|---|
| cvss_filter | string | – | CVSS score filter: "all" to show all vulnerabilities, "max" to show only the maximum observed score, or a number (0.0-10.0) to filter by threshold |
| limit | integer | – | When the name is not an exact version, limit the number of recent versions to check. |
| name | string | yes | The package name to look up (e.g., "requests", "numpy>=2.0", "flask==3.0.0"). Note that when an exact "==" version is specified, the `limit` and `retain_passing` parameters have no effect. |
| retain_passing | boolean | – | 'When the name is not an exact version, setting this to True will return refernces for all packages, include those with no vulnerabilities (default: false) |
No output schema declared.
No examples provided.
most_recent_not_vulnerable ~52
Find the most recent version of a package that has no known vulnerabilities.
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | The package name to look up (e.g., "requests", "numpy", "flask"). |
No output schema declared.
No examples provided.
What is the Fetter MCP server?
Fetter MCP is listed in the public MCP registry as io.github.fetter-io/fetter-mcp. Real-time Python package and vulnerability data for AI coding agents. This page covers its hosted endpoint (https://mcp.fetter.io/mcp).
Is the Fetter MCP server safe to use?
Fetter MCP scores 75 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 Fetter MCP server expose?
Fetter MCP exposes 3 tools: lookup, most_recent_not_vulnerable, is_vulnerable. Their descriptions and schemas cost roughly 333 tokens of context every time the server is loaded.
Does the Fetter MCP server require authentication?
No. We connected to Fetter MCP without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Fetter MCP server still maintained?
Fetter MCP is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.