CorpusFetch
REMOTE · MCP.CORPUSFETCH.COM
O(1) symptom routing and warrant-first fetch over 622 concluded records.
Available components
Last scanned (8 hours ago)
Scores higher than 45% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Developer Tools
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 4 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 Usability73
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 354 tokens (~88/item across 4 items; 4 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management10
- Stability observed for 3 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
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
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
- Tool “corpusfetch_fetch_record” rewrote its description, which is the text the model reads security
- Tool “corpusfetch_fetch_warrant” rewrote its description, which is the text the model reads security
- Tool “corpusfetch_lookup_exception” rewrote its description, which is the text the model reads security
- Tool “corpusfetch_lookup_symptom” rewrote its description, which is the text the model reads security
- Server version: 1.0.1 → 1.0.2 functional
- 3 Nov 26 +1
- Stability: unverified → 0.03 ▲ functional
- 2 Nov 26 62
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://mcp.corpusfetch.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_256_GCM_SHA384 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=corpusfetch.com | CN=YR1,O=Let's Encrypt,C=US | 1 Nov 2026 | 30 Jan 2027 | RSA 2048 | SHA256-RSA | 6a0ede02192cf6207657c5b6ee71bff4ffe |
| SANs: corpusfetch.com, mcp.corpusfetch.com, www.corpusfetch.com | ||||||
| CN=YR1,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | a20253f15f2691c05dc1ce13b9bcca4e |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.corpusfetch.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| corpusfetch.com. | 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.corpusfetch.com/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.corpusfetch.com/mcp | HTTPS enforced | 301 | https://mcp.corpusfetch.com/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 →
corpusfetch_fetch_record ~84
Fetch the full resolved experience record. Format 'md' (~1500 tokens, includes reasoning) or 'py' (~300 tokens, zero-prose executable invariants).
| Name | Type | Req | Description |
|---|---|---|---|
| format | string|null | – | Format: "md" (default, ~1500 tokens) or "py" (~300 tokens) |
| slug | string | yes | Slug of the record |
No output schema declared.
No examples provided.
corpusfetch_fetch_warrant ~77
Fetch the compact ~220-token precondition seal for a resolved record. Always call this before fetching the full record. Check the seal; if it fails, the record does not apply to your current state.
| Name | Type | Req | Description |
|---|---|---|---|
| slug | string | yes | Slug of the record (the URL path segment after /c/ and before .md) |
No output schema declared.
No examples provided.
corpusfetch_lookup_exception ~75
Look up deterministic operational experience for a Python exception class (e.g., KeyError, TimeoutError). Use this when you encounter an unexpected runtime error and need an empirically verified boundary decision. Returns candidate addresses.
| Name | Type | Req | Description |
|---|---|---|---|
| exception_class | string | yes | Python exception class, e.g. KeyError, TimeoutError, ValueError |
No output schema declared.
No examples provided.
corpusfetch_lookup_symptom ~88
Look up operational experience for a specific runtime symptom (e.g., UNICODE_HOMOGLYPH_OR_MOJIBAKE). Use this when facing an ambiguous failure state or an unbounded reasoning loop. Returns candidate addresses.
| Name | Type | Req | Description |
|---|---|---|---|
| symptom | string | yes | Runtime symptom key, e.g. UNICODE_HOMOGLYPH_OR_MOJIBAKE, or a DOMAIN_* key |
No output schema declared.
No examples provided.
How do I install the CorpusFetch MCP server?
CorpusFetch is a hosted endpoint at https://mcp.corpusfetch.com/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.corpusfetch.com
claude mcp add --transport http com-corpusfetch-corpusfetch 'https://mcp.corpusfetch.com/mcp'
What is the CorpusFetch MCP server?
CorpusFetch is an MCP server listed in the public MCP registry as com.corpusfetch/corpusfetch. O(1) symptom routing and warrant-first fetch over 622 concluded records. This page covers its hosted endpoint (https://mcp.corpusfetch.com/mcp).
Is the CorpusFetch MCP server safe to use?
CorpusFetch scores 64 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 CorpusFetch MCP server expose?
CorpusFetch exposes 4 tools: corpusfetch_fetch_record, corpusfetch_fetch_warrant, corpusfetch_lookup_exception, corpusfetch_lookup_symptom. Their descriptions and schemas cost roughly 324 tokens of context every time the server is loaded.
Does the CorpusFetch MCP server require authentication?
No. We connected to CorpusFetch without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the CorpusFetch MCP server still maintained?
CorpusFetch 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.