Find an existing signed verdict before you install or pay to scan (free, no API key)
find_attestationCheck whether an artifact (npm package, MCP server URL, or sha256 hash) already has a signed attestation before installing or scanning it. Returns the verdict, freshness, and contradictions.
Instructions
Asks whether anyone has already attested an artifact, BEFORE you install it or pay to scan it. Give a package identity like "chalk@5.6.1", an MCP server endpoint URL, or a sha256 content hash. Returns the signed verdict if one exists, plus freshness: whether the known-bad corpus has since contradicted it and whether it was attested under an older rules version.
WHEN TO USE: as the first question about one specific artifact, since it is free and instant. Use verify_attestation instead when someone already handed you an attestation token. Use scan_artifact (or scan_lockfile_deep for a whole tree) when nothing has been attested yet, or when the verdict found here is stale.
COST AND EFFECTS: free, no API key, no payment. Read-only, a single HTTPS lookup.
LIMITS: a miss means no attestation is on record for this subject; it is not a verdict either way. An attestation carries the verdict, never the evidence, and it describes the artifact at the time it was made. An MCP server can change what it advertises with no new version, so for a server the result says how to confirm the verdict still applies.
WHEN NOBODY HAS ATTESTED IT: if the subject is an npm package identity, the answer falls back
to a free identity check against published advisories, returned as answer: "identity_check"
with an identity_check object. found stays false, because an identity check is NOT an
attestation: it is unsigned, it looks at the package identity rather than its code, and absence
from the advisory corpus is not a verdict on the artifact.
READING THE RESULT: check contradicted first: non-null means the subject is NOW a known-bad
match, so a stored clear must not be trusted (this result is then marked as an error).
identity_check.listed_as_malware: true means this exact version is published as malware, and
that result is marked as an error too, so it cannot be summarised as "no attestation found".
identity_check.listed_as_malware: null means the corpus could not be consulted: unchecked,
never clear. found: false is not a clean verdict. stale_rules: true means it was attested
under an older rules version, so re-scan for a current verdict. attestation is a compact JWS
you can verify with verify_attestation or offline against https://lazaretto.dev/.well-known/jwks.json.
Tool call template
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"subject": "<subject>"
},
"name": "find_attestation"
}
}Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| subject | Yes | What to look up: a package identity such as "chalk@5.6.1" (pin an exact version), an MCP server endpoint URL such as "https://example.com/mcp", or a sha256 content hash as 64 hex characters, with or without a leading "sha256:" prefix. |