The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the SecOps Field Notes listing page.
The things a security analyst does by hand a dozen times a shift, as tools your coding agent can call: score a CVE, pull the indicators out of a report and defang them for the ticket, read a phishing email's headers properly, work out what kind of hash that is, decode a JWT, turn a timestamp into something a human can read, peel a base64-of-hex payload, and check whether a CVE is on CISA's exploited-in-the-wild list.
Free, MIT, no account, no telemetry. Everything except the KEV lookup runs entirely on your machine.
Pin the version.
Claude Code
Claude Desktop, Cursor, or any client with a JSON config
Docker
Node 18 or newer for the npx route. Also in the official MCP registry as
io.github.labaccessnow/secops-field-notes-mcp.
| Tool | What it answers | Network |
|---|---|---|
cvss_score | CVSS 3.1 base score from a vector or the eight metrics, exactly as FIRST computes it | none |
extract_iocs | Every IP, domain, URL, email, CVE id and hash in a blob of text — refanged on the way in, defanged on the way out | none |
defang_text | hxxp[://], [.], [at] and back | none |
analyze_email_headers | The Received chain in order with hop delays, the origin IP, SPF/DKIM/DMARC, and the mismatches phishing triage looks for | none |
identify_hash | bcrypt, Argon2, yescrypt, Unix crypt, LM:NT, MD5/NTLM, SHA-1/224/256/384/512 — by shape, with what that implies | none |
decode_jwt | Header, payload, times as dates; flags alg:none, expiry, tokens that never expire | none |
convert_timestamp | Epoch s/ms/µs, Windows FILETIME, ISO 8601, RFC 2822 — into every form | none |
decode_layers | Chain base64 / hex / URL / HTML-entity / ROT13 decoding and see each layer | none |
lookup_kev | Is this CVE exploited in the wild — CISA KEV date added, due date, ransomware use, required action | CISA feed, cached 1h |
latest_field_note | What got exploited this week | RSS |
Paste the raw source. It unfolds the headers, reads the Received lines in chronological order
(they are stored newest-first), computes the delay at each hop, finds the first public IP in the
chain, reads the authentication verdicts, and then says what a triage analyst would say:
The arithmetic is the FIRST specification's, including the Roundup function done in integer
arithmetic so floating-point noise never pushes a 4.0 to a 4.1. Log4Shell's vector scores 10.0;
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H scores 9.8. Both are in the test suite.
lookup_kev fetches CISA's public catalog (about 1.7 MB) and keeps
it for an hour. Everything else never opens a socket.MIT. Written by James Son — network, security, and automation engineer. The logic is the same as the free Field Kit desktop app's security tools, so the two stay in step. Corrections welcome.