v0.3.0

Changed

• An MCP tool call carrying an argument the tool does not declare now fails
  instead of being quietly ignored. This is a deliberate behaviour change,
  required by org ADR-021 §4. Until now a misspelt argument was dropped and the
  call ran without it, which was worst on search_vendor: send offest
  instead of offset and every page of a broad registrant search comes back as
  the first 50 matches, so a loop that walks has_more repeats page one forever
  and never sees the rest. Every tool — including get_usage, update_db and
  db_status, which take no arguments — now decodes with
  DisallowUnknownFields and refuses the call, naming the offending field:
  arguments: json: unknown field "offest".

  A malformed argument object is refused for the same reason. The decode error
  used to be discarded along with the unknown field, so {"macs": "286FB9…"} —
  one address where an array was expected — ran as if no address had been
  supplied and came back with "provide 'mac' … or 'macs'", an answer that
  contradicted the request. It now reports the type mismatch.

  Nothing runs before the arguments decode, so a rejected call reads no
  registry and downloads nothing. Omitting arguments, or sending {} or
  null, still means "no arguments" and is not an error. There is no
  compatibility shim: an argument name this server does not declare has never
  meant anything, so the only fix is to correct it.

Fixed

• Every MCP tool input schema is closed. The schemas omitted
  additionalProperties: false, so a mistyped argument read as a legitimate one
  to any client that validates against them. Schemas are now built through a
  single obj() helper that sets the flag, and an arch test fails if a tool's
  schema omits it — org ADR-021 §10 requires the test as well as the flag,
  because a rule stated only in prose is re-decided by whoever adds the next
  tool.

v0.2.1

Fixed

• A number in the config file was accepted when it was not one. NaN passed the
  range check — it fails every comparison, so "reject what is below the floor"
  lets it through — and Inf or 1e300 overflowed the duration it became.
  Ranges are now stated from the inside, with a ceiling.

v0.2.0

Changed

• search_vendor returns its matches inline. The MCP tool no longer writes
  a JSON Lines file: matches come back in matches, bounded by limit
  (default 50, was "no limit") and walked with the new offset, with has_more
  saying whether any are left. total is still the true count.

  Migration: replace a workspace_root call plus a file read with a loop that
  advances offset by limit while has_more is true.

Added

• search_vendor takes offset, and every result carries offset, limit and
  has_more.

Removed

• search_vendor's workspace_root argument and the matches_file /
  written / truncated / note / format result fields.
• The [workspace] config section and MAC_LOOKUP_WORKSPACE. The server has no
  output directory: it touches no filesystem, so it works unchanged against a
  client that has none.

mac-lookup v0.1.0

First release.

Resolve a MAC address or BSSID to its manufacturer — and, before that, to what kind of address it actually is. Offline, from a locally cached copy of the IEEE Registration Authority registries. CLI and local MCP server.

Why it is not just an OUI table

• A randomized MAC has no manufacturer. Phones rotate a locally administered address per network; virtual NICs and containers do the same. Reported as locally administered — vendor lookup does not apply, not as "vendor unknown".
• The first six digits are not enough. IEEE subdivides 24-bit blocks into 28-bit (MA-M) and 36-bit (MA-S/IAB) assignments, so several vendors share one OUI. Matching is longest-prefix-first.
• Some blocks belong to IEEE itself. ~429 MA-L rows are registered to "IEEE Registration Authority" — blocks held for subdivision, reported as OUI subdivided, never as a vendor.

Included

• lookup / search / update / status / mcp
• Grep-style exit codes for a single address; batch mode for many, stdin, or --json
• MCP tools: lookup_mac, search_vendor (file-mediated), db_status, update_db, get_usage
• Conditional downloads (ETag / Last-Modified); "unchanged upstream" and "IEEE unreachable" are reported distinctly
• No credentials — the IEEE registries are public
• Zero external dependencies (Go standard library only)

Install

brew install nlink-jp/tap/mac-lookup

The darwin/arm64 build is Developer ID signed and Apple-notarized.