Added homekit-decode.sh to the mix, and updated the readmes.

README.md

@@ -9,6 +9,11 @@ is inside.
 No build, no install, no package step. Two ways to use it: a browser app and a
 command-line script that share the same decode logic.
 
+There is also a separate, standalone command-line decoder for Apple **HomeKit**
+setup codes — the `X-HM://` payload an accessory shows on first setup. That is a
+different format from Matter's `MT:` (see [HomeKit setup-code decoder](#homekit-setup-code-decoder));
+it has no browser counterpart and no companion tables.
+
 ## What it decodes
 
 Given an `MT:` URI, the payload (84 bits, see [Data format](#data-format)) is
@@ -31,6 +36,7 @@ split into these fields:
 |---|---|
 | [`matter-qr-decoder.html`](matter-qr-decoder.html) | The browser app. Single self-contained HTML file (Vue 3 + Bootstrap 5.3, loaded from CDNs). |
 | [`matter-decode.sh`](matter-decode.sh) | A pure-bash CLI port of the same decode logic. No camera scanning. |
+| [`homekit-decode.sh`](homekit-decode.sh) | A standalone pure-bash decoder for Apple **HomeKit** setup codes (the `X-HM://` payload) — a different format from Matter's `MT:`, with no browser counterpart and no companion tables. |
 | [`manufacturers.tsv`](manufacturers.tsv) | Tab-separated `vendor ID → name` table (~900 rows) used to turn a numeric vendor ID into a name. Shared by both tools; optional. |
 | [`gen-manufacturers.py`](gen-manufacturers.py) | Python 3 script that regenerates `manufacturers.tsv`; pulls the upstream `manufacturers.xml` over the network by default (or a URL/local file/HTML block you pass in). |
 | [`products.tsv`](products.tsv) | Tab-separated `vendor ID → product ID → name` table (3 columns) used by `matter-decode.sh` to turn a product ID into a name, for any vendor that has a catalog (e.g. **LIFX**, vendor `0x1306` / `4870`). Optional. |
@@ -227,9 +233,72 @@ product name and vice-versa.
 The table is hand-edited and optional: a missing file simply means no equivalent
 is considered. The canonical (col-2) id should not itself appear in col-1.
 
+## HomeKit setup-code decoder
+
+`homekit-decode.sh` decodes a **HomeKit** setup code — the `X-HM://` payload an
+Apple accessory (or its packaging) shows on first setup. It is a *different*
+on-wire format from Matter's `MT:`, a standalone tool with no browser app and no
+companion tables — the accessory-category names are inlined in the script.
+
+```sh
+./homekit-decode.sh                  # defaults to the demo payload 005KEOUCE
+./homekit-decode.sh "X-HM://005KEOUCE"
+```
+
+A leading `X-HM://` is stripped if present; the first 9 characters are the fixed
+parameter block and anything after them is a variable-length **setup id**, kept
+verbatim (it is not part of the numeric block).
+
+Example output:
+
+```
+$ ./homekit-decode.sh
+Setup PIN: 38313374
+Flag: 10
+  Supports NFC: False
+  Supports IP: True
+  Supports BLE: False
+  Supports WAC/MFi: True
+Category ID: 5 (Lightbulb)
+Reserved: 0
+Version: 0
+Setup ID: <none>
+Setup Payload: X-HM://005KEOUCE
+```
+
+### How it decodes
+
+Unlike Matter's **base38** payload (`0-9 A-Z - .`), the 9-character HomeKit block
+is **base36** (`0-9 A-Z`, 36 symbols) — an out-of-range character is a hard
+error. The resulting integer is sliced **least-significant-bit first** into the
+HomeKit field layout:
+
+```
+pin(27) | flag(4) | categoryId(8) | reserved(4) | version(3)
+```
+
+- **Flag** is a 4-bit sub-flag set: `1` = NFC, `2` = IP, `4` = BLE, `8` = WAC/MFi
+  (each printed True/False).
+- **Category ID** is resolved to its HomeKit
+  [`homekit_accessory_category`](https://developer.apple.com/documentation/homekit/hmaccessorycategory)
+  name (e.g. `5` → Lightbulb, `8` → Switch); an id not in the table prints
+  "unknown".
+- The fields are packed back into a 9-character block and printed as a
+  reconstructed `X-HM://…` payload, so the output is a complete record the barcode
+  can be rebuilt from.
+
+The script uses the **corrected** bit layout that `composeSetupUri` in the
+`homekit-code` package actually encodes; an earlier version had the
+`categoryId` / `flag` / `version` positions misaligned. Each fix is noted in the
+script's header comments.
+
+---
+
 ## License
 
 The vendor mapping is derived from Matter/CHIP's `manufacturers.xml`, which is
 Apache-2.0. The LIFX product mapping is derived from LIFX's `products.json`.
-Vendor equivalences (`vendor-equivalents.tsv`) are maintained locally. The app
+Vendor equivalences (`vendor-equivalents.tsv`) are maintained locally. The
+HomeKit decoder's accessory-category names follow Apple's HomeKit
+`homekit_accessory_category` definitions. The app
 itself is a small single-file utility.