DRD Get User — Group 16, Code 141

Fetches one directory record by denomination + serial number. Open read: no authentication required. This is how a QMail client learns a correspondent’s display name, avatar symbols, inbox fee, and account age before sending.

Quick reference Request body Response Status codes Common mistakes

Quick reference

Command Group	16 (DRD)
Command Code	141 (`0x8D`)
Server function	`cmd_drd_get_user` in `cmd_drd.c`
Request body	Exactly 23 bytes: challenge(16) + DN(1) + SN(4) + terminator(2)
Authentication	None — user records are public
Success response	Status `250` + one user record (34 + name bytes)
Not found	Status `193` (`ERROR_NO_ENTRY`), no payload

Request body (23 bytes)

Body offset	Size	Field	Description
0–11	12	Challenge random	Random bytes generated by the client.
12–15	4	Challenge CRC32	Big-endian CRC32 of bytes 0–11.
16	1	Denomination	Denomination of the record being fetched.
17–20	4	Serial Number	Serial number of the record being fetched, big-endian.
21–22	2	Terminator	Fixed `3E 3E`. The body must be exactly 23 bytes.

Response

On success the payload is one user record in the standard DRD serialization:

User record payload (34 + FL + LL bytes)

+------+--------+-----------+----+----+----+------------+------------+----+-------+----+------+
| DN   | SN     | inbox fee | S1 | S2 | CR | created_at | updated_at | FL | first | LL | last |
| 1    | 4 (BE) | 8 (BE)    | 1  | 1  | 1  | 8 (BE)     | 8 (BE)     | 1  | FL    | 1  | LL   |
+------+--------+-----------+----+----+----+------------+------------+----+-------+----+------+
offset 0   1       5          13   14   15   16           24           32   33     ...  ...

Payload offset	Size	Field	Description
0	1	Denomination	Echo of the record key.
1–4	4	Serial Number	Echo of the record key, big-endian.
5–12	8	Inbox fee	Big-endian signed int64, units of 10⁻⁸ CC.
13	1	First symbol	Avatar symbol index.
14	1	Second symbol	Avatar symbol index.
15	1	Class rejection (CR)	Signed minimum sender denomination (`0x00` = accepts all; `0xFF` = −1 = 0.1 CC). Senders below this denomination are rejected at the Tell gate with `ERROR_SENDER_CLASS_REJECTED` (237).
16–23	8	created_at	Big-endian Unix seconds. First-post time; never changes. Display account age from this.
24–31	8	updated_at	Big-endian Unix seconds of the latest post.
32	1	First-name length (FL)	0–63.
33...	FL	First name	UTF-8.
33+FL	1	Last-name length (LL)	0–63.
34+FL...	LL	Last name	UTF-8.

Status codes

Decimal	Hex	Symbol	Meaning
250	0xFA	`STATUS_SUCCESS`	Record returned in the payload.
193	0xC1	`ERROR_NO_ENTRY`	No record exists for that denomination/serial on this RAIDA.
16	0x10	`ERROR_INVALID_PACKET_LENGTH`	Body is not exactly 23 bytes.
252	0xFC	`ERROR_INTERNAL`	Database failure.
254	0xFE	`ERROR_MEMORY_ALLOC`	Server allocation failure.

Common mistakes

Treating 193 on one RAIDA as “user does not exist”

RAIDAs are independent. A record can be present on 24 servers and missing on one that was offline during the post. Query a few servers before concluding a user is unregistered.

Reading names as fixed-width fields

Both names are length-prefixed and variable. The record has no fixed total size; always honor FL and LL.