> ## Documentation Index > Fetch the complete documentation index at: https://docs.wat.com/llms.txt > Use this file to discover all available pages before exploring further. # Error codes > Every error code the WAT Rooms API and the wat CLI can return, with the HTTP status and what to do next. The web app, the [`wat` CLI](/cli), and the [skills plugin](/plugin) all hit the same API, so they all surface the same errors. With `--json`, a CLI failure is always the envelope `{ "success": false, "error": { "code": "...", "message": "..." } }` plus the HTTP status. **Naming convention:** `lower_snake` codes come from the server (the API rejected the request). `UPPER_CASE` codes are synthesized by the CLI itself, before or instead of an API call. ## Booking validation and conflicts (server) | Code | HTTP | Meaning | What to do next | | ----------------- | ---- | ---------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | | `invalid_range` | 422 | The end time is not strictly after the start time, or a date failed to parse. | Fix the times: end must come after start, in a parseable format such as `2026-06-10T10:00`. | | `below_min` | 422 | The booking is shorter than the 15-minute minimum. | Lengthen the booking to at least 15 minutes. | | `in_past` | 400 | The booking starts in the past. | Pick a start time in the future. | | `beyond_horizon` | 400 | The booking starts more than 30 days ahead. | Pick a date within the 30-day [booking horizon](/booking-rules). | | `outside_hours` | 400 | The booking falls outside the opening hours (06:00 to 22:00 Europe/Brussels), or crosses midnight. | Move the booking inside opening hours, on a single Brussels day. | | `title_too_long` | 422 | The title exceeds 200 characters. | Shorten the title (it is optional, you can drop it). | | `invalid_guests` | 422 | A guest entry is not a valid email address (the message names it), or guests were passed on a maintenance block. | Fix or remove the flagged address and retry. | | `too_many_guests` | 422 | More than 10 guests on one booking. | Trim the guest list to 10 or fewer. | | `overlap` | 409 | The slot was taken between your availability check and the booking. | Re-check availability and pick another free slot. | | `budget` | 409 | The booking would push you past the 2-hour daily budget on some Brussels day. | Shorten the booking, move it to another day, or cancel one of your other bookings that day. | | `check` | 422 | The database's own constraints rejected the times (the backstop behind `invalid_range`). | Treat like `invalid_range`: fix the start and end times. | ## Authentication and permissions | HTTP | CLI code | Meaning | What to do next | | ---- | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 401 | `unauthenticated` | No API key, or the key is invalid or revoked. | Run `wat login`, or pass a valid key via `--api-key` / `WAT_CLI_API_KEY`. | | 403 | `permission-denied` | The key is valid but the action is not allowed: editing or cancelling someone else's booking, an admin-only action (maintenance blocks, `rooms list --all`), or no active member behind the key. | Stop and tell the user; only the booking's owner or an admin can do this. | | 401 | `INVALID_OTP` | The 6-digit login code is wrong or expired (`wat login`). | Request a fresh code with `--request-code` and retry. | | 403 | `NOT_AUTHORIZED` | Login completed the email code, but the email may not enroll: it is not on WAT's resident list (or the account is deactivated). | A resident-list miss automatically files an access request with the WAT admins. Tell the user to watch for the approval email, then log in again. Retrying does not speed up the review. | When the server returns an error without a code of its own, the CLI derives one from the HTTP status: `unauthenticated` (401), `permission-denied` (403), `not-found` (404), `conflict` (409), `validation` (422), `internal` (5xx), and `network-error` when no response arrived at all. ## CLI-side codes These never reach the server: the CLI fails fast locally and exits non-zero. | Code | Meaning | What to do next | | ---------------- | ------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ | | `ROOM_NOT_FOUND` | No active room matches the `--room` name or id. | Run `wat rooms list` and use an exact name or the room id. | | `AMBIGUOUS_ROOM` | More than one room shares that name. | Pass the room id instead of the name. | | `INVALID_TIME` | A `--start`, `--end`, `--from`, or `--to` value failed to parse. | Use an ISO-style value such as `2026-06-10T10:00`, optionally with `--tz` or an explicit offset. | | `MISSING_FLAG` | `wat login --json` needs a flag it did not get (it never prompts in JSON mode). | Pass the missing flag: `--email`, or `--code` after a `--request-code` send. |