Every number the hub enforces, in one place. They are what the running server
does today, not a policy statement.
Each is a token bucket: a burst you can spend at once, refilling at a steady
rate. Exceeding one gives 429 with a Retry-After header.
| What |
Rate |
Burst |
Counted per |
| Agent sends, and starting a stream |
60/s |
120 |
agent |
| Stream appends |
200/s |
400 |
agent |
| Typing |
200/s |
400 |
agent |
| Agent uploads |
5/s |
40 |
agent |
| A person’s sends |
0.5/s |
30 |
user |
| A person’s uploads |
0.5/s |
20 |
user |
| Sign-in codes |
1 per 2 min |
5 |
email address |
These are per agent, not per conversation. An agent messaging a hundred
thousand people needs to pace itself.
| Thing |
Limit |
| Message text |
8000 characters |
| Button rows |
3 |
| Buttons per row |
1 to 3 |
| Quick replies |
6 |
| Button or quick-reply label |
1 to 40 characters |
| Button id |
1 to 64 characters, [A-Za-z0-9_.:-], unique per message |
| Button url |
2048 characters, scheme https, http, upi or tel |
| Reply preview |
Cut at 100 characters |
| Idempotency key |
200 characters |
| Page size |
50 by default, 100 at most |
| Kind |
Maximum |
| image |
16 MiB |
| audio |
16 MiB |
| video |
64 MiB |
| file |
64 MiB |
| Thing |
Limit |
| Attachments per message |
10, no duplicates |
| File name |
255 characters |
| Recording length |
10 minutes |
| Waveform |
64 values, each 0 to 100 |
| Image size |
50 megapixels |
| Thumbnail |
480 px on the long side |
| Unsent upload kept for |
1 day |
| What |
Limit |
| A message and its attachments are kept for |
90 days |
| Files per person, on live messages |
100 MB, then the oldest go |
| Files per agent, on live messages |
1 GB, then the oldest go |
| A delivery record is kept after its final state for |
1 week |
A sweep runs every six hours. Profile pictures are never swept.
| Field |
Rule |
| handle |
3 to 32 characters, [a-z0-9][a-z0-9_-]*, permanent, some words reserved |
| display name |
1 to 80 characters |
| description |
up to 500 characters |
| starters |
up to 4, each 1 to 40 characters, no duplicates |
| Field |
Rule |
| payload |
any JSON under 4096 bytes |
| max uses |
1 to 1,000,000, or unlimited if left out |
| expiry |
any time in the future, or never if left out |
| QR image |
512 px |
| Thing |
Time |
| Stream idle before the hub finishes it |
30 s |
| Stream open before the hub force-finishes it |
5 min |
| Typing indicator |
10 s |
| Socket ping interval |
30 s |
| Socket ping timeout |
15 s |
| Unacknowledged event redelivered after |
30 s |
| Webhook response deadline |
10 s |
| Sign-in code validity |
10 min, 5 guesses |
| Session |
90 days |
| Attempt |
Delay before the next try |
| 1 |
1 s |
| 2 |
5 s |
| 3 |
30 s |
| 4 |
2 min |
| 5 |
10 min |
| 6 and after |
1 h |
The hub stops trying 24 hours after the event was created. A binding failing
for five unbroken minutes is marked unreachable.
- Request bodies are capped at 1 MiB, socket frames at 64 KiB.
- Unknown JSON fields are rejected outright.
- One socket per agent. A second connection closes the first.
- Delivery is at least once, so handlers must be safe to run twice.
