Clarification on message-rate limits and CAPTCHA thresholds in signal-cli v0.13.6

[rpolor]

Environment

• signal-cli version: 0.13.6
• JVM version: OpenJDK 21.0.2 (2024-01-16)
• OS & version: Debian 12 (Bookworm)

Usage scenario Sending batches of plain-text notifications to individual numbers, including commands that target multiple recipients in one invocation.

Observed behavior

• When sending to just 3 numbers at once (e.g. signal-cli send -m "Hello" +123… +456… +789…), I immediately hit a CAPTCHA and must solve it before proceeding.

Questions

1. What’s the exact maximum number of messages allowed in a rolling 60 s window before a CAPTCHA is enforced?
2. Are rate thresholds different for 1:1 or multiple recipients in one invocation?
3. If the limit is exceeded, what’s the default cooldown period before sends resume without CAPTCHA?
4. Is there a programmatic way to query current rate-limit status (remaining “quota”) before submitting a batch?

[madrid-fran]

Hi,

I'm having the same issue with the CAPTCHA when sending the same message to multiple devices.

I'd like to continue using SIGNAL and not have to resort to other sending platforms.

Like @rpolor

• What’s the exact maximum number of messages allowed before a CAPTCHA is enforced?

• If the limit is exceeded, what’s the default cooldown period before sends resume without CAPTCHA?