Successful message sent to a group but signal-cli-rest-api respond with 400

[eugenyuk]

The problem

Hello @bbernhard,

I have an issue with sending a message to a group and receiving 400 response:

$ curl -s -X POST -H "Content-Type: application/json" -d '{"message": "MESSAGE", "number": "+123456789012", "recipients": ["group.1234567890="]}' 'http://127.0.0.1:8080/v2/send'
{"error":"Failed to send (some) messages:********/*******/**************/******/*****: Unregistered user \"********-****-****-****-************\"1780171156320"}

Despite of this, the message is delivered to a group but in the log the message is:

time="2026-06-05T22:29:15Z" level=debug msg="If you want to run this command manually, run the following steps on your host system:"
time="2026-06-05T22:29:15Z" level=debug msg="*) docker exec -it 8d041e01df1f /bin/bash"
time="2026-06-05T22:29:15Z" level=debug msg="*) su signal-api"
time="2026-06-05T22:29:15Z" level=debug msg="*) echo 'MESSAGE' | signal-cli-native --config /home/.local/share/signal-cli -a +1234567890123 send --message-from-stdin -g GROUP_ID"
time="2026-06-05T22:29:19Z" level=debug msg="signal-cli output (stdout): Failed to send (some) messages:\nID=: Unregistered user \"ID\"\n1780698557041\n"
time="2026-06-05T22:29:19Z" level=debug msg="signal-cli output (stderr): "
[GIN] 2026/06/05 - 22:29:19 | 400 |  3.490535311s |      10.0.2.100 | POST     "/v2/send"

Such a behaviour is relevant as for :latest tag as for current last available :1780010737-ci image tag.

Thank you.

Are you using the latest released version?

• Yes

Have you read the troubleshooting page?

• Yes

What type of installation are you running?

signal-cli-rest-api Docker Container

In which mode are you using the docker container?

Native Mode, Normal Mode

What's the architecture of your host system?

x86-64, aarch64

Additional information

No response

[eugenyuk]

Hello @bbernhard,

I've found the original signal-cli issue and I think signal-cli-rest-api should behave in similar way, isn't it? Currently, if at least one member of a group is unregistered, signal-cli-rest-api responds with 400. It behaves illogical as all members of a group, except unregistered one, still received a message. So the response should be successful 201, right?

Thank you.

[harrisondiamond]

I also encountered this issue recently.