Incomplete JSON serialization for incoming Reactions (message: null, missing reaction object)

[sandman12345678]

The problem

When receiving a reaction (emoji) from an external contact via the /v1/receive endpoint in MODE=normal, the API returns a dataMessage envelope where message is null, but the expected reaction object (containing emoji, targetSentTimestamp, etc.) is entirely missing from the JSON output.

To Reproduce

Run the API in MODE=normal.

Send a text message from an external Signal account to the API number.

Call GET /v1/receive/+<number>.

While the poll is active, react to the message from the external account with an emoji (e.g., 👍).

Observe the JSON output.

Actual Behavior
The API returns a valid JSON structure for the event, but the dataMessage is empty except for the timestamp and null-message:
JSON

{
"envelope": {
"source": "+49123456789",
"sourceNumber": "+49123456789",
"timestamp": 1772140664347,
"dataMessage": {
"timestamp": 1772140664347,
"message": null,
"expiresInSeconds": 0,
"isExpirationUpdate": false,
"viewOnce": false
}
}
}

Expected Behavior
The dataMessage should contain a reaction object, similar to how the /v1/reactions POST endpoint structures its input:
JSON

"dataMessage": {
"timestamp": 1772140664347,
"message": null,
"reaction": {
"emoji": "👍",
"targetAuthor": "+49987654321",
"targetSentTimestamp": 1772140661000,
"isRemove": false
}
}

Context

Mode: normal (Native)

Version: [Deine Version, z.B. 0.7.x]

Note: Normal text messages are received correctly. Only reactions seem to lose their payload during JSON serialization.

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?

Normal Mode

What's the architecture of your host system?

x86-64

Additional information

No response

[bbernhard]

I think that is an upstream issue (could be related to this one: AsamK/signal-cli#1935)

[strichter]

This is related to: AsamK/signal-cli#1940

[strichter]

Best discussion is here: https://github.com/adstastic/nanoclaw/pull/15

[strichter]

Issue fixed here: AsamK/signal-cli#1944

[strichter]

Fix for the issue (x86 only): #799

[TWhidden]

Thanks! This will fix my mentions problem!

[strichter]

Alright, I fully tested everything on my systems and it works well. Note that I had to limit the JVM memory consumption to avoid crashing the system.

[strichter]

AsamK, the signal-cli maintainer, just informed me that the issue should be fixed on his master branch. I am testing that now.

[strichter]

Confirmed signal-cli master is working.

[strichter]

Two PRs address this issue:

• Fix Signal Desktop v8.0.0 binary ACI compatibility #799 — patches signal-cli v0.13.24 with null-safety guards for binary ACI fields (superseded)
• Fix Signal Desktop v8.0.0 binary ACI by building signal-cli from master #801 — builds signal-cli from master which already includes the fix upstream (preferred, smaller change)

[strichter]

@bbernhard It was not immediately obvious how to compile for non-x86 platforms.

[strichter]

Published at ghcr.io/strichter/signal-cli-rest-api:aci-fix

[strichter]

signal-cli master has a changed account format, so the above is not a drop in replacement.