signal-cli-to-file

Save incoming signal messages as files (for your note-taking system)

This script will parse all incoming messages (and attachments) and create files out of them in a specified location.

My use case is to write notes on my phone, take pictures or record audios that then just show up in my note-taking system. All very conveniently through signal.

What is the difference between the two scripts?

There are two ways to interact with signal-cli programmatically:

• signal-cli - full functionality, invoke when needed, structured text output
• signal-cli-rest-api - lacks some features, always running, JSON interface

The repo provides scripts for parsing either of them. (I am using the rest-api, since my local signal-cli broke.)

• script for signal-cli
• script for signal-cli-rest-api

About the scripts

They were created for my specific use case, so you might not like some of the opinions.

Principles & Quirks

• One message = one file
• Everything is written to one single "inbox" directory
• Errors are also written into that same directory (you can quickly see if something went wrong)
• In case of naming collision: append instead of overwrite
• Filenames past 60 characters are shortened
• A colon (:) in the first line of the message is meant to specify the file name
• If there an attachment comes with a message the message will be used for the file name
• Edits are discarded
• Single script file, no dependencies

While the scripts generally work, bugs or some misbehaviors are to be expected.

Intended usage

The script is intended to be run via cron (there is no output and errors written to files.) But nothing stands in the way always triggering them manually.

Setup

The script themselves require the phone number you want to use to be setup in the chosen provider.

And for you to configure some basic options in the script.

Setting up your number in signal-cli

Follow the instruction in the respective project:

• signal-cli
• signal-cli-rest-api

My quick notes for registering with a landline number (not meant to replace the above instructions):

# generate captcha: https://signalcaptchas.org/registration/generate
############### signal-cli setup
signal-cli -a $SIGNAL_NUMBER register --captcha CAPTCHA
sleep 60s
signal-cli -a $SIGNAL_NUMBER register --voice --captcha CAPTCHA
signal-cli -a $SIGNAL_NUMBER verify CODE
signal-cli -a $SIGNAL_NUMBER updateProfile  --given-name "My" --family-name "Bot" --about "Beep Boop, I'm automated" --avatar inbox.png

############### signal-api setup
# api ref: https://bbernhard.github.io/signal-cli-rest-api
curlj POST $API_HOST/v1/register/$SIGNAL_NUMBER '{use_voice: false, captcha: "CAPTCHA"}'
sleep 60s
curlj POST $API_HOST/v1/register/$SIGNAL_NUMBER '{use_voice: true, captcha: "CAPTCHA"}'
curlj POST $API_HOST/v1/register/$SIGNAL_NUMBER/verify/TOKEN
curlj PUT  $API_HOST/v1/profiles/$SIGNAL_NUMBER "{ name: 'My Bot', base64_avatar: '$(cat inbox.png | base64 -w0 -)' }"
curlj POST $API_HOST/v2/send "{number: '$SIGNAL_NUMBER', message: 'Hi from the API', recipients: ['YOUR_NUMBER']}"

• Captcha explanation
• curlj script

Configuring the scripts

The scripts themselves contain descriptions and examples for the individual options.

Tested scenarios

signal-api-to-inbox

I jotted down these cases while building and testing the script:

• Text: regular message
• Text: multi-line
• Text: url only
• Text: with colon to be used as title
• Attachment: image
• Attachment: multiple images
• Attachment: audio recording
• Attachment: pdf where the original file name is used
• Attachment: with a message to be used as the file name
• Edit