Currently only available for ESP32 based devices with external PSRAM. Requires the device to be set as a ROUTER or ROUTER_CLIENT.
**Don't enable Store & Forward Module on multiple nodes.**
:::
## Overview
:::caution
This is a work in progress and is partially available. Stability is not guaranteed.
:::
The Store & Forward Module is an implementation of a Store and Forward system to enable resilient messaging in the event that a client device is disconnected from the main network.
Because of the increased network traffic for this overhead, it's not advised to use this if you are duty cycle limited for your airtime usage (EU_868 and EU_433) nor is it advised to use this for presets using SF11 or SF12 (e.g. all of the LongRange and VeryLongRange presets).
- To use / test this you will want at least 3 devices
- One ESP32 device with PSRAM configured as a Meshtastic router.
- Two others will be regular clients. Nothing special required.
### Meshtastic channel configuration
Don't use this on the "LongRange" channel settings. You're welcome to try and report back, but those channels have a [low bitrate](/docs/overview/radio-settings#pre-defined).
Either use a custom channel configuration with at an at least 1kbit data rate or use a Medium or Short range preset.
### Router setup
:::warning
Don't enable the Store and Forward module on multiple nodes for now!
- Name your router node something that makes it easily identifiable, aka "Router".
- Configure the Store and Forward module
```shell title="Required - Enable the module"
meshtastic --set store_forward.enabled true
```
```shell title="Optional - Set maximum number of records to save to device"
meshtastic --set store_forward.records 100
```
:::tip
Best to leave `store_forward.records` at the default (`0`) where the module will use 2/3 of your device's available PSRAM. This is about 11,000 records.
:::
### Client Usage
Currently, no special configuration is required. To request your history sent to you, send the command into the message field "SF". That's it. This will eventually change to make it easier. At the moment, that message will be sent to everyone on the mesh but we'll (eventually) make it easier to use where there'll be a button (or maybe it'll be transparent) and the command isn't sent as a text message to the mesh.
| SF | Send the last hour worth of messages I may have missed |
The Store and Forward module will only service one client at a time. If a second client requests messages while the S&F is busy, the S&F will send a private message to the second client that they will need to wait.
The Store & Forward Router sends a periodic message onto the network. This allows connected devices to know that a router is in range and listening to received messages. A client like Android, iOS, or Web can (if supported) indicate to the user whether a store and forward router is available.
### History Return Max
Sets the maximum number of messages to return to a client device.
### History Return Window
Limits the time period (in minutes) a client device can request.
Set this to the maximum number of records to save. Best to leave this at the default (`0`) where the module will use 2/3 of your device's available PSRAM. This is about 11,000 records.
Because the device will reboot after each command is sent via CLI, it is recommended when setting multiple values in a config section that commands be chained together as one.