Store and Forward

What Is Store and Forward?

Store and Forward (S&F) is a Meshtastic server module that buffers messages for nodes that are temporarily offline. When a client node comes back within range, the S&F server replays the messages the client missed while it was away.

How It Works

1. A node with S&F enabled in server mode listens to all channel 0 messages and stores them in a ring buffer in RAM.
2. When a client node configured in client mode reconnects to the mesh, it sends a replay request.
3. The server transmits buffered messages up to the configured History Return Max count and within the History Return Window time range.

Hardware Requirements

The server node needs sufficient RAM to maintain a useful message buffer:

• Recommended: T-Beam, Heltec V3, or any ESP32-S3 device with 4 MB+ PSRAM, or any nRF52840-based device (RAK4631, Nordic development kits).
• Avoid: Devices with very limited RAM (original ESP8266-based boards, small OLED nodes without PSRAM) — they may not maintain buffers of useful size.

Server Configuration

1. Navigate to Config → Module Config → Store and Forward.
2. Set Enabled → true.
3. Set Is Server → true.
4. Set History Return Max — the maximum number of messages to replay per request (default: 30).
5. Set History Return Window — the time window in minutes from which to replay messages.
6. Save and reboot the node.

Client Configuration

On each client device that should receive replays:

1. Config → Module Config → Store and Forward → Enabled → true.
2. Set role to Client (or Client Mute if the device should not rebroadcast).

The client will automatically request a replay from the nearest S&F server when it joins the mesh.

Ideal Use Cases

• Hikers or cyclists who move in and out of mesh coverage.
• Vehicles that periodically leave and re-enter a covered area.
• Remote monitoring stations that reconnect on a schedule.
• Emergency communication networks where message delivery must be ensured.

Limitations

• S&F only replays channel 0 messages by default in current firmware versions.
• Large message volumes on small-RAM devices will cause the ring buffer to overwrite older messages quickly.
• The server node must be continuously powered and on-mesh — a node that goes offline loses its buffer.
• S&F adds overhead to the server node; monitor channel utilisation on high-traffic networks.