agessaman
f4ba55be7a
waev's operator confirmed on 2026-08-11 that their servers do not disconnect a client when its JWT passes exp — a 60-minute token can hold a session open for hours. The renewal path assumed the opposite, in as many words: the comment at the bounce called the renewal buffer "the ONLY margin between 'device re-authenticates' and 'broker enforces exp and FIN-closes the session mid-stream' — observed on the waev preset". That premise made waev expensive, because waev is the only preset with a short token_lifetime (3300 s; every other is 0, meaning the 24 h default). It was therefore the only slot bouncing often: measured every ~47 minutes, about 30 times a day per device. And the bounce's re-handshake is where contiguous internal DRAM goes — one renewal traced on hardware took the largest free block from 27,124 to 16,372 B, below the 16,384 B mbedTLS inbound record buffer, after which that slot could not re-handshake at all. The teardown and the credential update cost nothing; the handshake costs everything. So for a broker that leaves live sessions alone, refresh the credentials in place and let the next genuine reconnect use them. That path already existed for the "token renewed but old one still valid" case; this just stops treating imminent expiry as a reason to tear down a healthy connection. mqttPresetEnforcesTokenExp() defaults to true and is keyed by preset name rather than a new struct field: adding a field would mean re-ordering a dozen positional initialisers, where a mistake is silent, and the wrong default costs an outage rather than a re-handshake. Custom and audience-only slots have no preset and are treated as enforcing. Our own logs already argued against the premise and we had not noticed: across 14 multi-device outages (10 hitting all four devices) the drops landed within ~3 s of each other, on devices whose independent boot times gave them independent token issue times. Independent expiries cannot align that tightly, so exp enforcement was never a good explanation for them. Unverified on hardware yet — the operator's statement is second-hand. Next: apply to one board only and confirm the session survives past exp, that a later reconnect still authenticates, and that the ~47-minute 27,124<->16,372 oscillation stops. (cherry picked from commit 27bd05a17b9303b158feec7dab60af2fe128f5ce)
About MeshCore
MeshCore is a lightweight, portable C++ library that enables multi-hop packet routing for embedded projects using LoRa and other packet radios. It is designed for developers who want to create resilient, decentralized communication networks that work without the internet.
🔍 What is MeshCore?
MeshCore now supports a range of LoRa devices, allowing for easy flashing without the need to compile firmware manually. Users can flash a pre-built binary using tools like Adafruit ESPTool and interact with the network through a serial console. MeshCore provides the ability to create wireless mesh networks, similar to Meshtastic and Reticulum but with a focus on lightweight multi-hop packet routing for embedded projects. Unlike Meshtastic, which is tailored for casual LoRa communication, or Reticulum, which offers advanced networking, MeshCore balances simplicity with scalability, making it ideal for custom embedded solutions, where devices (nodes) can communicate over long distances by relaying messages through intermediate nodes. This is especially useful in off-grid, emergency, or tactical situations where traditional communication infrastructure is unavailable.
MQTT Observer Setup — Prebuilt observer firmware, docs, and a changelog are at observer.gessaman.com. See the MQTT Implementation Guide for configuration, CLI commands, and troubleshooting.
⚡ Key Features
- Multi-Hop Packet Routing
- Devices can forward messages across multiple nodes, extending range beyond a single radio's reach.
- Supports up to a configurable number of hops to balance network efficiency and prevent excessive traffic.
- Nodes use fixed roles where "Companion" nodes are not repeating messages at all to prevent adverse routing paths from being used.
- Supports LoRa Radios – Works with Heltec, RAK Wireless, and other LoRa-based hardware.
- Decentralized & Resilient – No central server or internet required; the network is self-healing.
- Low Power Consumption – Ideal for battery-powered or solar-powered devices.
- Simple to Deploy – Pre-built example applications make it easy to get started.
🎯 What Can You Use MeshCore For?
- Off-Grid Communication: Stay connected even in remote areas.
- Emergency Response & Disaster Recovery: Set up instant networks where infrastructure is down.
- Outdoor Activities: Hiking, camping, and adventure racing communication.
- Tactical & Security Applications: Military, law enforcement, and private security use cases.
- IoT & Sensor Networks: Collect data from remote sensors and relay it back to a central location.
🚀 How to Get Started
- Watch the MeshCore QuickStart Playlist by The Comms Channel
- Watch the MeshCore Technical Presentation by Liam Cottle.
- Read through our Frequently Asked Questions and Documentation.
- Flash the MeshCore firmware on a supported device.
- Connect with a supported client.
For developers:
- Install PlatformIO in Visual Studio Code.
- Clone and open the MeshCore repository in Visual Studio Code.
- See the example applications you can modify and run:
- Companion Radio - For use with an external chat app, over BLE, USB or Wi-Fi.
- KISS Modem - Serial KISS protocol bridge for host applications. (protocol docs)
- Simple Repeater - Extends network coverage by relaying messages.
- Simple Room Server - A simple BBS server for shared Posts.
- Simple Secure Chat - Secure terminal based text communication between devices.
- Simple Sensor - Remote sensor node with telemetry and alerting.
The Simple Secure Chat example can be interacted with through the Serial Monitor in Visual Studio Code, or with a Serial USB Terminal on Android.
⚡️ MeshCore Flasher
We have prebuilt firmware ready to flash on supported devices.
- Launch https://meshcore.io/flasher
- Select a supported device
- Flash one of the firmware types:
- Companion, Repeater or Room Server
- Once flashing is complete, you can connect with one of the MeshCore clients below.
📱 MeshCore Clients
Companion Firmware
The companion firmware can be connected to via BLE, USB or Wi-Fi depending on the firmware type you flashed.
- Web: https://app.meshcore.nz
- Android: https://play.google.com/store/apps/details?id=com.liamcottle.meshcore.android
- iOS: https://apps.apple.com/us/app/meshcore/id6742354151?platform=iphone
- NodeJS: https://github.com/liamcottle/meshcore.js
- Python: https://github.com/fdlamotte/meshcore-cli
Repeater and Room Server Firmware
The repeater and room server firmware can be set up via USB in the web config tool.
They can also be managed via LoRa in the mobile app by using the Remote Management feature.
🛠 Hardware Compatibility
MeshCore is designed for devices listed in the MeshCore Flasher
📜 License
MeshCore is open-source software released under the MIT License. You are free to use, modify, and distribute it for personal and commercial projects.
Contributing
Please submit PR's using 'dev' as the base branch! For minor changes just submit your PR and we'll try to review it, but for anything more 'impactful' please open an Issue first and start a discussion. It is better to sound out what it is you want to achieve first, and try to come to a consensus on what the best approach is, especially when it impacts the structure or architecture of this codebase.
Here are some general principles you should try to adhere to:
- Keep it simple. Please, don't think like a high-level lang programmer. Think embedded, and keep code concise, without any unnecessary layers.
- No dynamic memory allocation, except during setup/begin functions.
- Use the same brace and indenting style that's in the core source modules. (A .clang-format is probably going to be added soon, but please do NOT retroactively re-format existing code. This just creates unnecessary diffs that make finding problems harder)
Help us prioritize! Please react with thumbs-up to issues/PRs you care about most. We look at reaction counts when planning work.
Running unit tests
To run unit tests, run the following command:
pio test --environment native --verbose
Road-Map / To-Do
There are a number of fairly major features in the pipeline, with no particular time-frames attached yet. In very rough chronological order:
- Companion radio: UI redesign
- Repeater + Room Server: add ACL's (like Sensor Node has)
- Standardise Bridge mode for repeaters
- Repeater/Bridge: Standardise the Transport Codes for zoning/filtering
- Core + Repeater: enhanced zero-hop neighbour discovery
- Core: round-trip manual path support
- Companion + Apps: support for multiple sub-meshes (and 'off-grid' client repeat mode)
- Core + Apps: support for LZW message compression
- Core: dynamic CR (Coding Rate) for weak vs strong hops
- Core: new framework for hosting multiple virtual nodes on one physical device
- V2 protocol spec: discussion and consensus around V2 packet protocol, including path hashes, new encryption specs, etc
📞 Get Support
- Report bugs and request features on the GitHub Issues page.
- Find additional guides and components on my site.
- Join MeshCore Discord to chat with the developers and get help from the community.