Channel (Meshtastic)

Channel (Meshtastic) is a named, encrypted logical group that determines which nodes can read and relay a given message on a Meshtastic mesh. Each device supports up to eight channels — one Primary and up to seven Secondary — all sharing the same physical LoRa radio and frequency slot, but each protected by its own pre-shared key (PSK). Channels are how a single mesh can carry private group conversations alongside public traffic without giving every node access to everything: the radio layer is shared, the readability is not.

Primary vs. secondary

Exactly one Primary channel exists per device and cannot be disabled; periodic broadcasts such as position and telemetry go out exclusively over it. The Primary defaults to the well-known key "AQ==", which is effectively public — anyone with stock settings can hear it, which is precisely what makes out-of-the-box Meshtastic devices interoperate. Secondary channels are where privacy lives: you set a custom name and PSK to create a closed group. Meshtastic uses AES-256 (32-byte key) or AES-128 (16-byte key); a 0-byte key disables encryption entirely, which is occasionally useful for open community channels but should never carry anything you care about. A node that lacks a channel's key can still relay its packets — encrypted traffic is forwarded blind — so private groups still benefit from the whole mesh's coverage without exposing content to it.

Setting up a private group

To form a closed group, all members import the same channel name and PSK, most easily via the QR code or share URL the Meshtastic app generates. The practical discipline matters more than the cryptography:

• Generate a random PSK rather than typing a guessable phrase, and share the QR code in person or over an already-secure channel — the key distribution is the weak point, not AES.
• Name channels descriptively but not revealingly; channel names travel with the configuration you share.
• Rotate the PSK if a device is lost or a member leaves — there is no per-member revocation, because everyone in a channel holds the same secret.

Remember also that channel membership controls confidentiality, while the hop limit controls reach; the two are configured independently, and a private channel still obeys the same hop budget as everything else.

One configuration subtlety trips up new meshes: channels are an encryption-and-membership layer, but radio compatibility is set separately by the modem preset, frequency region, and slot. Two nodes with identical channel QR codes still cannot talk if their LoRa settings differ, and two nodes with matching radio settings but different PSKs will relay each other's traffic without ever reading it. When a new node "can't see" the group, check the radio layer first and the channel layer second.

Why it matters for sovereignty

Channels turn an open LoRa mesh into something usable for a family, a homestead, a mining crew, or a neighbourhood watch without everyone sharing one transparent broadcast. A crew channel for site coordination, a family channel for check-ins, and the public Primary for mesh-wide reach can coexist on the same hardware — infrastructure-free group communications with no SIM card, no server, and no account. The limits are worth knowing plainly: a shared PSK is group encryption, not per-person identity; metadata such as node IDs and traffic timing remains observable to anyone in radio range; and physical access to a member device means access to the channel. For internet-backed end-to-end privacy with no shared secret to distribute, compare app-layer messengers like SimpleX Chat — and treat Meshtastic channels as what they are: a remarkably capable local layer you fully own.

Full open-data reference: Meshtastic LoRa Modem Presets — CSV / JSON + REST API, CC BY 4.0.