BLE Local Mesh

EdgeCoder agents on nearby devices form a Bluetooth Low Energy mesh when internet connectivity drops. This allows task routing, credit tracking, and model discovery to continue offline.

How It Works

When an agent fails 3 consecutive heartbeats (45 seconds), it enters offline mode:

1. BLE scanning activates — discovers nearby EdgeCoder devices
2. Each device advertises capabilities via BLE GATT characteristics
3. The cost-based router selects the best peer for each task
4. Credit transactions are recorded in an offline ledger
5. When connectivity returns, the offline ledger syncs to the coordinator

BLE GATT Service Profile

EdgeCoder uses a custom BLE service with these characteristics:

Characteristic	UUID Suffix	Purpose
Peer Identity	0002	Agent ID, mesh token hash
Capabilities	0003	Model, param size, memory, battery, load, device type
Task Request	0004	Chunked task payload (prompt, language, context)
Task Response	0005	Chunked result (generated code, output, CPU seconds)
Ledger Sync	0006	Credit transaction batch

Service UUID: E0D6EC00-0001-4C3A-9B5E-00ED6EC0DE00

Payloads exceeding the 512-byte MTU are chunked with a 4-byte header (2-byte sequence number + 2-byte total count, big-endian).

Cost-Based Routing

The router scores each peer and selects the lowest-cost option:

cost = modelPreferencePenalty + loadPenalty + batteryPenalty + signalPenalty

Factor	Formula	Notes
Model preference	max(0, (7 - paramSize) * 8)	Larger models preferred, never rejected
Load	currentLoad * 20	Busy peers cost more
Battery (phones)	(100 - batteryPct) * 0.5	Low-battery phones deprioritized
Signal	min(30, max(0, (-RSSI - 30) * 0.5))	Weak signal penalized

Peers with cost >= 200 are skipped. Stale peers (>60s since last seen) are evicted.

Model Quality Multiplier

Credit earnings scale with model capability:

Model Size	Multiplier
7B+	1.0x
3B-7B	0.7x
1.5B-3B	0.5x
< 1.5B	0.3x

Offline Credit Ledger

Every completed task generates a dual-signed credit transaction:

• Requester signs before sending the task
• Provider counter-signs after returning results
• Transaction includes: task hash, CPU seconds, credit amount, timestamps

Transactions persist to device storage (UserDefaults on iOS, in-memory on Node.js).

Batch Sync

When connectivity returns, the agent sends all pending transactions to POST /credits/ble-sync. The coordinator deduplicates by txId and records them in the ordering chain.

Integration Points

• iOS: BLEMeshManager.swift uses CoreBluetooth (CBCentralManager + CBPeripheralManager)
• Node.js: ble-mesh-manager.ts uses @abandonware/noble (scanning) and @abandonware/bleno (advertising)
• Coordinator: POST /credits/ble-sync ingests offline transactions