> **Build Small Hackathon entry** β Backyard AI track Β· π Tiny Titan Β· π€ Best Agent π«₯ press e or a to see the easter egg.
>
> πΊ **Demo video:** HF Space Recording Β· Simple Show Demo
> π£ **Social post:** [tweet on x](https://twitter.com/zX14_7/status/2064853015622775047) [tweet on x](https://twitter.com/zX14_7/status/2064853015622775047)
>
> **June 14 bug-fix release:** 8 critical bugs fixed β seed corpus now actually ingested,
> node lifecycle corrected (`stop()` previously silently no-oped), sticky session memory
> leak patched, corpus writes go to the right directory.
> See [hackathon_final_step.md](hackathon_final_step.md) for the full analysis.
---
## The Idea
What happens to your neighbourhood's AI when the power grid flickers, the ISP goes down, or the cloud API bill hits?
**HearthNet answers: nothing changes.** It keeps running.
Every household with a Raspberry Pi, an old laptop, or any device running Python becomes a **node**
in a local AI mesh. Nodes find each other automatically over Wi-Fi, share capabilities through an
intelligent routing bus, and work **completely offline**. When the internet is available, nodes **automatically route requests to the best provider** β whether local, nearby on LAN, or across the internet via relay. You see exactly which node answered.
- A neighbourhood of 10 homes gets **10Γ the AI capacity** of any single device
- **Offline-first**: all features work without internet; internet is optional for mesh expansion
- **Transparent routing**: every Ask/Chat/RAG request shows which node served it (local or remote)
- Ask questions, share knowledge, send messages, coordinate emergency response β all offline
- No cloud account, no API key, no monthly bill β hardware you already own
---
## Features
### Agent Mode (ReAct tool calling)
Flip the **Agent mode** toggle in the Ask tab and the model stops being a chatbot and starts being an **agent**: it plans, calls real mesh tools over several steps, reads the results, and only then answers. Every step is shown live β **Thought β Tool β Observation β Answer**.
The agent's tools are bound to **real capabilities already on the bus** (no mock handlers):
`search_corpus` (RAG), `list_corpora`, `translate`, `list_marketplace`, `route_expert` (MoE), and `identify_plant` (vision). The loop uses a JSON `action:` protocol that works even on **tiny models with no native function-calling** β so a 4B MiniCPM or Nemotron Mini can drive the same agent as a 49B reasoner. There is also a **fully in-browser WebLLM agent** (WebGPU, zero server) for true offline tool use.
> π‘ **Try the browser agent:** press **`a`** (or just type **`hearthnet`**) anywhere on the dashboard to open the in-browser WebLLM agent showcase. Press **`e`** for the live mesh/news ticker, **`Esc`** to close.
### π§ Intelligent Routing (NEW)
When you ask a question, the bus scores available LLM nodes by latency, load, and reliability. Your request goes to the **best node right now** β whether it's local, your neighbour's device, or a peer across the internet. Failover is automatic: if the preferred node can't help, the next-best provider takes over **invisibly**.
**Routing Trace** shows you exactly where your request was served:
- π **Local**: Answered by this device
- π **Remote (node-id)**: Routed to a peer node (LAN or internet)
- β **Error**: No suitable provider found
### π¬ Chat Over LAN & Internet
Direct 1:1 messages work completely offline on your Wi-Fi. Connect to the internet (via relay hub on HF Space) and chat with anyone in the mesh, regardless of network. No accounts, no passwordsβjust show them your QR code.
### π Federated RAG
Share a corpus of documents with your community. Any node can search across **all available corpora** automatically, with results ranked by relevance. Works offline on local copies; syncs and queries remote corpora when internet is available.
### π€ MOE Expert Routing
Nodes advertise their specialisations. Queries automatically route to the best experts in your mesh for better answers.
### π¨ Emergency Mode
When connectivity drops, the UI automatically switches to degraded mode. Nodes keep working offline. When restored, changes sync. Perfect for neighbourhood coordination during outages.
---
## Screenshots
Ask the Mesh
Live Peer Topology
Routing Trace
Community Marketplace
Direct Messages
Invite QR Code
Emergency Mode
All 8 Tabs
---
## π¦ Downloads & Builds
Get HearthNet for your platform:
| Platform | Download | Format | Size | Notes |
|----------|----------|--------|------|-------|
| **Android (PWA)** | [Web App](https://huggingface.co/spaces/build-small-hackathon/HearthNet) | Web | ~5MB | Install from browser - no download needed |
| **Android (Native)** | [app-debug.apk](https://huggingface.co/spaces/build-small-hackathon/HearthNet/resolve/main/build/android/HearthNetApp/platforms/android/app/build/outputs/apk/debug/app-debug.apk) | APK | 3.56MB | Native Android app via USB or direct install |
| **Windows Desktop** | [HearthNet.exe](https://huggingface.co/spaces/build-small-hackathon/HearthNet/resolve/main/dist/HearthNet.exe) | EXE | 212MB | Standalone executable - download & run |
| **Linux Desktop** | `python build/quickstart.py linux` | AppImage | ~120MB | Build on Linux or use script |
| **macOS Desktop** | `python build/quickstart.py macos` | .app | ~200MB | Native macOS app bundle |
| **Python (Any OS)** | [Source](https://github.com/ckal/HearthNet) | Python | - | `python app.py` - full mesh node |
| **Docker** | [Dockerfile](Dockerfile) | Container | 2GB | `docker run -p 7860:7860 hearthnet:latest` |
| **Guides & Docs** | [BUILD_GUIDE.md](docs/guides/BUILD_GUIDE.md) | Markdown | - | How to build for each platform |
**Recommended Paths:**
- π **Fastest** (5 min): PWA Web App - instant, no install
- π» **Desktop** (3 min): Download EXE/AppImage and run
- π³ **Server**: Docker container deployment
- π See [BUILD_GUIDE.md](docs/guides/BUILD_GUIDE.md) for detailed instructions
---
## Quick Start
```bash
# Clone and install
git clone https://huggingface.co/spaces/build-small-hackathon/HearthNet
cd HearthNet
pip install -e ".[dev]"
# Run
python app.py # open http://127.0.0.1:7860
```
### With llama.cpp (recommended β fast, offline)
```bash
# 1. Download a GGUF model
wget https://huggingface.co/lmstudio-community/Meta-Llama-3.1-8B-Instruct-GGUF/resolve/main/Meta-Llama-3.1-8B-Instruct-Q4_K_M.gguf
# 2. Start llama.cpp server
./llama-server -m Meta-Llama-3.1-8B-Instruct-Q4_K_M.gguf -p 8080
# 3. Run HearthNet (auto-detects llama.cpp on port 8080)
python app.py
```
**Why llama.cpp?**
- β‘ Fast inference on CPU (no GPU required)
- πΎ Runs the best models offline (8B params fits on 16GB RAM)
- π§ GGUF format is efficient and portable
- π No API key, no cloud, no latency
### Alternative: Ollama
```bash
ollama pull llama3.2:3b # any Ollama model works
python app.py # auto-detects Ollama
```
### On Android (PWA - Recommended)
```bash
# 1. Start HearthNet on your computer (Windows, Mac, or Linux)
python app.py
# 2. Find your computer IP address
# Windows: ipconfig | grep IPv4
# Mac/Linux: ifconfig | grep "inet " | grep -v 127
# 3. Open on Android device in Chrome/Firefox:
# http://:7860
# 4. Tap menu β "Install app" or "Add to Home screen"
```
**π± Full Android Setup Guide:** [ANDROID_DEPLOYMENT_GUIDE.md](docs/guides/ANDROID_DEPLOYMENT_GUIDE.md)
- β PWA (instant, no build)
- π§ Native APK (optional, advanced)
### Connect your local node to the live HF Space
```bash
# Get an invite code from the Space Settings tab
# Then redeem it locally:
python -m hearthnet.cli invite redeem \
"hnvite://v1/hf-space-1c95381d?host=build-small-hackathon-hearthnet.hf.space&port=443&transport=https&level=member"
python -m hearthnet.cli peers # Space node should appear
```
---
## How It Works
### Capability Bus
Every feature is a **named capability** on the bus. Any node can call any capability;
the bus routes to the best available provider automatically:
```python
# LLM inference β routes to fastest/best node in the mesh
result = await bus.call("llm.chat", (1, 0), {
"input": {"messages": [{"role": "user", "content": "What plants grow near water?"}]}
})
# RAG β routes to the node holding that corpus
result = await bus.call("rag.query", (1, 0), {
"params": {"corpus": "community"},
"input": {"query": "emergency water purification", "k": 3}
})
# Or from the CLI β no Python needed
python -m hearthnet.cli call llm.chat 1 0 '{"input":{"messages":[{"role":"user","content":"Hello!"}]}}'
python -m hearthnet.cli capabilities # list all available capabilities across mesh
```
### Zero-Config Discovery
```bash
# Device 1 β already running
python app.py
# Device 2 β same Wi-Fi
python app.py
# Both nodes see each other in ~5 seconds (mDNS + UDP broadcast)
# No IP addresses, no router config, no firewall rules
```
### Intelligent Routing & Failover
When you ask a question:
1. **Scoring**: Bus evaluates all LLM providers by latency, load, reliability, and local preference
2. **Selection**: Request goes to the best provider
3. **Failover**: If that node can't help (error or unavailable), automatically try the next-best alternative
4. **Tracing**: Result includes `_routed_via` showing which node served it
```python
# Node A has no LLM backend (would normally fail)
# Node B has llama.cpp running
# You ask Node A a question β Node A routes to Node B β B answers β A shows you the result
# Tracing shows: "_routed_via": "node-b-id"
result = await bus.call("llm.chat", (1, 0), {...})
# result includes "_routed_via": "node-b-id" β Shows the true origin
```
### MoE Expert Routing
Nodes advertise specialisations. Queries route to the best expert automatically:
```python
# A medical Raspberry Pi registers itself:
await bus.call("moe.register", (1, 0), {
"input": {
"expert_id": "model:medical-pi",
"topic_tags": ["first_aid", "medication", "triage"],
"confidence_score": 0.90,
}
})
# Any node's medical query now routes there:
result = await bus.call("moe.route", (1, 0), {
"input": {"query": "emergency first aid for burns", "top_k": 3}
})
# β {"candidates": [{"expert_id": "model:medical-pi", "score": 0.94}]}
```
### Offline Model Distribution
A node without internet pulls model weights from a LAN peer, chunk by chunk:
```python
models = await bus.call("model.list", (1, 0), {"input": {}})
job = await bus.call("model.pull", (1, 0), {
"input": {"model_name": "llama3.2:3b", "source_node": "peer-id"}
})
# Progress via model.status; BLAKE3 content-addressed so never duplicated
```
---
## What Makes This "Tiny"
The HF Space demo uses **SmolLM2-135M** β 135 million parameters, ~270 MB RAM.
For local installs, any GGUF model works (1Bβ8B for significantly better quality).
The architecture is model-agnostic; the routing layer handles the rest.
**Real semantic RAG, not a toy:** when `sentence-transformers` is installed the
embedding service loads `BAAI/bge-small-en-v1.5` (~130 MB, CPU-friendly) so
`rag.query` performs genuine semantic retrieval. Without it, the service falls
back to a deterministic hash embedder and says so β no silent fakery.
**Why this qualifies for Tiny Titan:**
A full mesh of 10 Raspberry Pi 4 nodes (4 GB RAM each) can run:
- 135M model locally per node (always available, zero latency)
- Load-balanced routing for larger models across the mesh
- Full offline capability: discovery, RAG, chat, marketplace β no internet needed
---
## Local AI Backends
**No mocks. No fake responses. Real local inference only.**
HearthNet prioritizes local, private models. Cloud backends are **opt-in only** (env vars).
### Local Backends (Primary)
| Backend | Activation | Notes |
|---------|-----------|-------|
| **llama.cpp** (recommended) | Start server on port 8080 + auto-detect | Any GGUF model; fastest on CPU |
| **Ollama** | `ollama pull llama3.2:3b` + auto-detect | 70+ models, easy management |
| **HF Transformers** | Default on HF Space (no config needed) | SmolLM2-135M, CPU-friendly |
| **OpenBMB / MiniCPM** | `MINICPM_URL` env var (local server) | Local-first, OpenAI-compatible API |
### Optional Cloud Backends (Opt-In via Env Vars)
| Backend | Activation | Notes |
|---------|-----------|-------|
| **NVIDIA Nemotron** | `NVIDIA_API_KEY` env var | For RTX nodes: nemotron-70b/mini-4b |
| **Modal** | `MODAL_ENDPOINT` env var | Serverless GPU inference |
| **OpenAI API** | `OPENAI_API_KEY` env var | Fallback only; not recommended for offline mesh |
All configured backends are registered on the `llm.chat` capability. The routing bus selects the best backend based on:
1. **Local first**: llama.cpp, Ollama, HF Transformers always preferred
2. **Load & latency**: If you have multiple local nodes, asks route to the least-busy one
3. **Failover**: If local is unavailable and you have internet, remote nodes or cloud backends are tried
If no suitable backend is available: clear error message returned. Never silent, never fabricated.
---
## Security
- **Ed25519** β all node manifests and invite links signed with PyNaCl
- **X3DH + Double Ratchet** β end-to-end encrypted chat (M23)
- **BLAKE3** β content-addressed file blobs (tamper-evident)
- **localhost-only CLI** β all admin HTTP restricted to 127.0.0.1
- **Capability token `exp` claim** β checked in `bus.handle_call()` before routing; expired tokens receive `{"error": "token_expired"}` without hitting any handler
- **Token signature verification** β Ed25519 signature checking is implemented in `AuthService` (`auth.token.verify`) and is available on the bus. The HTTP transport (`/bus/v1/call`) currently passes tokens to `handle_call()` where expiry is enforced; full per-request signature verification on inbound HTTP calls is a planned hardening step.
- **Bandit HIGH findings: 0** (verified in CI)
---
## Architecture
```
βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β Gradio UI (8 tabs) β
β Ask Β· Chat Β· Mesh Β· Marketplace Β· Files Β· Emergency Β· β
β Settings Β· Getting Started β
βββββββββββββββββββββββββββ¬ββββββββββββββββββββββββββββββββββ
β
ββββββββββββββΌβββββββββββββ
β Capability Bus (M03) β
β route Β· score Β· trace β
ββββββ¬βββββββ¬βββββββ¬βββββββ
β β β
ββββββββββββΌβ ββββΌββββ ββΌβββββββββββ ββββββββββββββ
β LLM (M04) β β RAG β β MoE (M27) β β Chat (M10) β
βllama.cpp β β(M05) β β Expert β β Marketplaceβ
β Ollama β βSQLiteβ β Registry β β (M06) Filesβ
βHF Transfm β βEmbed β βββββββββββββ ββββββββββββββ
βββββββ¬ββββββ ββββ¬ββββ
βββββββ¬βββββββ
ββββββββββββββββΌβββββββββββββββββββββββββββββββββββββββ
β Transport (X01) Β· Discovery (M02 mDNS/UDP) β
β Events (X02 SQLite/Lamport) Β· E2E Encrypt (M23) β
β Identity (M01 Ed25519) Β· Observability (X03) β
βββββββββββββββββββββββββββββββββββββββββββββββββββββββ
```
---
## Module Reference
Phase 1 β Core (M01βM13, X01βX04) Β· 17 modules
| Module | Description | Status |
|--------|-------------|--------|
| M01 | Node identity (Ed25519, manifests, canonical JSON) | β |
| M02 | Peer discovery (mDNS, UDP broadcast, PeerRegistry) | β |
| M03 | Capability bus (schema validation, routing, tracing) | β |
| M04 | LLM service (llama.cpp, Ollama, HF Transformers, cloud fallback) | β |
| M05 | RAG (chunker, SQLite/ChromaDB vector store, IngestPipeline, federated scatter-gather) | β |
| M06 | Marketplace (event-sourced, Lamport-clocked posts) | β |
| M07 | File blobs (BLAKE3 hash, content-addressed, chunked transfer) | β |
| M08 | Gradio UI (8 tabs: Ask, Chat, Mesh, Marketplace, Files, Emergency, Settings, Getting Started) | β |
| M09 | Emergency mode (async connectivity probe, auto-degrade on offline) | β |
| M10 | Chat (event-backed 1:1 direct messaging, Lamport delivery order) | β |
| M11 | Embeddings (embed.text, SentenceTransformer `bge-small-en-v1.5`, SimpleHashBackend fallback, batch support) | β |
| M12 | CLI (click, ask / peers / marketplace / call / capabilities) | β |
| M13 | Onboarding (invite QR, hnvite:// deep links, PyNaCl signing) | β |
| X01 | Transport (FastAPI server, 12 REST endpoints, TLS) | β |
| X02 | Events (SQLite, Lamport clocks, ReplayEngine, snapshots) | β |
| X03 | Observability (structured JSON logging, metrics, distributed tracing) | β |
| X04 | Config (typed frozen dataclasses, TOML, env overlay) | β |
Phase 2 β Advanced (M14βM25, X05βX07) Β· 18 modules
| Module | Description | Status |
|--------|-------------|--------|
| M14 | Federation (bilateral cross-community trust, manifest signing) | β |
| M15 | Relay tier (NAT traversal, keepalive, push token registry) | β |
| M16 | Capability tokens (Ed25519 JWS-style hntoken://v1/ format) | β |
| M17 | OCR (Tesseract + TrOCR backends, graceful degradation) | β |
| M18 | Translation (NLLB backend, LRU cache, 4000-char limit) | β |
| M19 | STT/TTS (Whisper local STT, Edge TTS synthesis) | β |
| M20 | Vision (Florence-2 image describe, structured output) | β |
| M21 | Tool calls (LLM mid-generation bus dispatch, ToolExecutor, plant_identify) | β |
| M22 | Mobile native (Flutter contract, hnapp:// invites, push authority) | β |
| M23 | E2E encryption (X3DH key agreement, Double Ratchet, AEAD envelope) | β |
| M24 | Reranking (BGE + CrossEncoder backends, 100-doc limit) | β |
| M25 | Group chat (ThreadService, ThreadViewStore, event-sourced threads) | β |
| X05 | DHT (Kademlia node, 256-bucket routing table, bootstrap) | β |
| X06 | WebSocket upgrade (bidirectional pubsub, WsClient) | β |
| X07 | Federated metrics (NodeMetricsTick, MetricsAggregator, OTLP) | β |
Phase 3 β Experimental (M26βM31, X08βX09) Β· feature-flag gated
| Module | Description | Status |
|--------|-------------|--------|
| M26 | Distributed inference (ShardDescriptor, PipelineOrchestrator, model.pull) | registered |
| M27 | MoE routing (ExpertRegistry, MoeRouter, moe.route/register/list) | registered |
| M28 | Federated learning (FedLearnCoordinator, RoundManifest, gradient aggregation) | experimental |
| M29 | LoRa beacons (32-byte frames, 868 MHz offline signaling) | experimental |
| M30 | Evidence graph / EBKH (ClaimStore, attestations, disputes) | experimental |
| M31 | Civil defense NRW (AuditChain, role certs, structured alerts) | experimental |
| X08 | Tensor transport (chunked binary tensor streaming) | experimental |
| X09 | Conformance suite (protocol test harness) | experimental |
---
## π§ͺ Testing & Coverage
### Comprehensive Test Suite: 390+ Tests
HearthNet includes rigorous tests for all core capabilities:
| Suite | Count | Coverage |
|-------|-------|----------|
| **Phase 1 Core** (M01-M13, X01-X04) | 120+ | Bus routing, discovery, identity, emergency mode |
| **Intelligent Routing** (NEW) | 8+ | Failover, latency scoring, tracing, stamping |
| **Chat & Messaging** (M10) | 35+ | Direct messages, cross-node delivery, event-sourced |
| **RAG & Search** (M05) | 25+ | Local corpus, semantic search, federated queries |
| **LLM Service** (M04) | 20+ | Multiple backends (llama.cpp, Ollama, HF), model selection |
| **Integration** | 40+ | Real services wired together, marketplace, file blobs |
| **UI & E2E** | 20+ | All 8 tabs, Gradio API, user workflows |
| **Phase 2/3 Advanced** | 70+ | Federation, crypto, DHT, MoE, group chat |
| **Total** | **390+** | Python 3.13 Β· pytest-asyncio Β· Full async test suite |
### Run Tests Locally
```bash
# Full suite
python -m pytest tests/ -v
# Specific module (e.g., routing tests)
python -m pytest tests/test_bus_failover.py -v
# With coverage report
python -m pytest tests/ --cov=hearthnet --cov-report=term-missing
# Skip slow E2E tests
python -m pytest tests/ --ignore=tests/test_e2e_user_stories.py -v
```
**All tests pass** on Python 3.13 with pytest-asyncio.
**Focus areas:**
- β Well-covered: Bus routing, identity, chat, discovery, emergency mode
- π― Strong: LLM service, RAG pipeline, marketplace, event system
- π Expanding: Transport layer, UI advanced features, observability metrics
---
## π Deployment & Source
| Resource | Purpose |
|----------|---------|
| **HF Space** (Primary) | [https://huggingface.co/spaces/build-small-hackathon/HearthNet](https://huggingface.co/spaces/build-small-hackathon/HearthNet) | Live demo + Downloads |
| **GitHub** (Mirror/CI) | [https://github.com/ckal/HearthNet](https://github.com/ckal/HearthNet) | Source control + Issue tracking |
**Deployment Architecture:**
- π‘ **HF Space**: Live demo, PWA app, binary downloads (exe, apk, etc.)
- π **GitHub**: Source repository, CI/CD, releases, issue tracking
- π **Sync**: Changes push to both simultaneously
**Build Artifacts Available:**
- Windows EXE: [dist/HearthNet.exe](https://huggingface.co/spaces/build-small-hackathon/HearthNet/resolve/main/dist/HearthNet.exe) (212 MB)
- Android APK: [build/android/.../app-debug.apk](https://huggingface.co/spaces/build-small-hackathon/HearthNet/resolve/main/build/android/HearthNetApp/platforms/android/app/build/outputs/apk/debug/app-debug.apk) (3.56 MB)
- Build scripts: [BUILD_GUIDE.md](docs/guides/BUILD_GUIDE.md) for EXE, AppImage, .app, Docker
---
## Contributing & Docs
| Resource | Link |
|----------|------|
| Architecture | [ARCHITECTURE.md](docs/ARCHITECTURE.md) |
| System overview | [docs/00-OVERVIEW.md](docs/00-OVERVIEW.md) |
| Capability contract | [docs/CAPABILITY_CONTRACT.md](docs/CAPABILITY_CONTRACT.md) |
| Roadmap | [docs/roadmap.md](docs/roadmap.md) |
| Task tracker | [tasks.md](tasks.md) |
| Phase 2+3 specs | [docs/p2_p3/](docs/p2_p3/) |
---
## Hackathon Entry
**Track:** ποΈ Backyard AI (Practical)
**Why HearthNet wins:**
π **Tiny Titan:** Runs on SmolLM2-135M (135M params). Full mesh on Raspberry Pi 4. Every device runs real inference locally.
π€ **Best Agent:** Capability bus + intelligent routing = distributed agentic system. Nodes score, select, and failover to the best provider autonomously. MOE expert routing means each specialist node attracts the right queries.
**Optional integrations:**
- NVIDIA Nemotron: Document intelligence for RAG (`NVIDIA_API_KEY` env var)
- OpenBMB MiniCPM: Local-first models via `MINICPM_URL` (llama.cpp-compatible)
- Modal: Serverless GPU as remote node (`MODAL_ENDPOINT` env var)
---
## Links
| | |
|--|--|
| π€ HF Space (Live) | https://huggingface.co/spaces/build-small-hackathon/HearthNet |
| π GitHub (Source) | https://github.com/ckal/HearthNet |
| π Architecture | [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md) |
| π§ͺ Tests | `python -m pytest tests/ -v` |
---
Built with open source models and the belief that communities should own their AI. Small model. Big mesh. Real resilience.