> For the complete documentation index, see [llms.txt](https://hub.bsvblockchain.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hub.bsvblockchain.org/demos-and-onboardings/demo-solutions/demos/truth-machine/technical-truth-machine.md). # Technical Documentation **Demo ID**: `demo-2025-001` **Version**: `1.0.0` **Last Updated**: `August 2025` ## Overview Truth Machine is a blockchain-based data integrity and timestamping system built on BSV. It provides immutable proof of data existence and integrity by recording cryptographic hashes on the blockchain. *** ## Features * **Secure File Storage**: Upload files with blockchain-backed integrity verification * **Timestamping**: Immutable proof of data existence at a specific time * **Integrity Verification**: Download files with cryptographic proof of integrity * **BEEF Integration**: [Background Evaluation Extended Format for complete transaction verification](https://hub.bsvblockchain.org/brc/transactions/0062) * **Treasury Management**: Built-in token system for managing transaction fees * **QR Code Support**: Easy funding through QR code scanning * **Modern Web Interface**: User-friendly React-based frontend *** ## System Architecture ### Frontend (React + TypeScript) * Modern React application with TypeScript * Real-time treasury balance monitoring * Intuitive file upload/download interface * QR code generation for funding ### Backend (Node.js + Express) * RESTful API endpoints for file operations * [BEEF transaction format support](https://hub.bsvblockchain.org/brc/transactions/0062) * Blockchain integration via WhatsOnChain * MongoDB for file and transaction storage *** ## Quick Start Guide Prerequisites: Latest versions of Docker Compose and Node.js. The `start.sh` script assumes macOS/Unix environment. ### Setup ```bash git clone https://github.com/bsv-blockchain-demos/truth-machine.git cd truth-machine sh quickstart.sh ``` This script will install dependencies for frontend and backend, generate local keys, update your `.env` and `docker-compose.yml`, then launch the application. ### Reverse Proxy Setup To route API callbacks, set up a public tunnel: ```bash ngrok http 3030 ``` Copy the public URL and update `DOMAIN` variable in `.env` or `docker-compose.yml` accordingly. ### Stopping and Restarting Stop services: ```bash docker compose down ``` Restart without destroying the environment: ```bash docker compose up ``` *** ## Running the Application ### Development Mode ```bash cd back npm run dev cd ../front npm run dev ``` ### Production Mode ```bash cd back
npm run build npm run start cd ../front npm run build npm run preview ``` ### Using Docker Build images: ```bash docker compose build ``` Run containers: ```bash docker compose up ``` *** ## Usage Guide ### Treasury Management * Access Treasury section to see balance * Fund treasury by scanning QR code with BSV * Create write tokens for uploading files (1 token per upload) ### File Upload 1. Navigate to Upload section 2. Select a file for upload 3. System calculates cryptographic hash, writes transaction on-chain, securely stores file, and provides transaction ID and proof ### File Download 1. Navigate to Download section 2. Input file hash or transaction ID 3. Receive original file, timestamp proof, integrity verification, and BEEF transaction data *** ## API Endpoints ### File Operations * `POST /api/upload` — Upload and timestamp file * `GET /api/download/:hash` — Download file and proofs * `GET /api/verify/:hash` — Verify file integrity ### Treasury Operations * `GET /api/checkTreasury` — Get treasury balance * `POST /api/fund/:tokens` — Create upload tokens *** ## Security Features * [BEEF format for transaction verification](https://hub.bsvblockchain.org/brc/transactions/0062) * Simplified Payment Verification (SPV) * SHA-256 file hash verification * Immutable blockchain-backed timestamping *** ## Development Environment ### Prerequisites * Node.js 18+ * MongoDB 4.4+ * BSV wallet for testing ### Testing Run backend tests: ```bash cd back npm test ``` Run frontend tests: ```bash cd front npm test ``` ### Validation Criteria * Functional tests for upload, download, and verification APIs * Performance tests simulate upload and retrieval under load ## Performance & Scalability ### Current Metrics * Response times typically under 500 ms for API operations * Supports thousands of timestamped files with MongoDB indexing * Scalable via Docker orchestrators or Kubernetes ### Scalability Considerations * Token treasury ensures sufficient transaction fee coverage * MongoDB sharding for large-scale file storage * Caching of blockchain responses to reduce API load ## Maintenance & Support ### Monitoring * Logs accessible via Docker or node logging systems * Metrics dashboard can be integrated with external monitoring tools ### Troubleshooting | Issue | Cause | Solution | | -------------------------- | ------------------------ | -------------------------------------------------- | | API not reachable | Backend not running | Restart backend service, check logs | | File upload fails | Insufficient tokens | Fund treasury with BSV tokens | | Blockchain write fails | Network or API problem | Check WhatsOnChain service status | | Verification returns false | Data tampering or errors | Confirm file integrity and latest blockchain state | ## Resources * **Repository**: * **Business Documentation**: [Link to business-truth-machine.md](/demos-and-onboardings/demo-solutions/demos/truth-machine/business-truth-machine.md) * **Demo Environment**: * **Support Contact**: bsv-blockchain GitHub issues page *** *For business context and ROI details, see:* [*Business Documentation*](/demos-and-onboardings/demo-solutions/demos/truth-machine/business-truth-machine.md) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://hub.bsvblockchain.org/demos-and-onboardings/demo-solutions/demos/truth-machine/technical-truth-machine.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.