Introducing Block Streams: A Unified Data Stream Capturing… | Hedera Hedera Network Services Token Service Mint and configure tokens and accounts. Consensus Service Verifiable timestamps and ordering of events. Smart Contracts Run Solidity smart contracts. HBAR The Hedera network's native cryptocurrency. Insights How It Works Learn about Hedera from end to end. Explorers View live and historical data on Hedera. Dashboards Analyze network activity and metrics. Network Nodes Understand networks and node types. Devs Start Building Get Started Learn core concepts and build the future. Documentation Review the API and build using your favorite language. Developer Resources Integrations Plugins and microservices for Hedera. Fee Estimator Understand and estimate transaction costs. Open Source Hedera is committed to open, transparent code. Learning Center Learn about web3 and blockchain technologies. Grants Grants & accelerators for your project. Bounties Find bugs. Submit a report. Earn rewards. Ecosystem ECOSYSTEM Hedera Ecosystem Applications, developer tools, network explorers, and more. NFT Ecosystem Metrics Analyze on-chain and market NFT ecosystem metrics. CATEGORIES Web3 Applications Connect into the innovative startups decentralizing the web on Hedera. Enterprise Applications Learn about the Fortune 500 companies decentralizing the web on Hedera. Wallets & Custodians Create a Hedera account to manage HBAR, fungible tokens, and NFTs. Network Explorers Hedera mainnet and testnet graphical network explorers. Developer Tooling Third-party APIs, integrations, and plugins to build apps on Hedera. Grants & Accelerators Boost your project with support from the Hedera ecosystem. Partner Program Explore our partners to bring your vision into reality. Hedera Council Over 30 highly diversified organizations govern Hedera. Use Cases Hedera Solutions Asset Tokenization Studio Open source toolkit for tokenizing assets securely. Stablecoin Studio All-in-one toolkit for stablecoin solutions. Hedera Guardian Auditable carbon markets and traceability. Functional Use Cases Data Integrity & AI Reliable, secure, and ethically governed insights. Sustainability Enabling fair carbon markets with trust. Real-World Asset Tokenization Seamless tokenization of real-world assets and digital at scale. Consumer Engagement & Loyalty Mint, distribute, and redeem loyalty rewards. Decentralized Identity Maintain the lifecycle of credentials. Decentralized Logs Scalable, real-time timestamped events. DeFi Dapps built for the next-generation of finance. NFTs Low, fixed fees. Immutable royalties. Payments Scalable, real-time, and affordable crypto-payments. HBAR Overview Learn about Hedera's token, HBAR. Treasury Management Hedera’s report of the HBAR supply. Governance Decentralized Governance Hedera Council See the world's leading organizations that own Hedera. About Meet Hedera's Board of Directors and team. Journey Watch Hedera's journey to build an empowered digital future for all. Transparent Governance Public Policy Hedera's mission is to inform policy and regulation that impact the industry. Meeting Minutes Immutably recorded on Hedera. Roadmap Follow Hedera's roadmap in its journey to build the future. Resources Company What's New Partners Papers Careers Media Blog Technical Press Podcast Community Events Meetups Store Brand Navigation QUICKSTART Introducing Block Streams: A Unified Data Stream Capturing the Comprehensive History of the Hedera Network technical Dec 27, 2024 by Mark Blackman Senior Director of Product, Hashgraph by Mica Cerone Community Development, Hashgraph Introducing Block Streams: A Unified Data Stream Capturing the Comprehensive History of the Hedera Network The upcoming Hedera network upgrade introduces early access to HIP-1056: Block Streams, a new blockchain format for recording the Hedera network's activities. This innovation marks a big step forward with all transaction output and state change data being exposed in a single, cryptographically verifiable stream of data. Block Streams will consolidate current output streams into a single, unified format. Moreover, the inclusion of Hedera state data redefines how developers and services interact with the network, enabling richer insights, improved efficiency, and streamlined integrations.  TL;DR Block Streams are a new output stream that merges Hedera’s existing event, record, and sidecar streams into a single stream of verifiable data. This consolidated approach primarily simplifies data consumption; however, with the inclusion of state data, it also unlocks new capabilities such as state proofs and interledger communication. Each block within this stream is a self-contained, verifiable entity that encompasses: All events and transactions within a configurable number of consensus rounds. All resulting transaction output and state change data. A single network signature that attests to the validity of the block by a majority of Hedera mainnet nodes. Benefits of Blockstreams 1. Unified Data Stream Block Streams consolidate multiple data types into a single, cohesive stream, simplifying data consumption and processing for developers and services. 2. Enhanced Verifiability Each block includes a BLS network signature, proving it was signed by a majority of nodes representing a majority of the network's consensus stake weight. This feature simplifies the verification of the data, reducing mirror node processing and verification costs. 3. Simplified Consumption Block Streams are encoded using Protobuf, enabling them to be easily consumable by any programming language with minimal complexity or dependencies, which increases accessibility for developers to work with Hedera data. Unlocking Potential with State Changes Adding Hedera state change data unlocks significant advantages by enabling off-network computation and verification of state. This capability empowers developers and services to achieve high performance, enhanced efficiency, and greater flexibility. Some examples include: Applications and off-chain services can cache and process Hedera state locally, reducing latency and dependency on external data retrieval. Applications and off-chain services can monitor and maintain contract state locally, enabling seamless interaction with Hedera-based smart contracts. Technical Insights into Blockstreams Block Items A Block Stream is a continuous sequence of data elements, known as Block Items, streamed from Hedera consensus nodes to provide a verifiable record of Hedera consensus and transaction processing.  The sequence of Block Items is crucial for interpreting the Block Stream, as it not only defines the boundaries of individual blocks but also establishes the relationship between Block Items within a block. This ordered structure determines how blocks are extracted from the Block Stream, how transactions are linked to specific events, how events correlate with rounds, and how these components collectively define a block. The graphic below illustrates how the sequential ordering of Block Items represents the structure of a block and the data relationships connecting blocks, rounds, events, and transactions. Block Hash Within each block, the Block Items are organized into a Merkle-based tree structure, culminating in a root hash, known as the Block Hash. This structure ensures that each block’s data is consistent and accurately represented. This Block Hash is signed by a majority of consensus nodes using an aggregated signature, referred to as the Block Proof. The Block Proof provides cryptographic assurance that it has been processed, attested, and signed by a majority of Hedera mainnet nodes. Block Item Proof The Block Hash, Block Proof, and Merkle tree structure of a block open up new opportunities for leveraging Hedera's output data. Among these advancements are Block Item Proofs, which are cryptographic proofs for individual block items that allow verification of specific data within a block. These proofs empower users to independently verify all of Hedera’s transactional history at minimal cost, even for offline devices. This capability not only enhances trust and transparency but also significantly broadens the range of use cases for Hedera, from lightweight applications to secure offline verifications. Blockchain Structure Hedera functions as a modular blockchain, achieving consensus through the Hedera Hashgraph while outputting data into a blockchain structure. This architecture ensures the security and immutability of the network's historical records. Block Streams build on this foundation by incorporating the hash of each preceding block into the next block, forming an immutable chain of data derived from Hedera. The diagram below illustrates the Merkle tree structure within a block, showcasing how the previous block's hash is seamlessly integrated into the current one. This structure not only ensures data integrity but also enhances the transparency and auditability of the network. Transition to Block Streams When transitioning from the existing Hedera Record Stream to Block Streams, the hash of the final record file will be included as input to the first block. This ensures cryptographic continuity between the existing record stream and the new Block Stream format. Impacts on Mirror Nodes The Mirror Node software ensures a smooth transition from records to Block Streams and Block Nodes, offering an intuitive and straightforward upgrade process for operators. Additionally, the introduction of Block Streams brings significant features and benefits to Mirror Node operators and consumers, including the following: 1. Aggregated Signature – Less cost, less latency  Currently, each node generates a v6 record stream and a signature file for verification. Mirror Nodes must download signature files from a strong minority (1/3 of consensus stake) along with the record file, which makes frequent cloud storage access expensive. Blocks now include a single aggregated signature to cut costs and simplify the process. 2. File Naming and Retrieval – Less cost Record stream files are named after the first transaction's consensus timestamp, forcing mirror nodes to perform costly LIST operations on cloud storage to find new record files. The new Block Streams use sequential block numbers, removing the need for these operations. 3. Sidecar Inclusion – Lower complexity and processing In record streams, sidecar files store extra data—like smart contract logs—separately from the main record stream. Block Streams integrate this sidecar data into a unified stream, simplifying data management for Mirror Node operators. 4. Reduced Egress Currently, records streams are stored in cloud buckets, incurring egress charges for requesters. With the introduction of Block Nodes, Mirror Node operators have the flexibility to select their preferred Block Node, offering greater control over geolocation and reducing egress costs. Final Thoughts Block Streams mark a significant step in Hedera's evolution, providing a powerful new way to leverage network data for verification, transparency, and innovation. As we roll out this feature, we encourage your feedback and collaboration to explore the full potential of Block Streams to transform how we interact with and verify blockchain data. Together, we’re paving the way for a more connected, transparent, and efficient decentralized future. Starting with release 0.56, developers can access Block Streams, which will contain full mainnet blocks, including all data, except for the Block Proof, which will be mocked for development purposes. The blocks will be published to the Google Cloud Service (GCS) utilized by Hedera's record stream, adhering to the following structure: gs://hedera-mainnet-streams/block-preview/mainnet/0/3/000[..].blk.gz For more information, please visit: Hedera Documentation Share This Back to blog What is gRPC, gRPC-Web, and Proxies? Ed Marquez Pragmatic Blockchain Design Patterns – Integrating Blockchain into Business Processes Michiel Mulders Zero Cost EthereumTransaction on Success: Hedera's New Fee Model for Relay Operators Oliver Thorn Hedera Adopts Chainlink Standard for Cross-Chain Interoperability To Accelerate Ecosystem Adoption Hedera Team Hedera Developer Highlights March 2025 Michiel Mulders Hedera Release Cycle Overview Ed Marquez View All Posts Sign up for the newsletter CONNECT WITH US Transparency Open Source Audits & Standards Sustainability Commitment Carbon Offsets Governance Hedera Council Public Policy Treasury Management Meeting Minutes LLC Agreement Node Requirements Community Events Meetups HBAR Telegram Developer Discord Twitter Community Support FAQ Network Status Developer Discord StackOverflow Brand Brand Guidelines Built on Hedera Logo Hedera Store About Team Partners Journey Roadmap Careers Contact General Inquiry Public Relations © 2018-2025 Hedera Hashgraph, LLC. All trademarks and company names are the property of their respective owners. All rights in the Deutsche Telekom mark are protected by Deutsche Telekom AG. All rights reserved. Hedera uses the third party marks with permission. Terms of Use  |  Privacy Policy