> For the complete documentation index, see [llms.txt](https://guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guardian.hedera.com/welcome.md). # Welcome ## The official [Hedera Guardian](https://guardian.hedera.com/) documentation The Hedera Guardian is an open-source platform for creating, managing, and issuing digital environmental assets. Examples include credit issuance for carbon, renewable energy, and biodiversity; emission and financial disclosures; certifications; climate-smart commodities; and more. Through forms, automated workflows, and connected data streams, it links project developers, auditors, corporates, and standards bodies in a shared ecosystem, using the [Hedera network](https://hedera.com/?utm_source=guardian) as the trust layer. It leverages a customizable workflow engine, calculation engine, verifiable-credential based identity management, and web3 technology to ensure transparent and fraud-proof operations, making it a key tool for transforming sustainability practices and environmental markets. ### **Methodology Digitalization and Trust** Environmental markets depend on trust: trust that issued credits represent real and verifiable outcomes, that data hasn't been altered, and that the methodology and calculations behind a claim are sound. In the past, that trust was enforced through manual audits, closed registries, and siloed spreadsheets: developers and standards bodies routinely spent over $500,000–$1M+ to digitalize a single complex, 100+ page environmental methodology. Today, Guardian makes it programmable through **methodology digitalization**. Guardian policies encode methodology rules directly, the Hedera Network provides an immutable audit trail, and verifiable credentials let any participant confirm the chain of custody without needing to trust a central intermediary. This lowers costs, improves speed and efficiency, while accelerating collaboration across domains such as finance, technology, compliance, and ecology. #### Want to learn more about methodology digitalization? [View the best practices guide to get started.](/methodology-digitalization/methodology-digitalization-best-practices.md) ### **Platform at a glance** Guardian is built around a number of core aspects and understanding how they relate is a good foundation to navigate the docs further. * **Guardian Policies** are the rules of an environmental methodology and can include data collection forms, role-based approval workflows, calculations, and dMRV endpoints all of which are run as executable software rather than static PDF documents. *A policy for Verra VM0047 specifies exactly what a project proponent submits, what a verifier approves, and how credits are calculated and issued.* * **Schemas** define the structure of every data submission within a policy — fields, types, and validation rules that make data submissions consistent and machine-readable. *A renewable energy certificate schema requires meter ID, generation timestamp, and grid region.* * **Calculation Engine** runs math blocks and formula-linked definitions within a policy, turning verified data into calculated quantities. *A water-quality policy converts nutrient-load reductions into tradable credits, while a carbon policy applies leakage, uncertainty, and buffer-pool deductions to net GHG results.* * **Tokens** are the digital environmental assets produced at key points within a policy workflow and represent outcomes recorded on the Hedera network. *A carbon project mints credits from a shared buffer pool.* * **TrustChain** is the verifiable audit trail that links every token back to the original submissions, approvals, and calculations that produced it. Any participant can inspect the full chain of custody without relying on a central intermediary. *A deforestation-free supply chain claim is traced end-to-end through every custody handoff to verify compliance.* * **Standard Registry** is the platform role that publishes policies, onboards project participants, and manages credit issuance. It is the organizing entity for everything that happens in Guardian. *A voluntary carbon credit registry manages the authoring, review, and testing workflows for policies that implement the environmental methodologies they have developed.* * **Methodology Library** is the world's largest open source repository of digitalized environmental methodologies. Anyone can download, import, inspect, test, and run these methodologies. The authoring process continues to be improved through global collaborations and feedback helping to bring costs down for all. *A hackathon participant develops a wildfire fuel reduction methodology and publishes it to the Library; a metered energy cookstove methodology is updated from version 1.2 to 2.0 for registry testing and project developer adoption.* ### **Platform adopters and ecosystem** Adoption of the Guardian has grown from an early concept in 2020 to a platform being used by dozens of innovative companies including the world’s leading carbon standards and auditors; project developers and enterprises. Ecosystem members have shared back 100+ open source contributors via GitHub, successfully issued numerous types of environmental assets, formed commercial partnerships, and developed the worlds largest open source methodology library. As you explore the platform, you'll notice mature capabilities developed in collaboration with a global ecosystem of stakeholders and community members — who we're grateful and proud of. ### **Where to start** | I want to… | Start here | | --------------------------------------- | ------------------------------------------------------------------------------------------------------ | | Install and run Guardian | [Getting Started](/guardian/getting-started.md) | | Create and publish policies | [Workspace](/guardian/workspace.md) | | Digitalize an environmental methodology | [Methodology Digitalization](/methodology-digitalization/methodology-digitalization-best-practices.md) | | Build on the Guardian API | [API Reference / guardian](https://guardian.hedera.com/api-reference-guardian/) | | Explore what's published by Guardian | [Explorers](/explorers/explorers-overview.md) | ### **Hedera Network Foundations** Guardian publishes policy workflow data to the Hedera Network to support discovery and traceability. Guardian records Hedera Consensus Service transactions in topics. A token mint transaction can include a memo identifier that points to a Hedera message timestamp. That message contains the URL of the related Verifiable Presentation (VP). The VP links the Verifiable Credentials produced by the policy workflow. Together, these records provide the starting point for tracing the documents behind a token. {% hint style="info" %} HIP-19 and HIP-28 established foundational Hedera capabilities used by the Guardian on the Hedera Network {% endhint %} [HIP-19](https://hips.hedera.com/hip/hip-19) and [HIP-28](https://hips.hedera.com/hip/hip-28) define this foundational approach. Guardian builds on it through the [TrustChain](/docs/develop/guardian/platform/trustchain.md). ### **Open source community** Establishing trust across climate and environmental markets is a hard, shared problem. No single organization can build the infrastructure that markets need on its own. Guardian exists because the problem requires open collaboration — on methodology digitalization, on verification standards, and technical workflows — to accelerate solutions to tough challenges. Guardian is open source under the Apache 2.0 License and developed collaboratively by Hashgraph alongside carbon registries, auditors, project developers, governments, and enterprises building on the platform. Policies in the Methodology Library are contributed by organizations worldwide by registries, methodology authors, and independent developers. Community calls, hands-on training sessions, and design workshops are regularly hosted. If you are building on the Guardian, digitizing a methodology, or improving the platform itself — contributions and feedback is welcome. * [Contributing](/community-and-contributing/contributing.md) * [Community Standards](/community-and-contributing/community-standards.md) * [Methodology Library](https://github.com/hashgraph/guardian/tree/main/Methodology%20Library) * [GitHub Milestones](https://github.com/hashgraph/guardian/milestones?sort=due_date\&direction=asc) * [Share feedback or suggestions](mailto:guardian-feedback@hashgraph.com) #### **Related** * Concepts: [Architecture](/guardian/architecture.md) * Guide: [Methodology Digitalization](/methodology-digitalization/methodology-digitalization-best-practices.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. 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