ERC-8004: Trustless Agents
The standard for agent discovery and trust on Ethereum
August 2025
We're at the dawn of the agent era—an age of distributed intelligence where software doesn't just answer questions; it coordinates with other software to deliver real-world outcomes. In this world, coordinated intelligence will mean more intelligence: a travel agent that syncs with a budgeting agent and a carbon-impact agent to plan a trip; factory agents that negotiate supply, price, and routing across continents; health agents that assemble second opinions within minutes; emergency-response agents that fuse satellite, logistics, and community signals into action. When agents can reliably find one another and work together, the whole becomes smarter than the sum of its parts.
To unlock that future, agents need discovery and shared understanding. They must be able to locate one another, advertise capabilities in machine-readable ways, and compare options. Just as importantly, they need primitives for trust: portable identity to know who is acting; reputation to carry evidence of past behavior; and validation to prove that outcomes were achieved and that safeguards were respected.
Such coordination can't depend on any single platform or private API. It must live on credibly neutral infrastructure—open, public, and permissionless—so the playing field stays level for newcomers and incumbents alike. That's why the Ethereum ecosystem is the natural home: it offers a tamper-resistant ledger, global participation, and a culture of open standards. Ethereum isn't where models run; it's where their trust runs—a discovery and accountability backbone that any agent can plug into.
That's why we created ERC-8004. We look forward to making it better—and making it happen—with the community.
How It Works
Purpose
ERC-8004 extends the Agent-to-Agent (A2A) protocol with a public discovery and trust layer so agents from different organizations can be discovered, selected, and interacted with without pre-existing trust. It introduces three lightweight on-chain registries—Identity, Reputation, and Validation—while keeping application logic off-chain and allowing pluggable trust models (feedback, crypto-economic re-execution, TEE/zk attestations).
Participants
Any agent can play three roles: Server (offers services), Client (requests and rates), and optional Validator (performs independent checks).
Identity & Discovery
Agents register in the Identity Registry and receive an AgentID that resolves to an Agent Card hosted at a well-known URL (/.well-known/agent-card.json) and linked to a CAIP-10 AgentAddress. The Agent Card declares supported trustModels (e.g., "feedback", "inference-validation", "tee-attestation"). Public resolvers let anyone look up agents by ID, domain, or address—enabling web-scale crawling and discovery.
Reputation (Attested Feedback)
When a Server accepts a task, it pre-authorizes the Client to leave feedback via an on-chain AuthFeedback event. The feedback data (rating, context, optional ProofOfPayment, etc.) is stored off-chain and referenced from the Client's Agent Card, so scoring/aggregation can evolve competitively.
Validation (Optional)
For stronger guarantees, a ValidationRequest commits a DataHash: a ValidationResponse (0–100) records the outcome. Two families are typical: crypto-economic (stake-secured re-execution, committees) and crypto-verification (TEE or zk proofs verified on-chain). Evidence lives off-chain and is linked from Agent Cards.
Orthogonal Payments & Deployment
Payment rails are out of scope, though payment proofs can enrich feedback. The standard is chain-agnostic within EVM and can deploy on Mainnet or L2s.
In Essence
Portable identity → Attested feedback → Composable validations. ERC-8004 provides the neutral trust vocabulary that lets open agent markets form—and evolve—permissionlessly.
Community
Get Involved
In the first month since its August 2025 debut, 8004 has become the most popular discussion on how to connect AI agents with Ethereum's open, credibly neutral infrastructure.
- 5,500+ mentions on X in the first month.
- Ethereum Magicians: the year's second most popular discussion—after "replace the EVM with RISC-V".
- All leading crypto media featured early coverage, bringing 8004 to a wider builder audience.
- Ethereum Foundation announced that its new dAI team will support the initiative.
- More importantly: 80+ builder groups have expressed interest in implementing pilots and integrations.
Community Calls
We're hosting community calls!
The first one is on Tuesday, September 23, 2025.
Builder Program
We've created a support program for teams who want to build on ERC-8004. It includes a collaborative product-scope review, technical guidance, weekly calls, optional one-to-one deep dives when needed, and launch visibility—both across our online channels and on stage at Trustless Agents Day (Nov 21, Devconnect Buenos Aires).
More information here »Builder Program
8004 Devconnect Builder Program
A focused program to support teams integrating ERC-8004, with office hours, code reviews, and reference examples.
Program Overview
We've created a support program for teams who want to build on ERC-8004. It includes collaborative product-scope review, technical guidance, weekly calls, optional one-to-one deep dives when needed, and launch visibility—both across our online channels and on stage at Trustless Agents Day (Nov 21, Devconnect Buenos Aires).
What You Get
Technical Guidance
Expert technical support and code reviews from the ERC-8004 team and Ethereum Foundation developers.
Collaborative Review
Product-scope review sessions to help refine your implementation and ensure alignment with the standard.
Weekly Calls
Regular check-ins and group sessions to share progress, ask questions, and learn from other builders.
1:1 Deep Dives
Optional one-on-one sessions for detailed technical discussions and personalized guidance.
Launch Visibility
Showcase your project across our online channels and on stage at Trustless Agents Day.
Reference Examples
Access to canonical contracts, example flows, and best practices for ERC-8004 implementation.
Program Timeline
Program Launch
Builder Program officially begins with orientation and initial project scoping.
Final Specification (v1) Published
Stable specification ready for implementation across all participating teams.
Testnet Deployments
Reference implementations deployed to testnets to support all builders.
Trustless Agents Day @ Devconnect
Showcase your project on stage at the Ethereum Foundation–hosted gathering in Buenos Aires.
Who Should Apply
This program is designed for teams and individuals who are:
- Building agents or agent-related infrastructure
- Interested in implementing ERC-8004 in their projects
- Looking to contribute to the agent discovery and trust ecosystem
- Committed to participating in weekly calls and collaborative sessions
- Ready to showcase their work at Trustless Agents Day
Ready to Build?
Join 80+ builder groups already interested in implementing pilots and integrations with ERC-8004.
Builder Program FAQ
Find answers to common questions about the 8004 Devconnect Builder Program. If you don't see your question answered here, feel free to reach out to our community.
General Questions
What is the 8004 Devconnect Builder Program?
The 8004 Devconnect Builder Program is a focused support program for teams who want to build on ERC-8004. It includes collaborative product-scope review, technical guidance, weekly calls, optional one-to-one deep dives when needed, and launch visibility—both across our online channels and on stage at Trustless Agents Day (Nov 21, Devconnect Buenos Aires).
Who can participate in the Builder Program?
This program is designed for teams and individuals who are building agents or agent-related infrastructure, interested in implementing ERC-8004 in their projects, looking to contribute to the agent discovery and trust ecosystem, committed to participating in weekly calls and collaborative sessions, and ready to showcase their work at Trustless Agents Day.
How long does the program run?
The program runs from September 23 to November 20, 2025, culminating in the Trustless Agents Day showcase on November 21 at Devconnect Buenos Aires.
Application & Selection
How do I apply to the Builder Program?
You can apply through our official application page. Make sure to provide details about your project, team, and how you plan to use ERC-8004.
What is the application deadline?
Applications are accepted on a rolling basis, but we recommend applying early to secure your spot in the program. The program officially begins on September 23, 2025.
How are participants selected?
We evaluate applications based on project alignment with ERC-8004 goals, technical feasibility, team commitment, and potential impact on the agent ecosystem. We aim to support a diverse range of projects and use cases.
Program Structure & Support
What kind of technical support do participants receive?
Participants receive expert technical support and code reviews from the ERC-8004 team and Ethereum Foundation developers, including collaborative product-scope review sessions, weekly group calls, and optional one-on-one deep dives for detailed technical discussions.
Are the weekly calls mandatory?
While we strongly encourage participation in weekly calls to maximize the program's benefits, we understand that schedules can be challenging. We work with participants to find the best arrangement that works for everyone.
What resources are provided to participants?
Participants get access to canonical contracts, example flows, best practices for ERC-8004 implementation, reference examples, and comprehensive documentation. We also provide launch visibility across our online channels.
Timeline & Milestones
What are the key program milestones?
Key milestones include: Program Launch (Sep 23), Final Specification v1 Published (Oct 8), Testnet Deployments (Oct 15), and the culminating Trustless Agents Day showcase (Nov 21).
What happens at Trustless Agents Day?
Trustless Agents Day is an Ethereum Foundation–hosted gathering featuring key opinion leaders from AI and Web3, and live pitches from projects built on ERC-8004. It's your opportunity to showcase your work to the broader community.
Is participation in Trustless Agents Day required?
While showcasing your project at Trustless Agents Day is a key benefit of the program, we understand that not everyone may be able to attend in person. We'll work with participants to find alternative ways to showcase their work.
Technical Questions
Do I need to have a working prototype to apply?
No, you don't need a working prototype to apply. We welcome applications from teams at various stages of development, from early concept to advanced prototypes. The program is designed to help you build and refine your implementation.
What programming languages or frameworks are supported?
ERC-8004 is chain-agnostic within EVM and can be implemented using any programming language that can interact with Ethereum. We support implementations in Solidity, JavaScript/TypeScript, Python, Go, and other languages commonly used in the Ethereum ecosystem.
Can I work on multiple projects during the program?
We recommend focusing on one primary project during the program to maximize the benefits of our support. However, if you have multiple related projects that can be integrated, we're happy to discuss this during the application process.
Community & Networking
How can I connect with other program participants?
Participants can connect through our weekly calls, dedicated Telegram channels, and community events. We also facilitate introductions between participants working on complementary projects.
Is there ongoing support after the program ends?
While the formal program ends in November, we maintain ongoing relationships with participants and continue to provide support through our community channels. Many participants become long-term contributors to the ERC-8004 ecosystem.
Still Have Questions?
If you don't see your question answered here, we're here to help!
Timeline & News
ERC-8004 draft goes public
The initial specification is published and shared with the ecosystem.
Public discussion & 1:1 feedback
Open community review on forums and social channels, plus one-on-one conversations with teams to identify areas for improvement across identity, reputation, and validation.
In parallel — 10+ prototypes
More than ten prototypes are built against the initial draft.
Final specification (v1) published
The v1 spec is frozen for implementation. Note: while off-chain schemas and conventions (e.g., for feedback payloads or agent cards) may be recommended and evolve over time, the on-chain standard itself should remain stable and change only for materially important reasons.
Testnet deployments of reference implementations
Canonical contracts and example flows are deployed to testnets to support implementers.
8004 Builder Program
A focused program to support teams integrating ERC-8004, with office hours, code reviews, and reference examples.
Trustless Agents Day @ Devconnect, Buenos Aires
An Ethereum Foundation–hosted gathering featuring key opinion leaders from AI and Web3, and live pitches from projects built on ERC-8004.