AGTP Web3 Bridge Specification
draft-hood-agtp-web3-bridge-00
This document is an Internet-Draft (I-D).
Anyone may submit an I-D to the IETF.
This I-D is not endorsed by the IETF and has no formal standing in the
IETF standards process.
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Author | Chris Hood | ||
| Last updated | 2026-03-23 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-hood-agtp-web3-bridge-00
Independent Submission C. Hood
Internet-Draft Nomotic, Inc.
Intended status: Informational 23 March 2026
Expires: 24 September 2026
AGTP Web3 Bridge Specification
draft-hood-agtp-web3-bridge-00
Abstract
The Agent Transfer Protocol (AGTP) uses a PKI-based trust model:
agent identity is anchored to DNS-verified domain ownership and CA-
issued X.509 certificates. Web3 systems offer an alternative
identity model based on blockchain address ownership, smart contract
verification, and decentralized naming systems including the Ethereum
Name Service (ENS) and Unstoppable Domains. This document specifies
the AGTP Web3 Bridge: a framework for mapping Web3 identity anchors
to AGTP trust tiers, resolving Web3 names to canonical AGTP Agent-
IDs, and operating AGTP sessions with agents whose identity is
anchored to blockchain rather than DNS. Web3-anchored agents are
treated as Trust Tier 2 (Org-Asserted) in the absence of additional
verification. This document also defines the conditions under which
a Web3 identity MAY be elevated to Trust Tier 1 through a hybrid
verification procedure.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 24 September 2026.
Copyright Notice
Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved.
Hood Expires 24 September 2026 [Page 1]
Internet-Draft AGTP-WEB3 March 2026
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Two Identity Models . . . . . . . . . . . . . . . . . . . 2
1.2. Scope and Status . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Web3 Identity Anchors and AGTP Trust Tiers . . . . . . . . . 4
3.1. Default Trust Tier Assignment . . . . . . . . . . . . . . 4
3.2. Trust Tier 1 Elevation for Web3 Agents . . . . . . . . . 5
4. Name Resolution . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. ENS Resolution . . . . . . . . . . . . . . . . . . . . . 5
4.2. Unstoppable Domains Resolution . . . . . . . . . . . . . 6
4.3. DID Resolution . . . . . . . . . . . . . . . . . . . . . 6
5. Operating AGTP Sessions with Web3-Anchored Agents . . . . . . 7
5.1. Session Establishment . . . . . . . . . . . . . . . . . . 7
5.2. Authority-Scope Constraints . . . . . . . . . . . . . . . 7
5.3. Governance Token Compatibility . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
6.1. Blockchain Reorganization . . . . . . . . . . . . . . . . 8
6.2. ENS Name Expiry . . . . . . . . . . . . . . . . . . . . . 8
6.3. Private Key Compromise . . . . . . . . . . . . . . . . . 8
6.4. Smart Contract Vulnerabilities . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Web3 Ecosystem Status Note . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
1.1. Two Identity Models
AGTP's default trust model is PKI-based. An agent's identity is
anchored to a real-world domain (e.g., acme.tld), verified through
DNS ownership challenge per, and bound to a CA-signed certificate
chain. This model inherits decades of web PKI infrastructure and
integrates cleanly with enterprise certificate management systems.
Web3 systems provide a different identity model. In Web3, identity
is anchored to a blockchain address: a cryptographic key pair whose
public address is a first-class identifier. Ownership of a
Hood Expires 24 September 2026 [Page 2]
Internet-Draft AGTP-WEB3 March 2026
blockchain address is proven by signing a challenge with the
corresponding private key. Web3 naming systems (ENS, Unstoppable
Domains) map human-readable names to blockchain addresses, analogous
to DNS mapping names to IP addresses.
These models are not mutually exclusive. An organization may hold
both a verified DNS domain and blockchain-anchored assets. An agent
may legitimately derive its identity from either model. AGTP must
interoperate with both.
1.2. Scope and Status
This document is informational. The Web3 ecosystem is evolving
rapidly, and a fully normative specification would risk premature
standardization of mechanisms that have not stabilized. This
document defines:
* The resolution_layer field values for Web3 identity anchors
(already defined in [AGTP] Section 6.6)
* Mapping rules from Web3 identity to AGTP Trust Tiers
* Name resolution procedures for ENS and Unstoppable Domains
* A hybrid verification procedure for Trust Tier 1 elevation
* Security considerations specific to Web3-anchored agents
Implementers *MAY* use this document as guidance. A future normative
revision will be issued as the Web3 identity landscape stabilizes.
2. Terminology
The key words "*MUST*", "*MUST NOT*", "*REQUIRED*", "*SHALL*",
"*SHALL NOT*", "*SHOULD*", "*SHOULD NOT*", "*RECOMMENDED*", "*NOT
RECOMMENDED*", "*MAY*", and "*OPTIONAL*" in this document are to be
interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only
when, they appear in all capitals.
Blockchain Address: A cryptographic public key hash serving as a
first-class identifier on a blockchain network (e.g., an Ethereum
address of the form 0x... or a Solana address in base58 encoding).
ENS (Ethereum Name Service): A distributed naming system built on
the Ethereum blockchain that maps human-readable names (e.g.,
acme.eth) to Ethereum addresses and other records. Defined in
[EIP-137].
Hood Expires 24 September 2026 [Page 3]
Internet-Draft AGTP-WEB3 March 2026
Unstoppable Domains: A blockchain-based naming system providing
human-readable domain names (e.g., acme.crypto, acme.nft) anchored
to blockchain addresses.
DID (Decentralized Identifier): A globally unique identifier defined
by [W3C-DID] that enables verifiable, decentralized digital
identity without dependence on a centralized registry.
Web3 Trust Anchor: A blockchain address, ENS name, Unstoppable
Domain name, or DID that serves as the primary identity anchor for
a Web3-registered agent.
3. Web3 Identity Anchors and AGTP Trust Tiers
3.1. Default Trust Tier Assignment
[AGTP] Section 6.6 defines the resolution_layer field in the Agent
Manifest Document and specifies that Web3-anchored agents *MUST* be
treated as Trust Tier 2 (Org-Asserted) in the absence of additional
verification:
+==================+===================+=====================+
| resolution_layer | Default Trust | Notes |
| Value | Tier | |
+==================+===================+=====================+
| dns | Tier 1 (if DNS | Standard AGTP |
| | challenge passed) | default |
+------------------+-------------------+---------------------+
| pki | Tier 2 | PKI without DNS |
| | | challenge |
+------------------+-------------------+---------------------+
| web3-ens | Tier 2 | ENS name ownership |
| | | verified |
+------------------+-------------------+---------------------+
| web3-unstoppable | Tier 2 | Unstoppable Domains |
| | | ownership verified |
+------------------+-------------------+---------------------+
| web3-did | Tier 2 | DID method-specific |
| | | verification |
+------------------+-------------------+---------------------+
| agtp-registry | Tier 2 | Direct registry |
| | | registration, no |
| | | domain anchor |
+------------------+-------------------+---------------------+
Table 1: resolution_layer Values and Default Trust Tiers
Hood Expires 24 September 2026 [Page 4]
Internet-Draft AGTP-WEB3 March 2026
Trust Tier 2 means the agent's identity is asserted and verifiable
(ownership of the blockchain address is provable) but the agent has
not been verified as representing a specific real-world organization
through DNS. The trust_warning: "org-label-unverified" field *MUST*
appear in the Agent Manifest Document for all Web3-anchored agents at
default Trust Tier 2.
3.2. Trust Tier 1 Elevation for Web3 Agents
A Web3-anchored agent *MAY* be elevated to Trust Tier 1 through a
hybrid verification procedure that combines blockchain address
ownership proof with DNS ownership verification:
1. The agent operator proves ownership of the blockchain address by
signing an AGTP-issued challenge with the corresponding private
key.
2. The agent operator publishes a DNS TXT record at
_agtp.[domain.tld] containing the blockchain address:
_agtp.acme.tld. IN TXT "agtp-web3=0x1a2b3c...; chain=ethereum"
1. The AGTP governance platform verifies both the blockchain
signature and the DNS TXT record.
2. On successful dual verification, the agent is registered at Trust
Tier 1 with resolution_layer: web3-ens (or equivalent) and the
DNS anchor recorded in the Agent Manifest Document.
This hybrid procedure establishes that the same entity controls both
the blockchain address and the DNS domain, providing a trust level
equivalent to standard DNS-anchored verification.
4. Name Resolution
4.1. ENS Resolution
ENS names (e.g., acme.eth) resolve to Ethereum addresses through the
ENS registry smart contract. AGTP implementations that support ENS
resolution *MUST*:
1. Query the ENS registry contract for the address record associated
with the ENS name.
2. Verify that the resolved address matches the blockchain_address
field in the agent's registration record.
Hood Expires 24 September 2026 [Page 5]
Internet-Draft AGTP-WEB3 March 2026
3. Verify that the agent's canonical Agent-ID is recorded in the ENS
name's text records under the key agtp-agent-id.
ENS text record format:
Key: agtp-agent-id
Value: 3a9f2c1d8b7e4a6f...
AGTP resolution *MUST* treat the ENS text record as informational
only. The canonical Agent-ID in the AGTP registry is authoritative.
If the ENS text record conflicts with the AGTP registry, the AGTP
registry value *MUST* be used.
4.2. Unstoppable Domains Resolution
Unstoppable Domains names resolve through a blockchain registry
contract specific to each domain extension (.crypto, .nft, .x, etc.).
AGTP implementations that support Unstoppable Domains resolution
*MUST* follow the same verification procedure as ENS, adapted for the
specific registry contract of the domain extension.
Unstoppable Domains record format:
Key: agent.agtp.id
Value: 3a9f2c1d8b7e4a6f...
4.3. DID Resolution
W3C Decentralized Identifiers [W3C-DID] provide a method-agnostic
framework for decentralized identity. AGTP implementations that
support DID resolution *MUST*:
1. Resolve the DID Document using the DID method-specific resolver.
2. Extract the AGTP-specific service endpoint from the DID Document:
{
"service": [
{
"id": "#agtp",
"type": "AgentTransferProtocol",
"serviceEndpoint": "agtp://agtp.acme.tld/agents/my-agent",
"agtp_agent_id": "3a9f2c1d8b7e4a6f..."
}
]
}
Hood Expires 24 September 2026 [Page 6]
Internet-Draft AGTP-WEB3 March 2026
1. Resolve the serviceEndpoint URI to the agent's canonical AGTP
Agent Manifest Document.
2. Verify that the agtp_agent_id in the DID Document matches the
canonical_id in the Agent Manifest Document.
5. Operating AGTP Sessions with Web3-Anchored Agents
5.1. Session Establishment
AGTP sessions with Web3-anchored agents follow the standard AGTP
session model defined in [AGTP]. The resolution_layer field in the
Agent Manifest Document declares the trust anchor type; the
requesting agent *MUST* retrieve and verify the manifest before
establishing a session.
If the requesting agent requires Trust Tier 1 (e.g., for financial
transactions or cross-organization delegation), it *MUST* reject
connection attempts from Tier 2 Web3-anchored agents unless the
hybrid verification described in Section 3.2 has been completed and
is reflected in the agent's Trust Tier.
5.2. Authority-Scope Constraints
Web3-anchored agents at Trust Tier 2 *MUST NOT* be granted authority
scopes above documents:query and knowledge:query without AGTP-CERT
cryptographic identity binding per [AGTP-CERT], as specified in
[AGTP] Section 6.1.6.
AGTP-CERT binding for Web3-anchored agents follows the same
certificate issuance process as for DNS-anchored agents, with the
blockchain address ownership proof substituted for or supplemented by
the DNS challenge.
5.3. Governance Token Compatibility
Governance Tokens issued for Web3-anchored agents follow the standard
Governance Token format defined in [AGTP] Section 6.7.7. The
agent_id field in the Governance Token *MUST* match the agent's
canonical AGTP Agent-ID (the 256-bit hash form), not the blockchain
address or Web3 name.
6. Security Considerations
Hood Expires 24 September 2026 [Page 7]
Internet-Draft AGTP-WEB3 March 2026
6.1. Blockchain Reorganization
Blockchain networks are subject to reorganization events in which
recently confirmed transactions may be reversed. In AGTP context, a
blockchain reorganization could theoretically reverse the publication
of an ENS text record or Unstoppable Domains record used in agent
verification.
Mitigation: AGTP implementations *SHOULD* require a minimum
confirmation depth before treating blockchain-based verification as
complete. The recommended minimum is 12 blocks for Ethereum mainnet.
Implementations operating on proof-of-stake networks with finality
guarantees *MAY* use the finality checkpoint instead of a block depth
threshold.
6.2. ENS Name Expiry
ENS names require periodic renewal. If an ENS name expires and is
acquired by a different party, the new owner could publish an AGTP
agent ID that points to an agent the original owner registered.
Mitigation: AGTP governance platforms *MUST* monitor ENS name expiry
for all registered Web3-anchored agents and treat an expired ENS name
as equivalent to an expired DNS domain per [AGTP] Section 9.6.
Agents under an expired ENS name *MUST* be automatically Suspended.
6.3. Private Key Compromise
A blockchain address is only as secure as its private key. Private
key compromise grants an attacker the ability to prove ownership of
the address and potentially re-register agents or modify ENS records.
Mitigation: Web3-anchored agent operators *SHOULD* use hardware
wallets or multi-signature schemes for blockchain addresses used in
AGTP registration. Private key rotation *MUST* trigger immediate
agent re-registration with the new address and *MUST* be logged in
the governance audit trail.
6.4. Smart Contract Vulnerabilities
ENS and Unstoppable Domains registry contracts are smart contracts.
Smart contract vulnerabilities could allow attackers to modify name
resolution records without controlling the associated private key.
Hood Expires 24 September 2026 [Page 8]
Internet-Draft AGTP-WEB3 March 2026
Mitigation: AGTP implementations *SHOULD* monitor the security status
of registry contracts they rely on and be prepared to treat affected
resolutions as untrusted pending contract remediation. This document
does not specify a normative procedure for contract vulnerability
response; that is governed by the respective naming system's security
policies.
7. IANA Considerations
This document defines no new IANA registrations. The
resolution_layer field values web3-ens, web3-unstoppable, and
web3-did are defined in [AGTP] Section 6.6.2 and do not require
separate registration.
The DNS TXT record key agtp-web3 used in hybrid verification is a
conventional identifier within the _agtp subdomain established by
[AGTP] Section 6.1.6. No formal IANA registration is required for
this key.
8. References
8.1. Normative References
[AGTP] Hood, C., "Agent Transfer Protocol (AGTP)", Work in
Progress, Internet-Draft, draft-hood-independent-agtp-02,
2026, <https://datatracker.ietf.org/doc/html/draft-hood-
independent-agtp-02>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
8.2. Informative References
[AGTP-CERT]
Hood, C., "AGTP Agent Certificate Extension", Work in
Progress, Internet-Draft, draft-hood-agtp-agent-cert-00,
2026, <https://datatracker.ietf.org/doc/html/draft-hood-
agtp-agent-cert-00>.
[EIP-137] Ethereum Foundation, "Ethereum Name Service", 2016,
<https://eips.ethereum.org/EIPS/eip-137>.
Hood Expires 24 September 2026 [Page 9]
Internet-Draft AGTP-WEB3 March 2026
[W3C-DID] W3C, "Decentralized Identifiers (DIDs) v1.0", 2022,
<https://www.w3.org/TR/did-core/>.
Appendix A. Web3 Ecosystem Status Note
The Web3 identity landscape is evolving rapidly. ENS and Unstoppable
Domains are the most widely deployed blockchain naming systems at the
time of this writing, but the field is not settled. W3C DIDs provide
a method-agnostic framework that may become the preferred abstraction
layer for decentralized identity in agent systems.
This document is intentionally informational to avoid premature
normative commitment. Implementers should treat the procedures in
this document as best-current-practice guidance subject to revision
as the Web3 ecosystem stabilizes.
Author's Address
Chris Hood
Nomotic, Inc.
Email: chris@nomotic.ai
URI: https://nomotic.ai
Hood Expires 24 September 2026 [Page 10]