| Internet-Draft | Agent Identity Document | October 2026 |
| Alla | Expires 6 April 2027 | [Page] |
Autonomous software agents increasingly act on the public internet with no name that a counterparty can check, no published party that answers for them, and no way to learn that an operator has withdrawn an agent. This document specifies the Agent Identity Document, a small JSON document served at a well-known URI on a hostname assigned to one agent, and the practices an identity provider follows when it hosts such names for operators who do not run their own domain.¶
The document records what the provider knows to be true (the hostname, its service endpoints and the identity's lifecycle status) separately from what the operator asserts (a description, a contact, a homepage, a public key), and publishes the provider's dated, expiring checks on the operator rather than a single trust level. Lifecycle status is distinct from availability. A suspended identity publishes a deliberately minimal document. Every identity is held by an accountable person or organisation; an agent is never itself an account holder, and agents are never given authority over DNS.¶
This document describes a practice in production at one provider. It is published so that the format can be reviewed, implemented by others and mapped onto related work, and it requests registration of a well-known URI suffix.¶
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 6 April 2027.¶
Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved.¶
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. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
Websites solved a version of this problem years ago. A certificate says who a site is. A published security contact says where to report a problem. A revoked certificate stops being trusted everywhere at once. Software agents that call APIs, serve tools and receive webhooks on the open internet have none of this by default. They borrow their operator's credentials, run from addresses nobody can trace, and carry no name that another system can look up.¶
Several efforts address parts of the gap. The Agent Name Service
[I-D.narajala-courtney-ansv2] anchors an agent to a domain the operator
controls and a certificate hierarchy. The A2A Agent Card [A2A] describes an
agent's capabilities at /.well-known/agent-card.json. The Agent Discovery
Protocol [I-D.pro-adp-agent-discovery] describes discovery metadata.
Web Bot Auth [I-D.ietf-webbotauth-httpsig-protocol] lets an agent sign its
requests with a key a verifier can fetch.¶
Each of these assumes the operator already has something: a domain, a certificate, a key directory. Most people who build agents have none of them, and have no wish to run DNS or PKI. This document describes the missing layer for them: an identity hosted by a provider, created in one request, with the name, TLS, service endpoints and a public record supplied by the provider, and with a person or organisation accountable for it from the first minute.¶
It also records four design positions that distinguish this format from related work:¶
Facts and assertions are kept apart. The provider publishes what it made true (name, endpoints, status) and labels what the operator merely claims.¶
Checks on the operator are itemised, dated and expiring. There is no level and no badge; each check says what was checked, how, by whom, when, and until when.¶
Lifecycle is not liveness. status records the operator's and
provider's decisions about the identity. It never reports whether the
agent is online.¶
A person stays accountable. An identity belongs to an account held by a natural person or legal entity. An agent acts under an account; it is never one. Agents never hold DNS or registrar authority.¶
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, as shown here.¶
The terms "identity provider" and "provider" mean the party that assigns hostnames under a base domain it controls and serves Agent Identity Documents for them. "Operator" means the account holder responsible for an agent. "Relying party" means any system that reads an Agent Identity Document to decide how to treat an agent.¶
The provider controls a base domain. Each identity receives one identity hostname, a single DNS label under the base domain:¶
<slug>.<base-domain> e.g. alice.knownas.dev¶
Each service the identity offers receives a service hostname with the service label leading the base domain, so that every hostname is exactly one label below a name the provider can cover with a wildcard certificate:¶
<slug>.api.<base-domain> an HTTP API <slug>.mcp.<base-domain> a Model Context Protocol endpoint <slug>.hooks.<base-domain> inbound webhooks¶
The nested form api.<slug>.<base-domain> is NOT used: a wildcard
certificate covers exactly one label, and the nested form would require a
certificate per identity.¶
A <slug> MUST be a valid DNS label [RFC1035]: lowercase ASCII letters,
digits and hyphens, not beginning or ending with a hyphen. This specification
RECOMMENDS a minimum of 3 and a maximum of 63 characters. The provider MUST
refuse slugs that collide with its own infrastructure names (such as api,
mcp, hooks, www) and SHOULD refuse names that impersonate protected
brands, including when a brand appears as a word inside a longer slug
("combosquatting"). Refusal lists are the provider's; this document requires
only that they exist and are enforced before any DNS record is written.¶
An identity is created and held by an account. An account MUST be held by a natural person or a legal entity, and the provider MUST verify at minimum that the account holder controls the e-mail address used to create it. The provider MAY require a minimum age.¶
An agent MAY manage identities through a credential scoped to an account, and MAY be the thing that creates an identity. An agent MUST NOT be able to create an account. This keeps a person or organisation answerable for every identity, however it was created.¶
The Agent Identity Document is a JSON document [RFC8259] served over HTTPS [RFC9110] at the well-known URI [RFC8615]¶
https://<identity-hostname>/.well-known/agent-identity.json¶
Implementations that predate this document serve the same content at
/.well-known/agent.json; see Section 5.4.¶
The document MUST be served with Content-Type: application/json,
X-Content-Type-Options: nosniff and Access-Control-Allow-Origin: *, so
that a browser-based relying party can read it. The same headers MUST be sent
on a 404 response for an unallocated or deleted identity, so that a relying
party can distinguish "no such identity" from a network failure.¶
A relying party MUST treat a 404 at this URI as "no identity is published here", and MUST NOT treat it as evidence that the hostname was never allocated: a deleted identity's document is removed before its DNS records are, and a tombstoned name may still resolve to the provider for a time (Section 4).¶
The top level is a JSON object. Members fall into two classes, and the class decides how a relying party may use the value.¶
These are projected by the provider from its own records at render time. They are never writable by the operator; a provider MUST ignore any attempt to set them.¶
version:String. The schema version. This document defines "1". REQUIRED.¶
fqdn:String. The identity hostname. REQUIRED.¶
status:String. The lifecycle status (Section 3.3). REQUIRED.¶
endpoints:Object mapping an endpoint name to an absolute https URL. REQUIRED when
status is not suspended. The provider MUST include web (the identity
hostname) and manifest (this document's URL). It MUST include one member
per service hostname the identity owns, named api, mcp or webhooks
(note: the member is webhooks; its DNS label is hooks). Every value MUST
begin with https://.¶
owner:Object. The provider's published checks on the account holder and the account's standing (Section 3.5). OPTIONAL; absent when the identity is suspended, or when the account is not in good standing.¶
These are supplied by the operator. The provider validates their form and MUST NOT present them as verified unless a check described in Section 3.5 covers them.¶
name:String, at most 120 characters. A display name; defaults to the slug. REQUIRED when not suspended.¶
description:String, at most 500 characters. OPTIONAL.¶
contact:Object with an email member, at most 254 characters. OPTIONAL.¶
homepage:String, an absolute https URL of at most 2048 characters. OPTIONAL.¶
public_key:String, at most 4096 characters. An opaque key the operator publishes. This document assigns it no verification semantics; see Section 5.2. OPTIONAL.¶
metadata:Object of at most 20 members. Keys MUST match
^[a-z0-9][a-z0-9_.-]*$ and be at most 40 characters; values MUST be
strings of at most 200 characters. OPTIONAL.¶
All string values in the document MUST be free of C0 control characters
other than those JSON itself requires to be escaped, and the provider MUST
reject input that contains them. All URLs MUST use the https scheme; a
provider MUST reject http, javascript, data and every other scheme.
The provider MUST NOT dereference any URL an operator supplies.¶
status takes one of the values below. It records decisions, not
reachability.¶
| Value | Meaning |
|---|---|
pending
|
Created; provisioning has not started |
provisioning
|
DNS records are being written |
active
|
Provisioned, and in good standing |
suspended
|
Withdrawn from public view by the operator or the provider; restorable |
failed
|
Provisioning did not complete |
archived
|
Retired by the operator; the name is kept |
deleting
|
Removal in progress; the document disappears shortly |
A relying party MUST NOT infer from active that the agent is reachable or
running, and a provider MUST NOT change status because an agent's own
endpoints went unreachable. An agent that sleeps at night keeps its name.
Availability, if a relying party needs it, is measured by the relying party.¶
When status is suspended, the provider MUST serve exactly:¶
{ "version": "1", "status": "suspended", "fqdn": "alice.knownas.dev" }
¶
No endpoints, no description, no contact, no owner block. The namespace stays allocated and DNS stays in place, so the name cannot be taken by someone else, but nothing the operator wrote continues to be advertised. Suspension is therefore visible to every relying party within the document's cache lifetime, which the provider SHOULD keep short (the reference implementation uses 60 seconds).¶
Suspension of an account MUST stop every credential under it and MUST suspend every identity it holds.¶
The owner member publishes the provider's checks on the account holder.
There is deliberately no level, score or badge. Each check is its own record:¶
"owner": {
"verifications": [
{ "type": "email", "verified_at": "2026-09-21T14:02:11+00:00" },
{
"type": "domain",
"value": "acme.example",
"method": "dns-txt",
"verifier": "knownas.dev",
"verified_at": "2026-10-02T09:00:00+00:00",
"expires_at": "2026-11-01T09:00:00+00:00"
}
],
"standing": { "account_since": "2026-09-21", "status": "active" }
}
¶
Each member of verifications is an object with:¶
type:String. This document defines email (the account holder controlled the
sign-up mailbox) and domain (the account holder controls a DNS name).
Further types, such as a check on a legal entity or a natural person, MAY
be defined; a relying party MUST ignore types it does not understand.¶
verified_at:value:String. What was checked, where that is public (a domain name). For
email the address itself MUST NOT be published. OPTIONAL.¶
method, verifier:Strings naming how and by whom the check was made. OPTIONAL.¶
expires_at:String, an [RFC3339] timestamp after which the check MUST be treated as stale. OPTIONAL; a check without it does not expire.¶
standing carries account_since (an [RFC3339] full-date) and status,
which is active whenever the block is present; a provider MUST omit the
whole owner block rather than publish any other standing.¶
Relying parties MUST interpret checks by type and date. The absence of a check is the absence of information and MUST NOT be presented as a negative finding; many legitimate operators cannot or will not complete deeper checks. Human-facing presentations SHOULD say what was checked ("owner controls acme.example") and SHOULD NOT say "verified" or "trusted" without an object.¶
A document is only as good as the namespace behind it. A provider that serves Agent Identity Documents:¶
Writes explicit DNS records, never a wildcard. An unallocated name
MUST return NXDOMAIN. A wildcard would make paypal.<base-domain>
resolve.¶
Restricts certificate issuance for the base domain with CAA [RFC8659] to the authority it uses, so that no one else can obtain a certificate for a hosted name.¶
Removes the document before the DNS records when an identity is deleted, and changes only the document on suspension. Everything the public can read goes through the document; only reachability goes through DNS, and DNS removal may be slow.¶
Tombstones released names for a cooling period (the reference implementation uses 30 days) during which no new account may take the name, while the previous holder may reclaim it at once. A leftover record during that period points only at the provider, which answers 404.¶
Keeps an append-only audit trail of every change to every identity, recording whether a person or an agent made it. The application that serves the API MUST NOT be able to alter or delete entries.¶
Enforces quotas on identities per account and per day, and on failure SHOULD suspend rather than bill.¶
An A2A card at /.well-known/agent-card.json [A2A] declares that a URL
speaks A2A over a stated binding. A provider MUST NOT generate a card from
the Agent Identity Document alone, because it does not know what the
operator's server speaks. A provider MAY serve a card the operator declares,
beside this document, and when it does the endpoints object SHOULD carry
an agent_card member pointing to it. A suspended identity MUST serve no
card.¶
Where an agent signs its requests with HTTP Message Signatures [RFC9421] as
profiled by Web Bot Auth [I-D.ietf-webbotauth-httpsig-protocol], the natural
Signature-Agent value is the identity hostname as an https origin, and
the key directory is served by the provider at
/.well-known/http-message-signatures-directory on that origin. A verifier
that resolves the signature then already knows where the Agent Identity
Document is. The public_key member of this document is unrelated to that
directory and carries no verification semantics of its own.¶
ANS [I-D.narajala-courtney-ansv2] and similar work anchor an agent to a
domain the operator controls. This document is complementary: a hosted
identity is for operators who have no domain, and an operator who later
proves control of a domain publishes that as a domain check in the owner
block. Nothing here prevents a provider from also issuing ANS records.¶
The reference implementation has served this document at
/.well-known/agent.json since 2026. That path was also used by A2A before
its version 0.3.0 and has been proposed for other formats. Providers
SHOULD serve this document at /.well-known/agent-identity.json and MAY
continue to serve it at /.well-known/agent.json during a transition; a
relying party SHOULD try the former first.¶
Operator-asserted members are claims. A relying party MUST NOT treat
contact, homepage, description, public_key or metadata as verified
because they are served over HTTPS from the provider's domain. Only the
checks in owner are the provider's statements, and each is bounded by its
dates.¶
The provider is a trust anchor. A hosted identity is only as trustworthy as the provider's own controls: who may create accounts, how names are policed, how suspension is applied, and whether the audit trail can be altered. Section 4 lists the minimum. Relying parties SHOULD form a view of a provider as they do of a certificate authority.¶
Caching bounds suspension. A relying party that caches the document for
longer than the provider's Cache-Control may keep trusting a suspended
identity. Providers SHOULD keep the lifetime short; relying parties making
consequential decisions SHOULD re-fetch at decision time.¶
The document is a surface for injection. It is operator-controlled
content served from a provider hostname. Length caps, control-character
rejection and the https-only rule exist so that a document cannot carry a
javascript: link or terminal escape into a relying party's logs or UI.
Relying parties MUST still treat every string as untrusted data.¶
Identity is not intent. A deliberately malicious operator can decline to identify an agent at all. This format changes the default for responsible operators and makes anonymous agent traffic stand out; it does not stop an attacker.¶
The document publishes: a hostname, endpoints, a status, the operator's
chosen descriptive text, and the provider's checks. For an email check the
address is not published, only that a check occurred and when. For a
domain check the domain name is published, since control of a public name
is itself public. account_since reveals when the account was created and
nothing else about the holder. A provider MUST let an account holder export
and erase their data, and MUST remove an identity's document promptly on
deletion; what the append-only audit trail retains is the provider's
documented retention decision.¶
IANA is requested to register the following well-known URI suffix in the "Well-Known URIs" registry [RFC8615]:¶
An active identity with two services and a verified domain:¶
{
"version": "1",
"name": "Ada",
"status": "active",
"fqdn": "ada.knownas.dev",
"endpoints": {
"web": "https://ada.knownas.dev",
"manifest": "https://ada.knownas.dev/.well-known/agent-identity.json",
"api": "https://ada.api.knownas.dev",
"mcp": "https://ada.mcp.knownas.dev"
},
"description": "Answers questions about the Acme product catalogue.",
"owner": {
"verifications": [
{ "type": "email", "verified_at": "2026-09-21T14:02:11+00:00" },
{ "type": "domain", "value": "acme.example", "method": "dns-txt",
"verifier": "knownas.dev",
"verified_at": "2026-10-02T09:00:00+00:00",
"expires_at": "2026-11-01T09:00:00+00:00" }
],
"standing": { "account_since": "2026-09-21", "status": "active" }
},
"contact": { "email": "agents@acme.example" },
"homepage": "https://acme.example/ada",
"metadata": { "framework": "langgraph" }
}
¶
The same identity, suspended:¶
{ "version": "1", "status": "suspended", "fqdn": "ada.knownas.dev" }
¶
The hostnames are the reference implementation's real base domain rather than the reserved example domains of RFC 2606, because the document describes a practice in production there.¶
The design positions here were worked out as architecture decision records for the reference implementation [KNOWNAS] between September and October 2026. The author thanks the people who tested early versions.¶