Allow overriding the provider preset with an explicit HTTPS DoH URL, including validation that custom endpoints apply only to DoH queries.
Encrypted DNS Skill
An Agent Skill and deterministic Go CLI for querying and diagnosing encrypted DNS resolvers.
The skill tells an agent when and how to perform encrypted DNS diagnostics;
ednsdiag performs the protocol exchange. Agents do not need to construct DoH
URLs, TLS sessions, or DNS wire messages themselves.
Status
| Protocol | Status | Standard |
|---|---|---|
| DNS over HTTPS (DoH) | Available (GET and POST) | RFC 8484 |
| DNS over TLS (DoT) | Available (strict authentication) | RFC 7858, RFC 8310 |
| DNS over QUIC (DoQ) | Planned | RFC 9250 |
| DoH over HTTP/3 (DoH3) | Planned | RFC 8484 over HTTP/3 |
| DNSCrypt | Planned | DNSCrypt protocol specification |
| Oblivious DoH (ODoH) | Research | RFC 9230 |
| Anonymized DNSCrypt | Research | Anonymized DNSCrypt specification |
Run ednsdiag capabilities instead of assuming a protocol is implemented.
Why a Skill and a CLI?
SKILL.mdprovides compact instructions, safety boundaries, and result interpretation for an AI agent.ednsdiagprovides repeatable wire-format DNS, HTTP, TLS, input validation, and structured JSON output.- Reference files keep protocol, provider, and security details grounded in authoritative sources without bloating the agent's active context.
The CLI never silently downgrades to plaintext DNS, and it does not connect to addresses returned in DNS answers.
Requirements
- Go 1.26 or later when running or building from source
- Network access to the selected encrypted DNS resolver
- A host that supports the Agent Skills package format when using the repository as a Skill
Install the Skill
Clone or copy this repository into a skill discovery directory supported by
your agent host. Keep the repository layout intact so SKILL.md, references/,
schemas/, and the Go source remain together.
For example, in a host that discovers project-local skills from .agents/skills:
git clone https://github.com/windyboy/encrypted-dns-skill.git \
.agents/skills/encrypted-dns-skill
Discovery paths differ between hosts. Follow the host's documentation rather
than moving only SKILL.md.
Run from Source
No precompiled executable is required. Go can compile and run the command from the repository root:
go run ./cmd/ednsdiag capabilities
go run ./cmd/ednsdiag query example.com A --protocol doh --provider cloudflare
go run ./cmd/ednsdiag query gmail.com MX --protocol dot --provider google --timeout 5s
The first run may download the modules pinned in go.mod and go.sum.
To build a reusable local executable:
go build -o ./bin/ednsdiag ./cmd/ednsdiag
./bin/ednsdiag capabilities
Do not download or execute an unverified third-party binary. This repository does not currently publish release binaries.
Usage
ednsdiag capabilities
ednsdiag version
ednsdiag query <domain> [type] \
[--protocol doh|dot] \
[--provider cloudflare|google|quad9|adguard] \
[--method post|get] \
[--timeout 5s]
Defaults are A, doh, cloudflare, post, and 5s. --method applies
only to DoH. The timeout must be between 250ms and 30s.
Built-in resolver profiles:
| Provider | Profile |
|---|---|
| Cloudflare | Unfiltered |
| Unfiltered | |
| Quad9 | Security-filtered |
| AdGuard | Ad- and security-filtered |
Filtering policies can affect DNS answers. Results always identify the provider and profile used.
Result Semantics
Every query returns structured JSON compatible with
schemas/result-v1.schema.json.
completed: truemeans the encrypted protocol exchange completed; it does not mean the DNS response wasNOERROR.dns.rcodeis the DNS result.NXDOMAIN,SERVFAIL, andREFUSEDare DNS outcomes, not transport failures.- Empty
dns.answerswithNOERRORmeans NODATA. transport.server_authenticatedreports resolver endpoint authentication.dns.resolver_reports_dnssec_authenticatedreflects the resolver's AD bit; it is not local DNSSEC validation.transport.bootstrap: system_resolvermeans the operating system resolver was used to locate the encrypted resolver endpoint.
Security Model
- DoH uses standard
application/dns-messagewire messages. - DoT verifies the PKIX certificate chain and configured authentication domain.
- Plaintext fallback is prohibited.
- DNS errors are not retried through another protocol as transport failures.
- Provider and protocol results remain separate.
- DNS answers are data only; the tool does not make application connections to returned addresses.
See references/security.md for the complete threat
model and privacy boundaries.
Development
go test ./...
go vet ./...
Protocol behavior must remain aligned with
references/standards.md, provider changes with
references/providers.md, and output with the v1
JSON schema.
Scope
This project targets client-to-recursive encrypted DNS diagnostics. It is not a system stub resolver, an authoritative DNS server, a hosted DNS record manager, or a zone-transfer tool.
License
Licensed under the Apache License 2.0.