# @agentcommunity/aid-doctor

# Agent Identity & Discovery

> DNS for agents

AID as the public address book for the agentic web.

It's a simple, open standard that uses the internet's own directory—DNS—to answer one question: **"Given a domain, where is its AI agent, and how do I know it's the real one?"**

No more hunting through API docs. No more manual configuration. It's the zero-friction layer for a world of interconnected agents.

Built by the team at [agentcommunity.org](https://agentcommunity.org).

- **Website**: [aid.agentcommunity.org](https://aid.agentcommunity.org)
- **Docs**: [docs.agentcommunity.org/aid](https://docs.agentcommunity.org/aid)
- **GitHub**: [github.com/agent-community/agent-identity-discovery](https://github.com/agent-community/agent-identity-discovery)

---

## Install

```bash
npm install -g @agentcommunity/aid-doctor
# or
pnpm add -D @agentcommunity/aid-doctor
```

## Usage

```bash
# Human-readable check
aid-doctor check example.com

# JSON output (machine-readable)
aid-doctor json example.com
```

### Options

- `--protocol <proto>`: record a protocol hint for diagnostics. Checks remain base-first at `_agent.<domain>`.
- `--probe-proto-subdomain` (check): if base TXT lookup fails and `--protocol` is set, probe `_agent._<proto>.<domain>` for diagnostics.
- `--probe-proto-even-if-base` (check): if base TXT lookup succeeds and `--protocol` is set, also probe `_agent._<proto>.<domain>` for drift diagnostics.
- `--timeout <ms>`: DNS query timeout (default: 5000)
- `--no-fallback`: disable `.well-known` fallback on DNS miss
- `--fallback-timeout <ms>`: HTTP timeout for `.well-known` (default: 2000)
- `--security-mode <mode>`: enterprise preset (`balanced` or `strict`)
- `--dnssec <policy>`: DNSSEC policy (`off`, `prefer`, `require`)
- `--pka-policy <policy>`: PKA policy (`if-present`, `require`)
- `--downgrade-policy <policy>`: downgrade policy (`off`, `warn`, `fail`)
- `--well-known-policy <policy>`: `.well-known` policy (`auto`, `disable`)
- `--show-details`: include fallback usage and PKA status in output
- `--code` (check): exit with specific error code on failure

### Exit codes

- `0` success
- `1000` `ERR_NO_RECORD`
- `1001` `ERR_INVALID_TXT`
- `1002` `ERR_UNSUPPORTED_PROTO`
- `1003` `ERR_SECURITY`
- `1004` `ERR_DNS_LOOKUP_FAILED`
- `1` unknown error

## Generate an AID record

```bash
aid-doctor generate
```

Interactive prompts help you craft a valid TXT value for `_agent.<domain>`.

## Examples

```bash
# Check with protocol hint, still base-first
aid-doctor check example.com --protocol mcp

# Probe the protocol-specific underscore name for diagnostics
aid-doctor check example.com --protocol mcp --probe-proto-subdomain

# JSON for CI
aid-doctor json example.com > result.json

# Show PKA/fallback details (v2-aware)
aid-doctor check example.com --show-details

# Enterprise preset with downgrade cache
aid-doctor check example.com --security-mode strict --check-downgrade

# Local testing with a mock HTTP server (insecure well-known)
# (Use only for local dev)
AID_ALLOW_INSECURE_WELL_KNOWN=1 aid-doctor check localhost:19081 --show-details --fallback-timeout 2000
```

### PKA handshake expectations

- AID v2 `k`/`pka` is the unpadded base64url JWK `x` value for the raw 32-byte Ed25519 public key
- v2 reports derive the HTTP Message Signature `keyid` as the RFC 7638 JWK SHA-256 thumbprint
- `alg` must be `ed25519`
- v2 PKA uses a nonce-bound HTTP Message Signature response and requires `Cache-Control: no-store`
- v2 PKA sends the queried host in the `AID-Domain` header by default and reports a `domainBound` indicator (`true` only for a verified domain-bound proof — one whose `aid-pka-v2` covered set includes `"aid-domain";req`). Requesting binding does not by itself mitigate unauthorized association — only `domain-binding=require` enforces it. See specification Appendix B.7.
- Legacy `aid1` records can still be checked during the compatibility window, including their legacy `kid`

### Loopback HTTP (dev‑only)

When `AID_ALLOW_INSECURE_WELL_KNOWN=1` is set and the domain is loopback (`localhost`/`127.0.0.1`/`::1`), the doctor permits `http://` in the `.well-known` path for local testing. All other validations, including PKA, still run. TXT discovery always enforces `https://` for remote agents.

## License

MIT © [Agent Community](https://agentcommunity.org)