langchain-dns-aid 0.1.0

DNS-AID agent discovery middleware for LangChain

langchain-dns-aid

DNS-AID agent discovery middleware for LangChain. Enables agents to discover, publish, and unpublish themselves via DNS using the DNS-AID protocol.

Why middleware instead of tools?

Unlike tool-only integrations (CrewAI, LlamaIndex, etc.), the middleware approach uses LangChain's lifecycle hooks to auto-publish the agent on startup and auto-unpublish on shutdown. This prevents stale DNS records when agents crash or forget to clean up.

Install

pip install langchain-dns-aid

Quick start

from langchain import create_agent, init_chat_model
from langchain_dns_aid import DnsAidMiddleware

agent = create_agent(
    model=init_chat_model("gpt-4o"),
    middleware=[DnsAidMiddleware(
        agent_name="my-assistant",
        domain="agents.example.com",
        endpoint="assistant.example.com",
        capabilities=["code-review", "documentation"],
        backend_name="route53",
    )],
)

# Agent is auto-published to DNS on startup.
# It can discover other agents during conversation.
# On shutdown, it is auto-unpublished.

What it does

Hook	Action
before_agent	Auto-publishes the agent to DNS via SVCB records
after_agent	Auto-unpublishes the agent, removing DNS records
Tools	dns_aid_discover, dns_aid_publish, dns_aid_unpublish

Configuration

Parameter	Default	Description
agent_name	None	Agent DNS label (required for auto-publish)
domain	None	Domain to publish under (required for auto-publish)
protocol	"mcp"	Protocol: mcp, a2a, or https
endpoint	""	Hostname where agent is reachable
port	443	Port number
capabilities	None	List of agent capabilities
backend_name	None	DNS backend: route53, cloudflare, mock, etc.
auto_publish	True	Auto-publish on agent start
auto_unpublish	True	Auto-unpublish on agent stop

Discovery only (no auto-publish)

agent = create_agent(
    model=init_chat_model("gpt-4o"),
    middleware=[DnsAidMiddleware(
        auto_publish=False,
        auto_unpublish=False,
    )],
)
# Agent gets dns_aid_discover tool but doesn't publish itself.

License

Apache-2.0