agent-identity-protocol 0.2.0

Verifiable cryptographic identity and delegation for AI agents across MCP and A2A

Agent Identity Protocol (AIP)

Add identity and auth to AI agents in 5 lines of code.

The problem

MCP has no authentication. A2A has self-declared identities with no attestation. Your agents call tools anonymously, delegate to other agents without verification, and leave no audit trail. When something goes wrong, you have no way to trace who authorized what.

The fix

pip install aip-agents[crewai]

from aip_agents.adapters.crewai import CrewAIPlugin

plugin = CrewAIPlugin(app_name="my-app")
plugin.setup(crew)  # every agent gets a cryptographic identity
headers = plugin.get_auth_headers("researcher")  # signed token for tool calls

That's it. Every agent now has an Ed25519 identity, scoped delegation tokens, and MCP-compatible auth headers.

Google ADK

pip install aip-agents[adk]

from aip_agents.adapters.adk import ADKPlugin

plugin = ADKPlugin(app_name="my-app")
plugin.setup(root_agent)  # walks the agent tree, assigns identities
headers = plugin.get_auth_headers("specialist")

LangChain

pip install aip-agents[langchain]

from aip_agents.adapters.langchain import LangChainPlugin

plugin = LangChainPlugin(app_name="my-app")
plugin.register(executor, name="researcher")
headers = plugin.get_auth_headers("researcher")

What this gives you

• Cryptographic identity -- every agent gets an Ed25519 keypair and an AIP identifier
• Scoped delegation -- when agents delegate, each hop can only narrow scope, never widen
• MCP auth headers -- signed X-AIP-Token headers that any MCP server can verify
• Audit trail -- every token records who authorized what, through which agents, with what scope
• Two token modes -- compact (JWT) for single-hop, chained (Biscuit) for multi-agent delegation

Multi-agent delegation

When agents delegate to other agents, each hop cryptographically narrows scope:

from aip_core.crypto import KeyPair
from aip_token.chained import ChainedToken

root_kp = KeyPair.generate()

# Orchestrator: broad authority
token = ChainedToken.create_authority(
    issuer="aip:web:myorg.com/orchestrator",
    scopes=["tool:search", "tool:email"],
    budget_cents=500,
    max_depth=3,
    ttl_seconds=3600,
    keypair=root_kp,
)

# Delegate to specialist: only search, lower budget
delegated = token.delegate(
    delegator="aip:web:myorg.com/orchestrator",
    delegate="aip:web:myorg.com/specialist",
    scopes=["tool:search"],
    budget_cents=100,
    context="research task for user query",
)

# Specialist can search, but not email
delegated.authorize("tool:search", root_kp.public_key_bytes())  # passes
delegated.authorize("tool:email", root_kp.public_key_bytes())   # raises

MCP Auth Proxy

Protect any MCP server with one command:

pip install agent-identity-protocol
aip-proxy --upstream http://localhost:3000 --port 8080 --trust-key z6Mkf...

The proxy verifies every request's AIP token, runs a security self-audit (TTL, scope, budget, chain depth), and forwards to your MCP server. Rejects anything unauthorized. Zero changes to your server code.

MCP proxy guide | Security model

Installation

# Core library (if building directly on the protocol)
pip install agent-identity-protocol

# Framework adapters (recommended)
pip install aip-agents[crewai]    # CrewAI
pip install aip-agents[adk]       # Google ADK
pip install aip-agents[langchain] # LangChain
pip install aip-agents[all]       # all frameworks

PyPI: agent-identity-protocol | aip-agents

Rust reference implementation available in rust/.

Documentation

• sunilprakash.com/aip/ -- project hub with guides and tutorials
• Quickstart -- 5 minutes to your first AIP token
• Delegation guide -- chained tokens, scope attenuation, policy profiles
• Competitive analysis -- AIP vs OAuth, DID, UCAN, Macaroons, Biscuit, SPIFFE
• Specification -- full protocol spec

Examples

• Single-agent MCP -- agent authenticates to MCP tool server
• Multi-agent delegation -- orchestrator delegates to specialist, calls tool server

Paper

Sunil Prakash. AIP: Agent Identity Protocol for Verifiable Delegation Across MCP and A2A. arXiv preprint arXiv:2603.24775, 2026. https://arxiv.org/abs/2603.24775

IETF Internet-Draft: draft-prakash-aip-00

@article{prakash2026aip,
  title={AIP: Agent Identity Protocol for Verifiable Delegation Across MCP and A2A},
  author={Prakash, Sunil},
  journal={arXiv preprint arXiv:2603.24775},
  year={2026}
}

Related papers

AIP is part of a multi-agent trust stack:

Layer	Paper	arXiv
Identity	AIP: Verifiable Delegation Across MCP and A2A	2603.24775
Provenance	The Provenance Paradox in Multi-Agent LLM Routing	2603.18043
Protocol	LDP: An Identity-Aware Protocol for Multi-Agent LLM Systems	2603.08852
Reasoning	DCI: Structured Collective Reasoning with Typed Epistemic Acts	2603.11781

Tests

cd python && pytest tests/ -v

License

Apache 2.0