acpctl 0.1.3

ACP — Agent Communication Protocol CLI

Command-line interface for ACP identity management, discovery, and message delivery. ACP (Agent Communication Protocol) is a secure, identity-driven protocol for autonomous systems to communicate, collaborate, and coordinate across environments. Unlike traditional API integrations or message brokers, ACP is designed for AI agents operating in dynamic, distributed ecosystems. This project is not related to other packages using the acronym "ACP"

HTTP is for services. ACP is for agents.

What is ACP?

ACP provides:

• Identity-first communication between agents
• Signed and optionally encrypted message envelopes
• Transport independence (HTTP, AMQP, MQTT)
• Relay-based routing across network boundaries
• Capability-driven interaction patterns

This enables agents to discover each other, exchange messages, and collaborate without tight coupling.

What ACP Is Not

• Not a message broker.
• Not a JSON schema format.
• Not a framework-specific tool protocol.

Why ACP?

Modern systems are evolving from services into autonomous agents. Current approaches (REST APIs, webhooks, point-to-point messaging) lead to:

• brittle integrations
• hidden coupling
• limited interoperability
• lack of governance

ACP introduces a protocol layer for agent communication, similar to how HTTP enabled the web.

When to Use ACP

Use ACP when:

• autonomous agents need to communicate across teams, runtimes, or network boundaries
• identity and message verification are required at the protocol level
• you want one protocol across direct and relay delivery paths

ACP may be unnecessary when:

• one application calls one service with stable, tightly controlled APIs
• plain HTTP/REST already solves the integration with low coordination overhead

ACP vs Typical Approaches

Approach	Good fit	Gaps for autonomous agent communication
REST APIs	stable service-to-service calls	endpoint coupling and custom identity/discovery conventions
Webhooks	event callbacks	delivery and trust rules vary by implementation
Message brokers	high-throughput internal messaging	broker-specific semantics, no shared agent protocol layer
Agent tool protocols	tool invocation inside one framework	often framework-scoped, not cross-runtime protocol contracts
ACP	cross-agent protocol with identity + secure envelopes	adds protocol concepts not needed for trivial single-service cases

SDK Installation Parity

Status labels used in this repo:

• Published
• Available from repo
• Coming

| SDK | Status | | Python (acp-runtime) | Published| | TypeScript (acp-runtime) | Published| | Rust (acp) | Available from repo| | Go (github.com/acp/sdk-go) | Available from repo| | Java (io.acp:acp-sdk) | Available from repo | | Mojo wrapper (acp-sdk-mojo) | Available from repo |

No SDK in this repository snapshot is currently labeled Coming.

Repo Structure

• getting-started/: verified local ping flow
• examples/: runnable demos (hello_world_agent.py, one-to-one, one-to-many, capabilities)
• sdks/: language SDK implementations
• cli/: ACP CLI (acp)
• relay-dev/: developer relay for local/test routing

Open Source Scope

This repository is for learning, local development, and interoperability testing.

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Install

Published packages:

pip install acp-runtime acpctl

From this repository:

pip install -e sdks/python -e cli

Check installation:

acp --help

First run

Use the repository quickstart ping flow:

./getting-started/quickstart_ping.sh

Details: getting-started/README.md.

Common commands

acp identity create --agent-id agent:demo.bot@localhost:9010 --direct-endpoint http://localhost:9010/acp/inbox
acp message send --from agent:demo.bot@localhost:9010 --to agent:peer.bot@localhost:9011 --payload-json '{"type":"ping"}' --delivery-mode direct --allow-insecure-http
acp message capabilities --from agent:demo.bot@localhost:9010 --to agent:peer.bot@localhost:9011 --allow-insecure-http