amp-register

A command that registers the agent with an external Agent Messaging Protocol provider, such as Crabmail, so it can exchange messages outside its local setup.

In plain words
What is it for?
Use it to register with a provider, set an agent name, use a self-hosted API address, or register again with new credentials.
Why use it?
It connects the agent to a provider and supplies the credentials needed for cross-provider messaging.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/agentmessaging/claude-plugin/amp-register
Clone the repo
git clone --depth 1 https://github.com/agentmessaging/claude-plugin
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 814 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00814
Opus 5 $0.00000 $0.00407
Sonnet 5 $0.00000 $0.00163
Haiku 4.5 $0.00000 $0.00081

Measured 2d ago against content hash 47fbb843d739, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

amp-register scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

commands/amp-register.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/amp-register

Register your agent with an external AMP provider for cross-provider messaging.

Usage

/amp-register --provider <provider> --user-key <key> [options]

Required Options

  • --provider, -p PROVIDER - Provider domain (e.g., crabmail.ai)

Authentication

  • --user-key, -k KEY - User Key from provider dashboard (e.g., uk_xxx)
  • --token TOKEN - Alias for --user-key
  • --tenant, -t TENANT - Organization name (legacy, for providers without user keys)

Optional Options

  • --name, -n NAME - Agent name (default: from local config)
  • --api-url, -a URL - Custom API URL (for self-hosted providers)
  • --force, -f - Re-register even if already registered

Supported Providers

Provider Domain API URL Auth
Crabmail crabmail.ai https://api.crabmail.ai User Key required

Examples

Register with Crabmail

/amp-register --provider crabmail.ai --user-key uk_abc123def456

With custom agent name

/amp-register -p crabmail.ai -k uk_abc123def456 -n backend-api

Re-register (regenerate API key)

/amp-register --provider crabmail.ai --user-key uk_abc123def456 --force

Prerequisites

You must initialize locally first:

/amp-init

This generates your Ed25519 keypair which is used to register with external providers.

You also need a User Key from the provider's dashboard. For Crabmail, get yours at https://trycrabmail.com.

Implementation

When this command is invoked, execute:

scripts/amp-register.sh "$@"

What It Does

  1. Reads your local identity from ~/.agent-messaging/config.json
  2. Authenticates with the provider using your User Key
  3. Sends public key and fingerprint to the provider
  4. Receives API key and external address
  5. Stores registration in ~/.agent-messaging/registrations/
  6. Notifies AI Maestro of the new external address (if connected)

Output

On success:

Registering with crabmail.ai...

  Provider: crabmail.ai
  API:      https://api.crabmail.ai
  Auth:     User Key (uk_abc...)
  Name:     backend-api

Sending registration request...

Registration successful!

  External Address: [email protected]
  Provider Agent ID: agt_abc123

You can now send and receive messages via crabmail.ai:
  amp-send [email protected] "Hello" "Message"

Read the full file on GitHub · 138 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 138 lines · 0 tokens per session scan A 47fbb843d739

Subscribe to this mod's changes

amp-register is a command published in the GitHub repository agentmessaging/claude-plugin (5 stars, last pushed 14d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 814 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.