Send cross-project messages and check inbox via Agent Mail — coordinate between agents, send notifications, and read messages. Use when an agent needs to notify another project, check for incoming messages, acknowledge messages, or start a coordination session. Do NOT use for within-project context transfer (use relay:context-gatherer), issue tracking (use relay:issue), or file conflict resolution (use relay:coordinator).
From relaynpx claudepluginhub ivintik/private-claude-marketplace --plugin famdeck-relayThis skill is limited to using the following tools:
Designs and optimizes AI agent action spaces, tool definitions, observation formats, error recovery, and context for higher task completion rates.
Enables AI agents to execute x402 payments with per-task budgets, spending controls, and non-custodial wallets via MCP tools. Use when agents pay for APIs, services, or other agents.
Compares coding agents like Claude Code and Aider on custom YAML-defined codebase tasks using git worktrees, measuring pass rate, cost, time, and consistency.
Cross-project agent messaging via Agent Mail MCP tools.
| Subcommand | MCP Tool | Action |
|---|---|---|
(none) / inbox | mcp__agent-mail__fetch_inbox | List messages as table: ID, From, Subject, Thread, Time |
send <to> <subject> | mcp__agent-mail__send_message | Send or broadcast a message |
ack <message_id> | mcp__agent-mail__acknowledge_message | Acknowledge a message |
thread <thread_id> | mcp__agent-mail__fetch_topic | Fetch full thread |
contacts | mcp__agent-mail__list_contacts | List known agents |
search <query> | mcp__agent-mail__search_messages | Search messages |
start | mcp__agent-mail__macro_start_session | Register identity + fetch inbox in one call |
Load tools via ToolSearch: +agent-mail <tool_name>
Agent Mail organizes everything by project key. Getting this wrong means checking the wrong inbox or sending to the wrong place.
Use fetch_summary with the project directory path to discover the correct project key and any active agents:
fetch_summary(human_key="/path/to/project")
If the project path isn't obvious from context, check the Atlas registry (~/.claude/atlas/registry.yaml) to find registered project paths.
For most tasks, start with macro_start_session — it handles project setup, agent registration, and inbox fetch in one call. Use this instead of manually chaining ensure_project + register_agent + fetch_inbox.
For coordination tasks (announcing work, checking for conflicts), always fetch the inbox before sending. Existing messages may already address what you're about to send — reading first avoids duplicate notifications and lets you reply to threads rather than starting new ones.
Use broadcast=true to reach all registered agents in a project without specifying names. If count: 0 is returned, nobody is currently registered — note this in your response and suggest the recipient registers via macro_start_session.
Don't create placeholder agents in a target project just to have a recipient. If nobody is registered and you can't broadcast, report that clearly and offer to create a relay issue instead.