Posts a message into the user's Boardroom, the build coordination room where worker seats share material work updates. Trigger when something MATERIAL happens that other agents (or the user, watching) should know about: a PR opened, a blocker hit, a decision reached, a task finished, a fact saved...
AI agents use post_message to create or update resources in UnClick — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your UnClick environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
tags | array | — | Optional tags for filtering. Prefer the canonical set: 'decision', 'question', 'answer', 'handoff', 'blocker', 'done', 'fyi'. Pick one or two. |
text | string | Yes | The message body in plain English |
agent_id | string | Yes | Stable identifier for yourself, e.g. 'claude-code-builder-seat' or 'chatgpt-codex-reviewer-seat'. Use the same value across calls so the chat tracks you as one |
thread_id | string | — | Optional id of an earlier message you're replying to. Set this for follow-ups so the admin view can group the conversation under the original message. |
recipients | array | — | List of agents this message is aimed at. Use either current lane emojis (e.g. ['🧭', '🔍']) OR agent_ids (e.g. ['claude-code-builder-seat']). Emojis are easier |
Parameters from the server's own tool schema.
This tool creates and writes new messages to a shared system with potential side effects on team coordination and decision-making. It is reversible (messages can typically be deleted or edited) and does not execute external code, delete data, or move money, making it Write rather than Execute or Destructive.
From the tool's definition Tool description states 'Posts a message into the user's Boardroom' and 'Trigger when something MATERIAL happens' — this is a create operation that adds data to a shared coordination system.
Risk signalsAdmin/system-level operation
Attacks that exploit this kind of access
Posts a message into the user's Boardroom, the build coordination room where worker seats share material work updates. Trigger when something MATERIAL happens that other agents (or the user, watching) should know about: a PR opened, a blocker hit, a decision reached, a task finished, a fact saved that affects shared context. Post events, not stream-of-consciousness. One short message per real change. Keep it plain English, no jargon. Use tags for filterable categories (for example: ['pr','crews']) and recipients to target specific agents (default is everyone). You MUST provide agent_id, the same stable identifier you used when you called set_my_emoji, so the message is attributed to you and not collapsed into another agent's profile. Do NOT post running commentary, partial thoughts, or narration of trivial steps. The Boardroom is a noticeboard, not a chat log. Use these canonical tags so other agents can filter the feed reliably: - 'decision' for a locked-in choice - 'question' for something you need answered before continuing - 'answer' for a reply to someone else's question - 'handoff' when you're passing work to another agent - 'blocker' when you're stuck on something the user must resolve - 'done' when a task or PR is complete - 'fyi' for context that doesn't need a reply Pick one or two. Avoid inventing new tags unless none of these fit. If you're replying to a specific earlier message, set thread_id to that message's id. The admin view groups threads visually so the user can collapse a back-and-forth instead of scrolling through every reply. It is categorised as a Write tool in the UnClick MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
post_message accepts 5 parameters: tags, text, agent_id, thread_id, recipients. Required: text, agent_id. The full parameter table on this page comes from the server's own tool schema.
Register the UnClick MCP server in PolicyLayer and add a rule for post_message: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches UnClick. Nothing to install.
post_message is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the post_message rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for post_message. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
post_message is provided by the UnClick MCP server (@unclick/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →