# add_chat_message_attachment

Attach a file directly to a Huly channel message, direct-message message, or thread reply. Provide filename, contentType, and exactly one source: ${UPLOAD_SOURCE_SEMANTICS}

Agent View of the PolicyLayer registry record for `add_chat_message_attachment`. HTML page: https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/add-chat-message-attachment

## Facts

- Tool: `add_chat_message_attachment`
- Server: Huly (`@firfi/huly-mcp`) — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp.md
- Install: `npx -y @firfi/huly-mcp`
- Homepage: https://github.com/dearlordylord/huly-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "add_chat_message_attachment",
    "arguments": {}
  }
}
```

## Why add_chat_message_attachment is rated Medium

This tool creates or modifies data by attaching files to messages—a reversible write operation. It does not delete data (not Destructive), execute arbitrary code (not Execute), move money (not Financial), or merely read (not Read).

From the tool's own definition: "Tool description states 'Attach a file directly to a Huly channel message, direct-message message, or thread reply' which creates new attachment data associated with existing messages."

## Use case

AI agents use add_chat_message_attachment to create or update resources in Huly, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Huly environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Huly:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_chat_message_attachment": {
      "limits": [
        {
          "counter": "add_chat_message_attachment_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Huly (517)

- `cancel_approval_request` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/cancel-approval-request.md
- `cancel_execution` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/cancel-execution.md
- `delete_activity_reply` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-activity-reply.md
- `delete_association` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-association.md
- `delete_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-attachment.md
- `delete_board_card` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-board-card.md
- `delete_board_label` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-board-label.md
- `delete_card` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-card.md
- `delete_card_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-card-comment.md
- `delete_channel` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-channel.md
- `delete_channel_message` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-channel-message.md
- `delete_chat_message_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-chat-message-attachment.md
- `delete_class_collaborator_metadata` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-class-collaborator-metadata.md
- `delete_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-comment.md
- `delete_component` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-component.md
- `delete_dm_message` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-dm-message.md
- `delete_document` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-document.md
- `delete_drawing` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drawing.md
- `delete_drive` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive.md
- `delete_drive_file_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive-file-comment.md
- `delete_drive_item` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive-item.md
- `delete_event` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-event.md
- `delete_huly_attribute` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-attribute.md
- `delete_huly_enum` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-enum.md
- `delete_huly_permission` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-permission.md
- `delete_huly_sequence` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-sequence.md
- `delete_inventory_category` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-category.md
- `delete_inventory_product` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product.md
- `delete_inventory_product_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product-attachment.md
- `delete_inventory_product_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product-comment.md
- …and 487 more: https://policylayer.com/tools/io-github-dearlordylord-huly-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-dearlordylord-huly-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dearlordylord-huly-mcp