Compose a validated Flex Message ready for line_send_message. Two input modes: 1. Template mode (recommended for Thai use cases): { template:
AI agents use line_design_flex to create or update resources in Line Oa Mcp Ultimate — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Line Oa Mcp Ultimate environment.
This tool composes/designs a Flex Message structure for later sending. It creates/prepares message content (a Write action) but does not itself send the message or cause irreversible effects. The description is truncated so full capabilities are uncertain, but the primary action is composing/building a message object, not executing a send or deleting data.
From the tool's definition Compose a validated Flex Message ready for line_send_message
Documented attack patterns abuse exactly the kind of access line_design_flex gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Line Oa Mcp Ultimate, and nothing reaches the server without passing your rules. This is the rule we recommend for line_design_flex:
{
"version": "1",
"default": "deny",
"tools": {
"line_design_flex": {
"limits": [
{
"counter": "line_design_flex_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}line_design_flex stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Compose a validated Flex Message ready for line_send_message. Two input modes: 1. Template mode (recommended for Thai use cases): { template:. It is categorised as a Write tool in the Line Oa Mcp Ultimate MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Line Oa Mcp Ultimate MCP server in PolicyLayer and add a rule for line_design_flex: 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 Line Oa Mcp Ultimate. Nothing to install.
line_design_flex 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 line_design_flex 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 line_design_flex. 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.
line_design_flex is provided by the Line Oa Mcp Ultimate MCP server (wasintoh/line-oa-mcp-ultimate). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 34 Line Oa Mcp Ultimate tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
34 Line Oa Mcp Ultimate tools catalogued and risk-classified — across an index of 42,500+ MCP servers.