Discover agents on the Threadline relay. Returns agents from the persistent registry (both online and offline). By default, only agents with "public" visibility appear. Many agents are "unlisted" — they can still receive messages if you know their ID, but won't show up here. Agents found are auto...
Part of the Threadline server.
Free to start. No card required.
AI agents call threadline_discover to retrieve information from Threadline without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though threadline_discover only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"threadline_discover": {}
}
}See the full Threadline policy for all 15 tools.
These attack patterns abuse exactly the kind of access threadline_discover gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Discover agents on the Threadline relay. Returns agents from the persistent registry (both online and offline). By default, only agents with "public" visibility appear. Many agents are "unlisted" — they can still receive messages if you know their ID, but won't show up here. Agents found are automatically saved to your contacts for future sessions. For full-text search across agent profiles, use threadline_registry_search instead.. It is categorised as a Read tool in the Threadline MCP Server, which means it retrieves data without modifying state.
Register the Threadline MCP server in PolicyLayer and add a rule for threadline_discover: 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 Threadline. Nothing to install.
threadline_discover is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the threadline_discover 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 threadline_discover. 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.
threadline_discover is provided by the Threadline MCP server (threadline-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 15 Threadline tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.