Check the state of all available exchanges, time to open, and time to close. Returns all available stock exchanges by default.
AI agents call GetMarketState to retrieve information from Twelve Data MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
GetMarketState performs a read-only query of exchange status and timing data. It retrieves information about market hours and states without modifying, executing operations, or affecting financial positions. No authentication or authorization concerns apply to reading public market state data. The blast radius of misuse is negligible—an agent cannot cause harm by repeatedly calling this tool.
From the tool's definition Tool returns exchange state information: 'Check the state of all available exchanges, time to open, and time to close.' This is a query operation that retrieves market metadata with no side effects.
Documented attack patterns abuse exactly the kind of access GetMarketState gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Twelve Data MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for GetMarketState:
{
"version": "1",
"default": "deny",
"tools": {
"GetMarketState": {}
}
}GetMarketState is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check the state of all available exchanges, time to open, and time to close. Returns all available stock exchanges by default. It is categorised as a Read tool in the Twelve Data MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Twelve Data MCP Server MCP server in PolicyLayer and add a rule for GetMarketState: 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 Twelve Data MCP Server. Nothing to install.
GetMarketState 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 GetMarketState 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 GetMarketState. 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.
GetMarketState is provided by the Twelve Data MCP Server MCP server (twelvedata/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 186 Twelve Data MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
186 Twelve Data MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.