Execute a GraphQL query against the Tacit building digital twin API. Compose any query using the Brick-compliant schema. Supports nested fields, filtering by Brick class, supply chain traversal (upstream/downstream), and recursive location hierarchy. Use tacit_list_sites first to get a valid site...
AI agents invoke tacit_graphql to trigger actions in Tacit MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool allows execution of arbitrary GraphQL queries against a building management API. While it is read-focused in typical usage (querying sensor data, building topology), the ability to compose 'any query' and execute it against a digital twin system represents code execution capability that could trigger external operations on building infrastructure if the schema permits mutations.
From the tool's definition Execute a GraphQL query against the Tacit building digital twin API. Supports nested fields, filtering by Brick class, supply chain traversal (upstream/downstream), and recursive location hierarchy. Compose any query using the Brick-compliant schema.
Attacks that exploit this kind of access
Execute a GraphQL query against the Tacit building digital twin API. Compose any query using the Brick-compliant schema. Supports nested fields, filtering by Brick class, supply chain traversal (upstream/downstream), and recursive location hierarchy. Use tacit_list_sites first to get a valid site ID, then construct queries freely. Args: - site_id (string, required): The site ID (injected as siteId into your query variables) - query (string, required): GraphQL query string - variables (string, optional): JSON-encoded variables object (siteId is auto-injected) ${SCHEMA_REFERENCE}. It is categorised as a Execute tool in the Tacit MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Tacit MCP server in PolicyLayer and add a rule for tacit_graphql: 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 Tacit MCP. Nothing to install.
tacit_graphql is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the tacit_graphql 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 tacit_graphql. 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.
tacit_graphql is provided by the Tacit MCP server (ucl-sbde/tacit-mcp). 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.
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