pg_kcache_create_extension
Enable the pg_stat_kcache extension for OS-level performance metrics. Requires pg_stat_statements to be installed first. Both extensions must be in shared_preload_libraries.
This record as markdown: /tools/io-github-neverinfamous-postgres-mcp/pg-kcache-create-extension.md
What pg_kcache_create_extension does on PostgreSQL MCP Server
AI agents invoke pg_kcache_create_extension to trigger actions in PostgreSQL MCP Server. 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.
Why pg_kcache_create_extension is rated High
Installing a PostgreSQL extension executes DDL statements that modify the database system catalog and enable new functionality. While technically a 'create' operation, it triggers execution of database-level system changes that affect server behavior. It is not purely reversible Write (it changes server-level shared libraries configuration and system state), making Execute the most appropriate category.
From the tool's definition 'Enable the pg_stat_kcache extension' — creates/installs a database extension, which executes DDL (CREATE EXTENSION) and modifies the database system configuration
Attacks that exploit this kind of access
The rule that runs pg_kcache_create_extension safely
PolicyLayer is an MCP gateway: it sits between your AI agents and PostgreSQL MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For pg_kcache_create_extension, this is the rule to start with:
pg_kcache_create_extension stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect PostgreSQL MCP Server, apply this rule, and every pg_kcache_create_extension call is checked against it from then on.
Questions about pg_kcache_create_extension
Enable the pg_stat_kcache extension for OS-level performance metrics. Requires pg_stat_statements to be installed first. Both extensions must be in shared_preload_libraries. It is categorised as a Execute tool in the PostgreSQL MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the PostgreSQL MCP Server MCP server in PolicyLayer and add a rule for pg_kcache_create_extension: 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 PostgreSQL MCP Server. Nothing to install.
pg_kcache_create_extension 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 pg_kcache_create_extension 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 pg_kcache_create_extension. 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.
pg_kcache_create_extension is provided by the PostgreSQL MCP Server MCP server (@neverinfamous/postgres-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on PostgreSQL MCP Server, and thousands of servers like it.
Across the catalogue