pg_transaction_begin
Begin a new transaction. Returns a transaction ID for subsequent operations.
This record as markdown: /tools/io-github-neverinfamous-postgres-mcp/pg-transaction-begin.md
What pg_transaction_begin does on PostgreSQL MCP Server
AI agents invoke pg_transaction_begin 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_transaction_begin is rated High
Beginning a transaction initiates a database session context that enables subsequent operations (potentially including destructive or financial ones). It is an execution trigger rather than a pure read or write, and its risk depends on what follows — but the act itself is an Execute-category operation that opens a stateful transaction handle.
From the tool's definition 'Begin a new transaction. Returns a transaction ID for subsequent operations.'
Attacks that exploit this kind of access
The rule that runs pg_transaction_begin 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_transaction_begin, this is the rule to start with:
pg_transaction_begin 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_transaction_begin call is checked against it from then on.
Questions about pg_transaction_begin
Begin a new transaction. Returns a transaction ID for subsequent operations. 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_transaction_begin: 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_transaction_begin 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_transaction_begin 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_transaction_begin. 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_transaction_begin 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.
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