External integrations (MCP)
MCP overview
MCP (Model Context Protocol) is the open standard for connecting LLMs to external tools and data. Pitchbar acts as an MCP client: buyers connect their MCP servers (CRMs, calendars, inventory, internal APIs) and the agent calls tools mid-conversation when the visitor's question needs live data the crawl can't provide.
What it unlocks
- The bot looks up an order status in Shopify before answering "where is my package?"
- The bot books a demo on Cal.com without leaving the chat.
- The bot fetches the visitor's open tickets from HubSpot to give context-aware replies.
- The bot queries the buyer's own internal API via their custom MCP server.
Architecture in one paragraph
MCP servers belong to the workspace: every agent's MCP page lists
all of them, with how many of each server's tools that agent may
use. The admin explicitly enables each tool per agent — destructive
tools (writes
to the external system) require a confirmation dialog. At
runtime, the agent's tool-call loop merges built-in tools
(escalate_to_human, etc.) with MCP-discovered tools. When the
LLM decides to call an MCP tool, the request goes through a
rate-limited, circuit-breakered executor that wraps the tool
output in <tool-result trusted="false"> tags
so the system prompt can treat it as data, not instructions.
Hard rules
- Whitelist by default. Discovered tools land in the catalogue as disabled. An admin explicitly turns each one on per agent.
- Schema drift = re-approval. When a tool's input shape changes between catalogue refreshes, every existing grant is auto-disabled so the admin re-acks the new parameters.
- SSRF guard. Server URLs that resolve to private / loopback / cloud-metadata addresses are rejected at validation time AND at every call.
- Token budget. Tool outputs are truncated to 1200 tokens by default (per-tool override allowed) so a chatty MCP server can't blow the model's context window.
- Audit trail. Every call is logged with status, latency, args preview, output preview, and a ULID request id for cross-system correlation.