MCP and connected context

Shared by Pavel · Updated 2026-11-03

Substrate connects information sources through pre-built connectors and makes its context available to agents through MCP; the connector experience works, but parts of setup and the underlying search pipeline remain unfinished. (more: Connector implementation and rollout)

Updated 30 Oct 2026 with new facts.

Connecting agents and external sources

• Substrate has first-class pre-built connectors for Notion, Gmail, and WhatsApp, plus a way to connect any MCP-enabled service.
• Users can connect apps through MCP, including by pasting a link to an MCP-enabled page; connections typically use OAuth.
• MCP is the interoperability layer: it standardizes how agents connect to external tools and data, and lets agents call Substrate rather than relying on context being injected into every prompt.
• A Substrate MCP server is implemented, and at least one MCP request succeeded; one observed request took 5.8 seconds.

What is implemented

• The product has named pre-built connectors for Notion, Gmail, and WhatsApp, alongside the general MCP connection path.
• MCP connectors are described as part of the core experience, and the product supports connecting an MCP-enabled app.
• Gmail is an ingestion source, but access still depends on completing Google OAuth verification and a CASA assessment.

What remains unfinished

• Google OAuth verification and CASA assessment for Gmail access were open tasks; unverified apps were capped at 100 users.
• Closing the remaining shadow-ledger and search integration was also an open task. The shadow ledger remained private and non-searchable during extraction, with quality-v2 content isolated until cutover.
• MCP resources and templates were empty, so the described integration experience was centered on tool connections rather than a populated resource/template layer.