Introduction

Cogitave Core is one canonical model of the whole estate: a property graph that every product, standard, and agent shares. Earlier modules in this path build and query that graph. This module is about the surface an agent actually calls to reach it: the native MCP interface.

"Native" is a specific claim, not a decoration. ADR-0003 records the decision in plain terms: Core's tools and resources over the Model Context Protocol are the canonical query surface, and REST, GraphQL, and llms.txt are generated conveniences over the identical catalog, graph, and search materializations - not the other way around. A human's UI and an agent call the same tool, against the same schema, and get the same answer.

Concretely, Core embeds an MCP server directly in its Rust hot path, targeting spec revision 2025-11-25, reachable over stdio for local agents (the namzu kernel, CI) or Streamable HTTP for edge and remote callers. Every tool's input and output validate against JSON Schema 2020-12 - the same dialect the property graph's own schema uses, so a tool's structured result and the graph model agree by construction rather than by convention.

Everything in this module is grounded in what mcp-interface.md and ADR-0003 actually state today. Read this module the way you would read those documents: as the source of truth, with this module teaching you to use them rather than paraphrasing them from memory.

What you will get from this module

By the end, you will be able to reason about a call to Core over MCP end to end: why the surface is native rather than adapted, what protocol guarantees you can rely on - transports, schema dialect, the error model - which tools and resources exist and what each one returns, and where the governance tools stop at "propose" instead of "mutate."

Where this fits

This is module 3 of Build on Cogitave Core. It assumes you can already picture Core as a property graph and does not re-teach that model; if a term here is unfamiliar, mcp-interface.md links onward to the substrate and query docs it builds on.