Coding Agents Need Typed Context Surfaces, Not One Flat Context Window

Most coding agents treat context as a combination of source files, chat history, configuration files, and retrieved text. That works for simple code completion, but becomes unreliable when a task requires exact values, structured relationships, reusable procedures, or durable project-specific facts.

The problem is that different information types have different access patterns:

- Documents require semantic and keyword retrieval.

- Structured data requires filtering, joins, aggregation, and SQL.

- Relationships require graph traversal rather than text similarity.

- Procedures need reusable, versioned instructions.

- Durable facts need scope, persistence, and controlled updates.

A practical architecture is to expose these as typed context surfaces instead of flattening them into a single vector index:

- KB for documents and notes, with hybrid retrieval.

- DB for structured records and SQL queries.

- Graph for entities, relationships, and bounded traversal.

- Skills for reusable operational procedures.

- Memory for scoped facts, preferences, and durable state.

The agent can route each request to the relevant surface, combine results when necessary, and preserve provenance for every piece of evidence. Read operations and write operations should also remain separate: retrieval returns normalized evidence, while updates return explicit receipts containing the affected source, profile, revision, and surface-level results.

This architecture is currently implemented in the open-source Codex MCP plugin OpenDCAI/DataMind .