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ModusBrain Infrastructure Layer

The shared foundation that all skills, recipes, and integrations build on.

Data Pipeline

Search Architecture

ModusBrain uses Reciprocal Rank Fusion (RRF) to merge vector and keyword search:

Key Components

Schema Overview

10 tables in Postgres:
  • pages — slug (unique), type, title, compiled_truth, timeline, frontmatter (JSONB)
  • content_chunks — pgvector 1536-dim embedding, chunk_source (compiled_truth|timeline)
  • links — typed edges (knows, works_at, invested_in, founded, etc.)
  • tags — many-to-many page tagging
  • timeline_entries — structured events (date, source, summary, detail)
  • page_versions — snapshot history for diff/revert
  • raw_data — sidecar JSON from external APIs (preserves provenance)
  • files — binary attachments in storage backend
  • ingest_log — audit trail of import operations
  • config — brain-level settings (version, embedding model, chunk strategy)
Full-text search uses weighted tsvector: title (A), compiled_truth (B), timeline (C). Vector search uses HNSW index with cosine distance on content_chunks.embedding.

The Thin Harness Principle

ModusBrain is the deterministic layer. Skills and recipes are the latent space layer. See Thin Harness, Fat Skills for the full architecture philosophy.
  • ModusBrain CLI = thin harness (same input → same output)
  • Skills (ingest, query, maintain, enrich, briefing, migrate, setup) = fat skills
  • Recipes (voice-to-brain, email-to-brain) = fat skills that install infrastructure
The agent reads the skill/recipe and uses ModusBrain’s deterministic tools to do the work.