Context Blocks

Know what your AI agents don't know.

18 entity types · 6 knowledge layers · 55 relationship types · gap detection first-class, not an afterthought

Every other tool extracts what's there. Context Blocks measures what's not there.

What is Context Blocks?

Context Blocks turns your existing documentation into a typed, layered knowledge base — systems, processes, teams, APIs, business rules, jargon, and decisions. Then it does what standard RAG can't: it stress-tests that knowledge from the point of view of a developer, architect, product owner, and new joiner, and returns a concrete gap report — not a fuzzy "it kind of works."

It can tell you "this KB is 60% complete for a developer, 20% for an architect" rather than just retrieving more text.

The gap is the product. Every unanswered question becomes an explicit curation target with a type, severity, and remediation path — not just "LLM couldn't answer."

Outputs OKF-compatible knowledge bases — directories of Markdown files with YAML frontmatter that any agent, Obsidian vault, or LLM can read directly. No vendor lock-in — because pre-trained agents already understand Markdown + YAML. You shouldn't have to negotiate a proprietary format to see your own knowledge.

What makes this different

	Context Blocks	Typical knowledge tools
Bounded contexts	Knowledge organized into independent blocks — each with its own ontology, entities, and eval scope	One monolithic graph or index
Gap detection	Scores every question as CLEAN / INCOMPLETE / MISSING / TRIBAL	Extract what's there, hope it's enough
Per-block ontology	Each block gets its own meta-model — payments block and compliance block have different entity types	One-size-fits-all schema or no schema
Typed ontology	18 entity types constrained by a meta-model, organized in 6 knowledge layers	Freeform nodes or generic "entity"
Persona evaluation	"60% complete for a developer, 20% for an architect"	No evaluation at all
Research-backed	Built on DDC methodology with empirical evidence that demand-driven curation lifts agent quality	No theoretical foundation

Quick Start — Clone to AI Agent in 10 Minutes

1. Install

From PyPI:

python -m venv .venv
source .venv/bin/activate          # Windows: .venv\Scripts\activate
pip install 'context-blocks[all,mcp]'

From source:

git clone https://github.com/ea-toolkit/context-blocks.git
cd context-blocks
python -m venv .venv
source .venv/bin/activate          # Windows: .venv\Scripts\activate
pip install -e '.[all,mcp]'

This installs the CLI (cb), all document format support (PDF, DOCX, PPTX), and the MCP server.

2. Set API keys

Context Blocks works with multiple LLM providers. Set the key for whichever you use:

# Anthropic (default — uses claude-sonnet-4-6)
export LLM_API_KEY=your-anthropic-key
export LLM_MODEL=claude-haiku-4-5          # optional: cheaper/faster
export LLM_MODEL=claude-opus-4-6           # optional: most capable

# Or use OpenAI
export LLM_PROVIDER=openai
export LLM_MODEL=gpt-4o
export LLM_API_KEY=your-openai-key

# Or use Gemini
export LLM_PROVIDER=gemini
export LLM_MODEL=gemini-2.5-flash
export LLM_API_KEY=your-google-key

Optionally, set an OpenAI key for embeddings (used in retrieval). Without it, Context Blocks falls back to local embeddings automatically:

export OPENAI_API_KEY=your-openai-key       # Optional (embeddings; falls back to local)

3. Prepare your docs

Create a folder anywhere with your company docs. Context Blocks reads Markdown, TXT, HTML, PDF, DOCX, and PPTX. Unsupported files are silently skipped.

my-project/
  seed.md          ← you write this (see below)
  docs/
    architecture.md
    api-spec.pdf
    onboarding.docx
    process-flow.pptx

The seed context (seed.md) is a short markdown file describing your domain — systems, teams, processes, and terminology your AI agent should know about. Think of it as "the onboarding doc you'd give a new engineer on day one." See synthetic-domains/healthcare-claims/seed-context.md for an example.

4. Run the pipeline

Run all commands from the directory that contains my-project/:

# Initialize a context block (creates an output directory)
cb init my-project --seed my-project/seed.md

# Extract entities from your docs
cb extract my-project/docs --seed my-project/seed.md --block my-project

# Merge duplicate entities
cb dedup --block my-project

# Evaluate coverage from multiple perspectives
cb eval --block my-project --seed my-project/seed.md --personas

After each command, here's what success looks like:

Command	What it creates
`cb init`	`.context-blocks/my-project/` directory with config
`cb extract`	Entity markdown files in `.context-blocks/my-project/entities/`, an `analysis-report.md`, and pipeline state for resume
`cb dedup`	Merges duplicate entities, updates files in place
`cb eval`	`evals/` directory with coverage scores per persona and gap classifications (CLEAN / INCOMPLETE / MISSING / TRIBAL)

5. Ask questions

cb ask --block my-project "How does payment authorization work?"
cb ask --block my-project "What happens when a chargeback is filed?"

6. Browse in the viewer

cb serve --block my-project                                    # Terminal 1: API server
cd viewer && CB_OUTPUT_DIR=../.context-blocks/my-project npm run dev   # Terminal 2: Viewer

Opens a web UI at http://localhost:4321 with 8 pages: Digest, Explorer, Map, Workbench, Evals, Glossary, Gaps, and Ask.

Important: The viewer loads entities from CB_OUTPUT_DIR at build time. Without it, it falls back to the demo data. The path is relative to the viewer/ directory — point it at your block's output (e.g., ../.context-blocks/my-project).

7. Connect to Claude Desktop (or any MCP client)

Start the MCP server:

cb mcp --block my-project

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "context-blocks": {
      "command": "/absolute/path/to/your/.venv/bin/cb",
      "args": ["mcp", "--block", "my-project"]
    }
  }
}

Important: Use the full path to cb inside your virtualenv, not just "command": "cb". Claude Desktop doesn't inherit your shell's PATH or virtualenv. Find it with which cb.

Restart Claude Desktop. Your KB is now available as 6 tools: list_blocks, get_overview, search_entities, get_entity, ask_kb, get_gap_report.

Try the Demo (No API Keys Needed)

A synthetic healthcare claims domain ships with 410 pre-extracted entities:

# Browse the pre-built KB in the viewer (uses shipped demo data, no cb serve needed)
cd viewer && npm install && npm run dev
# Open http://localhost:4321

To browse your own block in the viewer, start cb serve --block my-project first, then run the viewer with CB_OUTPUT_DIR pointing at your block's output directory.

cb serve powers the web viewer. cb mcp powers AI agents (Claude Desktop, Copilot). They are separate — you don't need cb serve for Claude Desktop.

Or run the full pipeline yourself on the demo data:

cb extract synthetic-domains/healthcare-claims/docs \
  --seed synthetic-domains/healthcare-claims/seed-context.md \
  --output synthetic-domains/healthcare-claims/output

Features

Context Blocks (Bounded Contexts)

Organize knowledge into scoped blocks — one per domain, team, or product area. Each block is independent with its own entities, relationships, and eval scope:

cb init payments --seed payments-seed.md
cb init identity --seed identity-seed.md
cb init compliance --seed compliance-seed.md

# Work on a specific block
cb extract ./payments-docs --seed payments-seed.md --block payments
cb eval --block payments --seed payments-seed.md --personas

# Set a default so you don't have to pass --block every time
export CB_BLOCK=payments

# MCP server discovers all blocks automatically
cb mcp    # agents call list_blocks() to see what's available

Evaluate

Most tools stop at "search works." Eval is where Context Blocks starts. Generate questions from four sources and measure how well the KB actually answers them:

Source	What it tests
Seed context	Can the KB flesh out what the onboarding doc promises?
Source docs	Did extraction capture what's in the original documents?
Persona templates	Does a developer / architect / PO / new joiner have what they need?
Work items (DDC)	Can the KB help resolve real tickets and incidents?

Retrieve (DAR Pipeline)

Ask questions against your KB with Domain-Aware Retrieval — the same typed retrieval pipeline that backs the DCR paper, productionized and exposed via CLI and MCP:

Typed intent classification — knows if you're asking about a process, system, or relationship
Parallel search — vector + keyword + typed graph traversal
Confidence-weighted RRF fusion with layer priority boosts
Full retrieval traces — see exactly which entities contributed and why

Export to Obsidian

Your KB works natively as an Obsidian vault — entities become interlinked notes with wikilinks, organized by type with a Map of Content:

cb export-obsidian --block my-domain
# Opens as a vault in Obsidian — graph view, backlinks, and search work out of the box

Export for AI Agents

Pack your entire KB into a single markdown file sized for an LLM context window:

cb export-skill --block my-domain --title "My Domain KB"

# With token budget (useful for smaller context windows)
cb export-skill --block my-domain --max-tokens 10000

MCP Server (Agent Integration)

Let AI agents query your KB directly via the Model Context Protocol:

pip install 'context-blocks[mcp]'
cb mcp                                  # stdio (Claude Desktop, local CLI)
cb mcp --transport streamable-http      # HTTP (Copilot, remote agents, web tools)
cb mcp --block my-domain                # serve a single block

6 tools exposed: list_blocks, get_overview, search_entities, get_entity, ask_kb, get_gap_report

Block-aware: agents call list_blocks() first to discover available domains, then pass the block name to any tool. Single-block projects work automatically without specifying.

Configure via env vars or CLI flags:

Setting	Env var	CLI flag	Default
Transport	`CB_MCP_TRANSPORT`	`--transport`	`stdio`
Host	`CB_MCP_HOST`	`--host`	`127.0.0.1`
Port	`CB_MCP_PORT`	`--port`	`8000`

Claude Desktop — see Quick Start step 6 for full setup instructions with virtualenv path.

Remote agents (Copilot, web tools):

cb mcp --transport streamable-http --host 0.0.0.0 --port 8080
# or
export CB_MCP_TRANSPORT=streamable-http
export CB_MCP_HOST=0.0.0.0
export CB_MCP_PORT=8080
cb mcp

Supported LLM Providers

Context Blocks is not locked to any single provider. Set LLM_PROVIDER and LLM_MODEL to switch:

Provider	`LLM_PROVIDER`	Example `LLM_MODEL`	Strategy
Anthropic	`anthropic` (default)	`claude-sonnet-4-6`	Streaming + prompt caching + 3-tier repair
OpenAI	`openai`	`gpt-4o`, `gpt-4o-mini`	Instructor (structured output)
Google Gemini	`gemini`	`gemini-2.5-flash`, `gemini-2.5-pro`	Native JSON schema (constrained decoding)
Any litellm provider	`ollama`, `groq`, `together`, `azure`, ...	Provider-specific	Instructor via litellm

The Anthropic path is the most battle-tested (prompt caching, smart retry, per-entity salvage). OpenAI and Gemini work well. Any provider supported by litellm should work via the Instructor fallback — including local models via Ollama.

Meta-Model

18 entity types organized in 6 knowledge layers:

Layer	Types	Question it answers
Structural	system, software-component, api, data-model, data-product, platform	What exists?
Behavioral	process, business-event, domain-logic	How does it work?
Reference	reference-data	What are the allowed values?
Organizational	team, persona, capability, offering, external-party	Who is involved?
Language	jargon-business, jargon-tech	What do terms mean?
Decision	decision	Why was this chosen?

55 typed relationship types connect entities across layers.

Under the Hood

Capabilities you get without configuring anything:

Capability	What it does
Prompt caching	Anthropic prompt caching + Gemini implicit caching — reduces cost on repeated calls
Crash-safe resume	Pipeline state saved per-document with file hashes — resume after crash without re-processing
3-tier repair ladder	Parse JSON → smart retry (broken JSON only, ~5K tokens) → full retry — maximizes entity salvage
Per-entity validation	Valid entities saved even when some fail — no all-or-nothing batches
Dual embedding providers	OpenAI API if key present, local Fastembed (BAAI/bge-small-en-v1.5) as fallback — works offline
Relationship-aware embeddings	Entity relationships included in embedding text — improves "what connects to X" queries
Post-extraction dedup	LLM-judged duplicate detection with Jaccard similarity pre-filter
Hedged statement detection	Extracts uncertain statements as open questions — surfaces gaps at extraction time
New jargon detection	Flags domain terms not in seed context — auto-discovers terminology
Cost tracking	Per-operation cost estimates including wasted retry tokens
LLM call tracing	Every prompt/response saved to SQLite — full audit trail

CLI Reference

Command	Description
`cb init <name>`	Initialize a new context block
`cb blocks`	List all context blocks
`cb extract`	Extract entities from documents
`cb dedup`	Merge duplicate entities
`cb eval`	Run coverage evaluation
`cb eval --personas`	Include persona-driven completeness checks
`cb eval --work-items <dir>`	Include real work items (DDC mode)
`cb ask "question"`	Ask a question from the terminal
`cb serve`	Start the API server for the viewer
`cb reformat`	Regenerate entity markdown from JSON (no API)
`cb export-obsidian`	Export as Obsidian vault with wikilinks
`cb export-skill`	Export as single markdown for agent context
`cb mcp`	Start MCP server for AI agent integration (stdio)

All commands accept --block <name> or -b. Set CB_BLOCK env var as default.

Cost & Performance

Operation	Typical cost	Sonnet time	Haiku time
Extract 50 docs	~$7	~3-5 hrs	~30-60 min
Extract 6 docs	~$1	~30-40 min	~5-10 min
Eval 30 questions	~$0.60	~10 min	~3 min
Dedup 400 entities	~$0.05	~2 min	~1 min
Single Ask query	~$0.02	~5s	~2s

Sonnet (default) produces higher-quality entities with richer relationships but is slower. For a quick first pass or large document sets, use Haiku:

export LLM_MODEL=claude-haiku-4-5    # 5-10x faster, lower cost

Documents are processed sequentially (each builds on accumulated knowledge from previous docs). The CLI shows progress as [1/6] Extracting: filename.md.

Input Formats

Format	Extension	Install
Markdown	`.md`	Built-in
Plain text	`.txt`	Built-in
HTML	`.html`, `.htm`	Built-in
PDF	`.pdf`	`pip install 'context-blocks[pdf]'`
Word	`.docx`	`pip install 'context-blocks[docx]'`
PowerPoint	`.pptx`	`pip install 'context-blocks[pptx]'`

Or install everything: pip install 'context-blocks[all]'

Confluence exports (HTML) and Notion exports (Markdown) work out of the box.

Configuration

Customize eval personas in context_blocks/config/persona-templates.yaml. Entity types and knowledge layers are defined in viewer/src/config/meta-model.yaml (viewer) and context_blocks/meta_model.py (extraction pipeline).

Research

Built on the Demand-Driven Context (DDC) methodology — empirical evidence that demand-driven curation lifts agent quality where adding more documents alone doesn't.

Paper: arxiv.org/abs/2603.14057
Talks:
- AI.Engineer London 2026 — "Demand-Driven Context for AI Agents"
- CreateWith Brighton 2026 — "Demand-Driven Context for AI Agents" (video coming soon)

License

MIT

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Context Blocks

What is Context Blocks?

What makes this different

Quick Start — Clone to AI Agent in 10 Minutes

1. Install

2. Set API keys

3. Prepare your docs

4. Run the pipeline

5. Ask questions

6. Browse in the viewer

7. Connect to Claude Desktop (or any MCP client)

Try the Demo (No API Keys Needed)

Features

Context Blocks (Bounded Contexts)

Evaluate

Retrieve (DAR Pipeline)

Export to Obsidian

Export for AI Agents

MCP Server (Agent Integration)

Supported LLM Providers

Meta-Model

Under the Hood

CLI Reference

Cost & Performance

Input Formats

Configuration

Research

License

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README.md

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Context Blocks

What is Context Blocks?

What makes this different

Quick Start — Clone to AI Agent in 10 Minutes

1. Install

2. Set API keys

3. Prepare your docs

4. Run the pipeline

5. Ask questions

6. Browse in the viewer

7. Connect to Claude Desktop (or any MCP client)

Try the Demo (No API Keys Needed)

Features

Context Blocks (Bounded Contexts)

Evaluate

Retrieve (DAR Pipeline)

Export to Obsidian

Export for AI Agents

MCP Server (Agent Integration)

Supported LLM Providers

Meta-Model

Under the Hood

CLI Reference

Cost & Performance

Input Formats

Configuration

Research

License