prism-rag 0.2.8

Epistemic Graph RAG with Spreading Activation — retrieval that understands how knowledge relates, not just what it says

PRISM — Epistemic Graph RAG with Spreading Activation

Propagation & Retrieval via Informed Semantic Mapping

_{This project was designed and directed by a human author. Code, documentation, and the research paper were substantially drafted with the assistance of Claude Sonnet 4.6 (Anthropic). Architecture decisions, domain framing, and editorial judgement remain the author's own. Disclosed using the AI Attribution Toolkit.}

PRISM layers a typed epistemic knowledge graph over your existing vector store, then uses spreading activation to surface knowledge structured by how it relates — not just how similar it is.

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The Problem with Standard RAG

Standard RAG returns a flat ranked list. Every chunk gets a similarity score and nothing else:

query → embed → similarity → [chunk, chunk, chunk, ...]   ← no structure

Chunk B may refute Chunk A. Chunk C may specialise a principle in Chunk D. An older document may have been superseded. Standard RAG can't express any of this.

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What PRISM Does

PRISM builds a graph where edges carry epistemic type:

Doc A  ──[supports]──▶  Doc B
Doc C  ──[refutes]───▶  Doc D
Doc E  ──[supersedes]▶  Doc F

Retrieval uses spreading activation: a query fires seed nodes via vector search, activation propagates through typed edges, and nodes reached by multiple independent paths (convergence) rank highest.

The result is a structured epistemic answer with five buckets:

Bucket	Contents
PRIMARY	Core relevant chunks, highest convergence
SUPPORTING	Chunks that reinforce or extend the primary answer
CONTRASTING	Chunks that challenge or take a different position
QUALIFYING	Chunks that add conditions, exceptions, or nuances
SUPERSEDED	Historically relevant context now replaced by newer work

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Installation

# Core — bring your own vector store adapter
pip install prism-rag

# With a built-in adapter:
pip install prism-rag[lancedb]    # LanceDB
pip install prism-rag[chroma]     # ChromaDB
pip install prism-rag[qdrant]     # Qdrant
pip install prism-rag[weaviate]   # Weaviate (v4 client)
pip install prism-rag[pgvector]   # PostgreSQL + pgvector

# With the interactive explorer:
pip install prism-rag[lancedb,explorer]

# With Neo4j Bolt export:
pip install prism-rag[neo4j]

Requires Python 3.11+ and an embedding provider (Ollama or any OpenAI-compatible API).

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CLI Quickstart

This is the typical end-to-end workflow from an existing vector store to structured retrieval.

Step 1 — Build the graph

Point PRISM at your existing LanceDB store. The graph is built once and saved to a .json.gz file.

prism-build \
  --lancedb-path /path/to/lancedb \
  --graph-path   prism_graph.json.gz \
  --llm-api-key  $OPENAI_API_KEY

With Ollama embeddings and a local filter model:

prism-build \
  --lancedb-path  /path/to/lancedb \
  --graph-path    prism_graph.json.gz \
  --ollama-url    http://localhost:11434 \
  --embed-model   nomic-embed-text \
  --filter-model  llama3.1:8b \
  --llm-base-url  https://api.openai.com \
  --llm-model     gpt-4o-mini \
  --llm-api-key   $OPENAI_API_KEY

If interrupted, the build resumes automatically from its checkpoint — just re-run the same command.

Step 2 — Verify the graph

prism-stats prism_graph.json.gz

Also show LanceDB stats alongside:

prism-stats prism_graph.json.gz --lancedb-path /path/to/lancedb

Output JSON for scripting:

prism-stats prism_graph.json.gz --json

Step 3 — Explore interactively

prism-explore \
  --lancedb-path /path/to/lancedb \
  --graph-path   prism_graph.json.gz \
  --embed-model  nomic-embed-text

Open http://localhost:7860 to get a force-directed graph with semantic search. Type a question and watch activation spread — nodes glow by bucket (primary / supporting / contrasting / qualifying / superseded).

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CLI Reference

prism-build — Build the epistemic graph

prism-build --lancedb-path PATH --graph-path PATH [options]

Graph shape:

Flag	Default	Description
--k-neighbors	8	Semantic neighbours per chunk used as candidate pairs
--cross-source-only	off	Only extract edges between different source documents
--min-confidence	0.65	Drop edges below this confidence score
--max-pairs	unlimited	Cap candidate pairs (useful for large corpora)
--force	off	Rebuild even if the graph file already exists
--no-resume	off	Ignore checkpoint, start from scratch

Embeddings:

Flag	Default	Description
--table-name	knowledge	LanceDB table name
--ollama-url	http://localhost:11434	Ollama base URL
--embed-model	nomic-embed-text	Embedding model (must match ingest-time model)

Stage 1 — local filter (fast, free):

Flag	Default	Description
--filter-model	llama3.1:8b	Ollama model for binary pre-filter
--filter-batch-size	10	Pairs per Ollama call
--filter-concurrency	5	Concurrent Ollama requests
--no-filter	off	Skip Stage 1 (if Ollama is unavailable)

Stage 2 — LLM extraction:

Flag	Default	Description
--llm-base-url	https://api.deepseek.com	OpenAI-compatible API base URL
--llm-model	deepseek-chat	Model for epistemic extraction
--llm-api-key	""	API key (or set OPENAI_API_KEY / DEEPSEEK_API_KEY)
--batch-size	20	Pairs per LLM call
--max-concurrent	20	Concurrent Stage 2 API requests
--failure-log	none	Path to write JSON log of failed extraction batches

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prism-stats — Graph and store statistics

prism-stats GRAPH_PATH [--lancedb-path PATH] [--table-name NAME] [--json]

Prints node count, edge count, edge-type breakdown, and density. Add --lancedb-path to also report vector store chunk count and source breakdown.

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prism-inspect — Inspect a single node

prism-inspect GRAPH_PATH --node NODE_ID [--max-edges N] [--json]

Shows the node's metadata and all its incoming and outgoing edges with types and confidence scores. Useful for debugging why a chunk is or isn't appearing in retrieval.

prism-inspect prism_graph.json.gz --node "chunk_abc123" --max-edges 30

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prism-explore — Interactive web explorer

prism-explore --lancedb-path PATH --graph-path PATH [options]

Flag	Default	Description
--table-name	knowledge	LanceDB table name
--ollama-url	http://localhost:11434	Ollama base URL
--embed-model	nomic-embed-text	Embedding model
--embed-api-url	none	OpenAI-compatible embedding API URL
--embed-api-key	none	Embedding API key
--host	127.0.0.1	Bind host
--port	7860	Bind port

With an OpenAI-compatible embedding API instead of Ollama:

prism-explore \
  --lancedb-path  /path/to/lancedb \
  --graph-path    prism_graph.json.gz \
  --embed-api-url https://api.openai.com/v1/embeddings \
  --embed-api-key $OPENAI_API_KEY \
  --embed-model   text-embedding-3-small

The explorer lets you:

• Browse the force-directed epistemic graph (15k+ nodes)
• Toggle edge types on/off, filter by source, set a confidence floor
• Type a question and watch spreading activation colour nodes by result bucket
• Click any node to see its connections in a side panel
• Export the current layout as a standalone interactive HTML file

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prism-viz — Export for Gephi or D3

prism-viz GRAPH_PATH [--format gexf|d3] [--output PATH] [options]

Flag	Default	Description
--format	d3	d3 (JSON for D3.js) or gexf (Gephi)
--output, -o	auto	Output file; use - to write D3 JSON to stdout
--edge-types	all	Comma-separated list: supports,refutes,supersedes,…
--min-confidence	0.0	Drop edges below this threshold
--source-filter	none	Only include nodes whose source contains this string
--max-nodes	unlimited	Keep the top-N highest-degree nodes only

# Export high-confidence supports/refutes edges for one document set
prism-viz prism_graph.json.gz \
  --format gexf \
  --edge-types supports,refutes \
  --min-confidence 0.8 \
  --output review_graph.gexf

# Pipe D3 JSON into another tool
prism-viz prism_graph.json.gz --output - | jq '.nodes | length'

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prism-export — Export to Neo4j

prism-export GRAPH_PATH [--format cypher|neo4j] [options]

Write a Cypher script (no Neo4j required):

prism-export prism_graph.json.gz --format cypher --output graph.cypher

# Load it:
cypher-shell -u neo4j -p secret < graph.cypher

Push directly via Bolt:

pip install prism-rag[neo4j]

prism-export prism_graph.json.gz \
  --format neo4j \
  --uri      bolt://localhost:7687 \
  --user     neo4j \
  --password secret \
  --clear           # wipe existing :Chunk nodes first

Flag	Default	Description
--batch-size	500	Nodes/edges per transaction
--database	neo4j	Target Neo4j database name
--clear	off	Delete all :Chunk nodes before import

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Python API Quick Start

Build the graph

from prism import PRISM

p = PRISM(
    lancedb_path = "/path/to/lancedb",
    graph_path   = "prism_graph.json.gz",
    ollama_url   = "http://localhost:11434",
    embed_model  = "nomic-embed-text",
    llm_base_url = "https://api.openai.com",
    llm_model    = "gpt-4o-mini",
    llm_api_key  = "sk-...",
)

p.build(k_neighbors=8, cross_source_only=False)

Retrieve

p.load_graph()
result = p.retrieve("your question here", top_k=5)
print(result.format_for_llm())

Output:

PRISM retrieval for: "your question here"
────────────────────────────────────────────────────────────

## PRIMARY
[1] source-a  p.14  § 2.1  (score: 0.923)
    The core relevant passage...

## SUPPORTING EVIDENCE
[1] source-c  p.201  § 8.2  (score: 0.841  [via: specializes])
    A passage that extends the primary answer...

## QUALIFICATIONS & NUANCES
[1] source-d  p.38  § 3.1  (score: 0.712  [via: qualifies])
    A passage adding conditions or exceptions...

─ 1 primary · 1 supporting · 0 contrasting · 1 qualifying · 0 superseded ─

Access results programmatically

for chunk in result.primary:
    print(chunk.source, chunk.page, chunk.final_score, chunk.text)

for chunk in result.contrasting:
    print("Contrasting view:", chunk.text[:200])

# Feed structured context directly into your LLM
context = result.format_for_llm()

Export the graph

import networkx as nx

# NetworkX — use any graph algorithm
G = graph.to_networkx()          # returns nx.MultiDiGraph copy
pr = nx.pagerank(G, weight="weight")
communities = nx.community.greedy_modularity_communities(G.to_undirected())

# Cypher script
graph.to_cypher("graph.cypher")

# Neo4j Bolt
graph.to_neo4j("bolt://localhost:7687", user="neo4j", password="secret")

---

Epistemic Edge Types

supports        — A provides evidence reinforcing B
refutes         — A directly contradicts B
supersedes      — A replaces or updates B
derives_from    — A is logically derived from B
specializes     — A is a specific instance of B
contrasts_with  — A and B take different, non-exclusive positions
implements      — A is a concrete method putting B into practice
generalizes     — A is a broader abstraction of which B is a case
exemplifies     — A is a concrete example illustrating B
qualifies       — A adds conditions, exceptions, or nuances to B

Each edge carries a propagation weight (0.40–0.90) and a valence that determines which result bucket its target lands in.

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Build Performance

The graph is built once offline. PRISM uses a two-stage pipeline that makes large-corpus builds practical:

Stage 1 — Ollama pre-filter (fast, free) An Ollama model screens candidate pairs with a binary yes/no question. ~50% of pairs are discarded before any API call. Runs via Ollama, costs nothing.

Stage 2 — Async LLM classification Surviving pairs are classified with full type + confidence using 20 concurrent API requests, in batches of 20 pairs each.

Build time — 30k-chunk corpus, ~50k candidate pairs:

Pipeline	Wall Time
v1 — sync, batch=5	~40 hours
v2 — async only, batch=20	~30 minutes
v2 — async + stage-1 filter	~15–20 minutes

Checkpoint / resume — if interrupted, the build saves progress automatically and resumes from where it left off.

cross_source_only=False produces significantly richer graphs. On a 30k-chunk governance corpus: True = 3,571 edges (graph rarely fires); False = 9,989 edges (supporting/qualifying buckets activate on most queries). Use False unless your sources are genuinely independent.

Choosing a Stage 1 filter model — use a model under ~5 GB. Small, fast models (llama3.1:8b, llama3.2:3b, gemma3:4b) complete each binary call in under a second. Models above ~6 GB can take 2–4 seconds per call and negate the benefit of filtering entirely. If no fast model is available, use --no-filter and rely on Stage 2 alone (~30 min).

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No Re-embedding Required

PRISM works on top of your existing vector store. If you have an existing corpus with embeddings, you don't need to re-index anything.

• Existing vectors → used as-is for seed activation
• Epistemic graph → built from text via LLM, stored as a separate .json.gz file
• Fallback → if no graph exists, PRISM automatically falls back to pure vector search

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Vector Store Adapters

PRISM ships adapters for LanceDB, ChromaDB, Qdrant, Weaviate, and pgvector. All share the same interface:

from prism.adapters.chroma   import ChromaAdapter
from prism.adapters.qdrant   import QdrantAdapter
from prism.adapters.weaviate import WeaviateAdapter
from prism.adapters.pgvector import PgvectorAdapter

adapter = QdrantAdapter(collection_name="knowledge", url="http://localhost:6333")
p = PRISM(graph_path="prism_graph.json.gz", adapter=adapter, ...)

To connect a different store, implement the VectorAdapter Protocol — copy prism/adapters/template.py for a fully-commented skeleton.

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Embedding Providers

Ollama (local):

PRISM(ollama_url="http://localhost:11434", embed_model="nomic-embed-text", ...)

OpenAI-compatible API (OpenAI, Azure, Together, Jina, Mistral, etc.):

PRISM(embed_api_url="https://api.openai.com/v1/embeddings", embed_api_key="sk-...", ...)

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Links

• Full documentation & architecture: github.com/MadMando/prism
• Issues: github.com/MadMando/prism/issues

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Changelog

0.2.7 — NetworkX and Neo4j export

G = graph.to_networkx()          # nx.MultiDiGraph copy — use any nx algorithm
graph.to_cypher("graph.cypher")  # write Cypher script
graph.to_neo4j("bolt://localhost:7687", user="neo4j", password="secret")

CLI:

prism-export graph.json.gz --format cypher --output graph.cypher
prism-export graph.json.gz --format neo4j --uri bolt://localhost:7687 \
  --user neo4j --password secret

Install: pip install prism-rag[neo4j] for direct Bolt push.

0.2.6 — Local interactive graph explorer

pip install prism-rag[lancedb,explorer]

prism-explore \
  --lancedb-path /path/to/lancedb \
  --graph-path   prism_graph.json.gz \
  --embed-model  nomic-embed-text

Open http://localhost:7860 — force-directed graph, edge-type toggles, confidence slider, semantic query mode, Export HTML.

0.2.5 — Adapter bug fixes

• LanceDB: get_chunks no longer silently drops node IDs past the first 100.
• ChromaDB: dropped the invalid $contains where filter; source_filter now applies client-side.
• Weaviate: vectors cached in initial scan — no more N+1 round-trips in candidate_pairs_for.
• pgvector: separate cursors for fetch and neighbour queries (avoids psycopg2 buffer-invalidation).
• Tests added for all five adapters and prism-viz. CI now runs a matrix over all extras with a 50% coverage floor.

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License

MIT