Give Agents Typed, Retrievable Knowledge

You need agents that answer questions about relationships between entities. You also need them to look up context by identifier and to find related content by meaning. Today untyped files hold the knowledge, or retrieval depends on an external search engine. Four libraries give you a self-contained knowledge infrastructure that runs locally without external databases: @forwardimpact/libresource, @forwardimpact/libgraph, @forwardimpact/libindex, and @forwardimpact/libvector.

The pipeline flows in three stages: ingest HTML into typed resources, extract RDF triples into a graph, and generate vector embeddings for semantic retrieval. Each stage produces a JSONL-backed index that agents can query directly.

Prerequisites

  • Node.js 22+
  • An embedding endpoint (any OpenAI-compatible /v1/embeddings API) to index vectors
  • HTML files with schema.org microdata markup in a data/knowledge/ directory

Install all four libraries:

npm install @forwardimpact/libresource @forwardimpact/libgraph @forwardimpact/libindex @forwardimpact/libvector

How the pipeline fits together

Each library owns one stage. The output of one stage feeds the next:

data/knowledge/*.html
        |
        v
  libresource          -->  data/resources/*.json     (typed resources)
        |
        +-------+
        |       |
        v       v
  libgraph    libvector
        |       |
        v       v
  data/graphs/  data/vectors/
  index.jsonl   index.jsonl
  ontology.ttl

libindex provides the IndexBase class that both GraphIndex and VectorIndex extend. It persists JSONL, loads on demand, filters by prefix, and holds results within a token budget. The specialized indexes inherit that behavior and do not implement it again.

Where the indexes live: the storage substrate

Every index in this pipeline reads and writes through one backend interface from @forwardimpact/libstorage. The createStorage(prefix) factory returns a storage handle scoped to a named prefix. You construct each index with one:

import { createStorage } from "@forwardimpact/libstorage";

const storage = createStorage("vectors"); // reads/writes data/vectors/

The STORAGE_TYPE environment variable selects the backend for the same call. Consumer code does not change:

STORAGE_TYPE Backend Where data lives
local Local filesystem (default) data/<prefix>/
s3 Amazon S3 or S3-compatible <bucket>/<prefix>/
supabase Supabase Storage <bucket>/<prefix>/

Every index shares this interface. You develop against the local filesystem. You deploy against S3 or Supabase when you set STORAGE_TYPE. The graph, vector, and resource indexes never know which backend they use.

On the local backend, put(key, data) replaces the target atomically. It writes a sibling temp file and then renames it. When the process dies during a write, the target keeps its prior content or holds the new content. The target never holds a truncated prefix.

Install it alongside the index libraries:

npm install @forwardimpact/libstorage

1. Prepare the knowledge directory

Create data/knowledge/. Add HTML files with schema.org microdata. The resource processor extracts typed entities from itemscope / itemtype / itemprop attributes:

<!-- data/knowledge/team.html -->
<!DOCTYPE html>
<html>
<head><base href="https://example.com/team" /></head>
<body>
  <div itemscope itemtype="https://schema.org/Person">
    <span itemprop="name">Alice Chen</span>
    <span itemprop="jobTitle">Senior Engineer</span>
    <link itemprop="worksFor" href="https://example.com/org/acme" />
  </div>
  <div itemscope itemtype="https://schema.org/Organization">
    <meta itemprop="url" content="https://example.com/org/acme" />
    <span itemprop="name">Acme Corp</span>
  </div>
</body>
</html>

The <base href> element sets the IRI for all relative references in the document. Without it, the processor falls back to the --base flag or a default URI.

2. Ingest HTML into typed resources

Run the resource processor to parse every HTML file in data/knowledge/ and store each entity as a typed Message resource:

npx fit-process resources --base=https://example.com/

The processor:

  1. Finds all .html files in data/knowledge/
  2. Sanitizes the DOM (normalizes whitespace, encodes stray characters)
  3. Extracts RDF quads from microdata with the streaming parser
  4. Skolemizes blank nodes into content-hashed URIs for cross-document deduplication
  5. Serializes each entity's triples as Turtle RDF
  6. Stores the result in data/resources/ as a JSON file with a content-hashed identifier

When the same entity appears in multiple HTML files, the processor merges triples with RDF union semantics. It adds new properties. It keeps one copy of each identical triple.

After the processor finishes, verify the resources exist:

ls data/resources/
common.Message.a1b2c3d4.json
common.Message.e5f6g7h8.json

Each file contains the entity's typed identifier, its role (system), and the RDF content as a Turtle string.

3. Build the RDF graph

With resources in place, extract their RDF content into a graph index and generate the ontology:

npx fit-process graphs

The graph processor:

  1. Reads all resource identifiers from data/resources/
  2. Filters to common.Message resources (which contain RDF content)
  3. Parses each resource's Turtle content back into quads
  4. Adds quads to the in-memory N3 triple store, keyed by resource identifier
  5. Writes the graph index to data/graphs/index.jsonl
  6. Builds a SHACL ontology from all observed types and predicates
  7. Writes the ontology to data/graphs/ontology.ttl

The ontology file describes the shape of the data: which types exist, what properties each type has, and how types relate to each other. Agents read this file to learn what questions the graph can answer before they write queries.

Verify that the processor built the graph:

npx fit-rag subjects
https://example.com/team#alice	https://schema.org/Person
https://example.com/org/acme	https://schema.org/Organization

Each line shows a subject URI and its type. Run a triple-pattern query to test a relationship:

npx fit-rag query "?" schema:worksFor "?"
common.Message.a1b2c3d4

The output is the resource identifier that contains the matching triple. The query uses the subject predicate object pattern, where ? is a wildcard. Prefixed names like schema:worksFor expand with the standard prefix map (schema: -> https://schema.org/).

4. Generate vector embeddings

The vector processor takes each resource's text content. It sends the content to an embedding endpoint. It stores the vectors that come back:

npx fit-process vectors

This step needs the embedding gRPC service (@forwardimpact/svcembedding). That service proxies to an OpenAI-compatible Text Embeddings Inference (TEI) backend. Configure it through the service.embedding block in config/config.json or with the SERVICE_EMBEDDING_* environment variables:

{
  "service": {
    "embedding": {
      "backend_port": 8090,
      "model": "BAAI/bge-small-en-v1.5"
    }
  }
}

The processor:

  1. Reads all resource identifiers from data/resources/
  2. Filters out conversations and tool functions
  3. Batches resource content for efficient embedding API calls
  4. Stores each vector alongside its resource identifier in data/vectors/index.jsonl

After the processor finishes, test a semantic search:

npx fit-rag search "senior engineering role"
common.Message.a1b2c3d4	0.8712
common.Message.e5f6g7h8	0.6543

The command ranks results by dot-product score (cosine similarity for normalized vectors). Higher scores show closer semantic matches.

5. Query from code

The CLIs are thin wrappers around the library APIs. For programmatic access, use the libraries directly:

import { createGraphIndex, parseGraphQuery } from "@forwardimpact/libgraph";
import { createResourceIndex } from "@forwardimpact/libresource";

// Query the graph for all Person entities
const graph = createGraphIndex("graphs");
const pattern = parseGraphQuery("? rdf:type schema:Person");
const identifiers = await graph.queryItems(pattern);

// Resolve matched identifiers to full resources
const resources = createResourceIndex("resources");
const items = await resources.get(identifiers.map(String));

for (const item of items) {
  console.log(item.id.type, item.id.name);
  console.log(item.content);   // Turtle RDF string
}

The createGraphIndex("graphs") call reads from data/graphs/. The createResourceIndex("resources") call reads from data/resources/. Both use the data/<prefix>/ convention. Pass a different prefix to point at a different directory.

For vector search from code:

import { VectorIndex } from "@forwardimpact/libvector/index/vector.js";
import { createStorage } from "@forwardimpact/libstorage";

const storage = createStorage("vectors");
const vectorIndex = new VectorIndex(storage);

// Assume you have a query vector from your embedding API
const queryVector = [0.12, -0.34, 0.56, /* ... */];
const results = await vectorIndex.queryItems([queryVector], {
  limit: 5,
  threshold: 0.5,
});

for (const id of results) {
  console.log(String(id), id.score?.toFixed(4));
}

Both queryItems methods accept a filter object with prefix, limit, and max_tokens. These fields scope results by identifier prefix, cap the count, or hold the results within a token budget.

Verify

After you run all three stages, confirm that the full pipeline produced the expected artifacts:

ls data/resources/       # Typed resource JSON files
ls data/graphs/          # index.jsonl + ontology.ttl
ls data/vectors/         # index.jsonl with embeddings

npx fit-rag subjects                           # All subjects and types
npx fit-rag query "?" rdf:type schema:Person   # Graph query
npx fit-rag search "team member"               # Semantic search

Each command should return results drawn from the HTML files you ingested. If a command returns nothing, check that the previous stage completed. Resources must exist before graphs. Resources must exist before vectors.

What's next