Configure Graph RAG
Graph RAG is a retrieval tool you add to a Touchpoint. It searches your Knowledge for relevant resources, then follows the relationships between them to find more. This guide takes you from a new Knowledge to a working, tuned Graph RAG tool.
A basic (naive) RAG search finds resources that match the meaning of a query. Graph RAG does that first, then traverses the knowledge graph to pull in related resources the meaning-only search would miss.
Prerequisites
Before you start, make sure you have:
- Access to the AI Control Room Settings area.
- An embedding model available in the AI Model Registry.
- Content (documents or other resources) ready to add to a Knowledge.
How the setup works
Graph RAG comes together in three parts:
- Create a Knowledge: the set of resources to search, plus the rules for how resources are processed.
- Configure its Touchpoint: the model and instructions for answering questions.
- Tune the Graph RAG tool: how broad and how strict the retrieval is. You do the first two once. You return to the third whenever you want to adjust quality.
Create a Knowledge
A Knowledge holds your resources and defines how they are processed when added. Creating one is the first step, because Graph RAG searches a Knowledge.
- Go to Settings → Knowledge and select + New.
- Give the Knowledge a name and an optional description.
- Open the AI Search tab to set up processing.
Set up AI Search
The AI Search tab controls how resources are prepared for retrieval. Configure these in order:
- Turn on Allow AI search. This enables the RAG process for the Knowledge.
- Select an Embedding model. This model converts text into vectors so the system can measure how similar a resource is to a query.
- Choose a Chunking type. Chunking splits each resource into smaller pieces before embedding. See the chunking reference below.
Chunking, embedding, and keyword extraction currently run on textual resources only.
Set up keyword extraction (optional)
Keyword extraction tags each chunk with its most representative terms. Graph RAG uses these terms as an extra signal when ranking results.
- Turn on Allow Keywords Extraction.
- Set the maximum number of entities per chunk.
- Choose an extraction approach:
| Approach | How it works | When to use |
|---|---|---|
| Rule-based | Counts the most frequent terms after cleaning and lemmatizing the text. | Faster, lower precision. |
| LLM-based | A language model reads each chunk and picks the key terms. Uses the Touchpoint's model. | Better quality, slightly slower. |
With the LLM-based approach you can edit the system prompt sent to the model, which helps when terms should be domain-specific.
Configure the Touchpoint
Creating a Knowledge also creates a Touchpoint with default settings, including a working Graph RAG tool. Adjust it in Settings → Touchpoints.
- Conversational Model: the model that writes the answers. Choose from the available models.
- System prompt: the instructions for that model. You can edit the default. By default, the model answers in a set order: it checks the structure of the data, runs a SQL query if the answer is in a database, and falls back to the Graph RAG tool for anything else.
Tune the Graph RAG tool
The Graph RAG tool runs in three phases. Each phase has settings that trade breadth against precision.
Core settings
- Knowledge IDs: the Knowledge bases this tool searches. Select one or more.
- Use Graph Expansion: the master switch for following relationships. Off means a basic semantic search only.
Phase 1: semantic search
The tool first finds resources that match the meaning of the query.
| Setting | What it does | Effect |
|---|---|---|
| Initial Search Limit | How many results to fetch before filtering. | Higher (e.g. 200) widens the pool but adds latency. |
| Semantic Threshold (0.0 to 1.0) | Minimum similarity score to keep a result. | Lower (0.3) = more results; higher (0.7) = more precise. |
Phase 2: graph expansion
The tool takes the strongest Phase 1 results and follows their relationships to find related resources.
| Setting | What it does | Effect |
|---|---|---|
| Graph Expansion Threshold (0.0 to 1.0) | Minimum Phase 1 score for a resource to have its relationships explored. | Keeps low-relevance results from pulling in irrelevant neighbors. |
| Relationship Types | Which kinds of relationships to follow (for example "is part of", "references"). | Leave empty to follow all types. |
| Max Graph Results (minimum 1) | How many related resources to retrieve per starting resource. | Controls breadth and performance. |
Phase 3: final ranking
The tool combines results from both phases, scores them, and fits them into the model's context window. Phase 2 resources get a hybrid score that blends meaning and keyword overlap.
The hybrid score is calculated as:
combined_score = (semanticWeight * semantic_score) + (keywordWeight * keyword_overlap_score)
| Setting | What it does | Effect |
|---|---|---|
| Semantic Weight / Keyword Weight (must add to 1.0) | Balances meaning against exact-term overlap. | High Semantic Weight (0.8) favors topic; high Keyword Weight (0.8) favors matching terms. |
| Keyword Overlap Method | The algorithm for scoring term overlap. | Fuzzy is recommended (handles partial matches and typos). Jaccard, dice, and cosine are also available. |
| Relevance Threshold (0.0 to 1.0) | Final filter for Phase 2 resources. | Only resources at or above this score are kept. |
| Target Context Utilization (0.5 to 0.95) | Share of the context window to fill with retrieved text. | Leave room for the prompts and the model's answer (e.g. 0.9 fills 90%). |
Result
Your Touchpoint can now answer questions using Graph RAG: it finds resources by meaning, expands the search across relationships, and ranks the combined set before answering.
Chunking types reference
Chunking splits a resource into smaller pieces before embedding. Choose the type when you set up AI Search.
| Type | How it splits | Notes |
|---|---|---|
| Semantic Chunker | Detects shifts in meaning using embeddings. | Best retrieval quality, but slower and needs an embedding model. |
| Sentence Chunker | Splits at sentence boundaries, within size limits. | Keeps sentences whole. |
| Token Chunker | Splits into fixed-length token windows. | Simple, size-based. |
| SDPM Chunker | Semantic chunking plus a second pass that merges related chunks. | Preserves context across gaps. |