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Search Knowledge Base

Search a knowledge base with an AI research agent and return the findings and answer

Action Data & Storage v1

Search Knowledge Base sends an AI research subagent into a knowledge base and returns what it found: per-document findings with the extracted content and a confidence level, a written answer to the query, and a summary of how the search was conducted. A typical build is answering support questions from internal documentation with the sources attached.

Node type
Action
Parameters
10
Outputs
Output, Error
Credentials
None required

Search Knowledge Base

AI search over a knowledge base

Overview

Runs an agentic search over a BusyBot knowledge base. A search subagent greps, reads and semantically analyzes the knowledge base documents, records evidence, and returns findings (per-document extracted content with confidence), a written answer to the query, and a summary of how the search was conducted. Supports a fast mode (up to 20 iterations) and a deep-research mode (40 iterations across 8 phases).

Category: Data & Storage
Tool Name: search_knowledge_base
Version: 1

Appearance: Icon: lucide-ScanSearch | Color: #7C3AED

Node Type

Action — processes input items and produces output

Input / Output

DirectionPort(s)
InputInput
OutputOutput, Error

Credentials

This tool does not require any credentials.

Parameters

ParameterTypeRequiredDefaultDescription
Knowledge BasestringYesThe knowledge base ID or its exact name. Supports expressions like {{ $json.kbId }}.
QuerystringYesWhat to find, in natural language. A full question works far better than keywords. Supports expressions.
ModeoptionsNoquickHow thoroughly to search.
Options: quick (free-form search, up to 20 iterations — the engine agent chat uses), deep (40 iterations across 8 gated research phases; slow and expensive, best for background runs)
Max IterationsnumberNo20Quick mode only — upper bound on search iterations. Deep mode always runs its 40-iteration phase plan. (shown when Mode is quick)
Output ModeoptionsNosingleHow to shape the output items.
Options: single (one output item per input item, findings nested in an array), perFinding (fan out — one output item per finding)
Include FindingsbooleanNotrueInclude per-document extracted content. Turn off to return only the answer and summary. (shown when Output Mode is single)
Include Search StepsbooleanNofalseInclude the step-by-step trace of what the search agent did (useful for debugging a disappointing answer).
Fail If Nothing FoundbooleanNofalseTreat a search that returns no findings as an item error instead of a normal result.
Max ConcurrencynumberNo2Searches running at once. Each is a full LLM agent loop — keep this low.

Output Data

One search per input item. Results are written to kbSearch on the output item; the rest of the item JSON passes through unchanged, and binary data is forwarded.

{
  "kbId": "kb_...", "kbName": "Product Manuals", "query": "...", "mode": "quick",
  "answer": "The direct answer synthesized from the findings",
  "searchSummary": "What was searched, which documents were examined, how the answer was reached",
  "findings": [{ "docId": "doc_...", "fileName": "manual.pdf", "relevantContent": "the actual extracted text", "confidence": "high" }],
  "findingCount": 3, "iterations": 6, "exitReason": "model",
  "documentsInKb": 42, "stale": false, "healthy": true, "durationMs": 18420
}
  • exitReason: model (the agent finished on its own — the good case), cap (hit the iteration limit), stall (repeated itself and was cut short), phased (deep mode ran its full course).
  • stale: true means documents changed since the knowledge base summary was regenerated; results may not reflect the latest content.
  • findings is present in single output mode when Include Findings is on. In perFinding mode the node fans out instead: one output item per finding, each carrying finding and findingIndex with the answer and summary repeated. A search with no findings still emits one item, with finding: null.
  • steps is added when Include Search Steps is on, and phasesVisited when Mode is deep.

Reference the result downstream by expression, e.g. {{ $json.kbSearch.answer }}.

Usage Examples

  • search the knowledge base for the payment terms
  • ask my knowledge base what the maintenance interval is
  • do deep research across the knowledge base on data retention commitments
  • find every document mentioning the vendor and quote the relevant lines

Example Configuration

Answer a question from a knowledge base:

{
  "type": "search_knowledge_base",
  "parameters": {
    "knowledgeBase": "Product Manuals",
    "query": "What is the recommended maintenance interval for the {{ $json.model }} pump?",
    "mode": "quick"
  }
}

Deep background research, fanned out one item per finding:

{
  "type": "search_knowledge_base",
  "parameters": {
    "knowledgeBase": "kb_1765432100000_ab12cd34",
    "query": "Every commitment we made about data retention, with the document it came from",
    "mode": "deep",
    "outputMode": "perFinding",
    "includeSteps": true
  }
}

Error Handling

ModeBehavior
stopHalts workflow on first error
continueSkips failed items, passes successful ones through
errorPortRoutes failed items to Error output port

Tips

Searches a knowledge base with an AI research subagent and returns what it found: per-document findings with the actual extracted content and a confidence level, a written answer to the query, and a summary of how the search was run. Use quick mode for normal lookups and deep mode for exhaustive background research — deep runs 40 phased iterations (map, synonym expansion, semantic deep-read, cross-checking, gap analysis, verification, synthesis) and costs substantially more time and tokens. Point it at a knowledge base by ID or name and give it a natural-language question rather than keywords.

Choosing a mode

  • quick — the default. Typical searches finish in 3–8 iterations. Use for lookups, enrichment inside a live pipeline, and anything a person is waiting on.
  • deep — a scheduled/background research job over a large or high-stakes corpus: exhaustive enumeration, “is X mentioned anywhere”, contradiction hunting, or literature-style review. It always runs its phases and can take many minutes.

Behavior notes

  • The knowledge base must be ready (ingested). Searching an empty or still-processing KB errors.
  • The content bundle is downloaded once per knowledge base per node run and shared by every item targeting it, then deleted.
  • Cost is real: llm_search sends document text to a model, and deep mode is designed to spend iterations. Prefer quick mode plus a narrow query.

Frequently asked questions

What is the difference between quick and deep mode?

Quick suits normal lookups. Deep runs 40 phased iterations — mapping, synonym expansion, semantic deep-read, cross-checking, gap analysis, verification and synthesis — and costs substantially more time and tokens, so it belongs in background research rather than interactive paths.

What does it return besides an answer?

Per-document findings containing the actual extracted content with a confidence level, plus a summary of how the search was run — so an answer can be checked rather than trusted blindly.

Does it need credentials?

No. Knowledge bases belong to the workflow's owner, so the node resolves the user from the run itself.

How do I get content into the knowledge base?

With the Knowledge Base node, which adds, replaces and removes documents from a workflow.

Build with the Search Knowledge Base node

Drop it into a workflow, wire it to an agent, or call it on a schedule.

Open BusyBot

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