Feature/AWS Bedrock Knowledge Bases retriever (#2905)

* AWS Bedrock Knowledge bases retriever added

* Moved @langchain/aws from root dependency to overrides

* pnpm-lock.yaml update

---------

Co-authored-by: Rok Pajk Kosec <rok.pajkkosec@gmail.com>

package.json

@@ -58,7 +58,8 @@
             "sqlite3"
         ],
         "overrides": {
-            "@langchain/core": "0.2.18"
+            "@langchain/core": "0.2.18",
+            "@langchain/aws": "^0.0.6"
         }
     },
     "engines": {

packages/components/nodes/retrievers/AWSBedrockKBRetriever/AWSBedrockKBRetriever.ts

@@ -0,0 +1,143 @@
+import { AmazonKnowledgeBaseRetriever } from '@langchain/aws'
+import { ICommonObject, INode, INodeData, INodeParams, INodeOptionsValue } from '../../../src/Interface'
+import { getCredentialData, getCredentialParam } from '../../../src/utils'
+import { RetrievalFilter } from '@aws-sdk/client-bedrock-agent-runtime'
+import { MODEL_TYPE, getRegions } from '../../../src/modelLoader'
+
+class AWSBedrockKBRetriever_Retrievers implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    credential: INodeParams
+    inputs: INodeParams[]
+    badge: string
+
+    constructor() {
+        this.label = 'AWS Bedrock Knowledge Base Retriever'
+        this.name = 'awsBedrockKBRetriever'
+        this.version = 1.0
+        this.type = 'AWSBedrockKBRetriever'
+        this.icon = 'AWSBedrockKBRetriever.svg'
+        this.category = 'Retrievers'
+        this.badge = 'NEW'
+        this.description = 'Connect to AWS Bedrock Knowledge Base API and retrieve relevant chunks'
+        this.baseClasses = [this.type, 'BaseRetriever']
+        this.credential = {
+            label: 'AWS Credential',
+            name: 'credential',
+            type: 'credential',
+            credentialNames: ['awsApi'],
+            optional: true
+        }
+        this.inputs = [
+            {
+                label: 'Region',
+                name: 'region',
+                type: 'asyncOptions',
+                loadMethod: 'listRegions',
+                default: 'us-east-1'
+            },
+            {
+                label: 'Knowledge Base ID',
+                name: 'knoledgeBaseID',
+                type: 'string'
+            },
+            {
+                label: 'Query',
+                name: 'query',
+                type: 'string',
+                description: 'Query to retrieve documents from retriever. If not specified, user question will be used',
+                optional: true,
+                acceptVariable: true
+            },
+            {
+                label: 'TopK',
+                name: 'topK',
+                type: 'number',
+                description: 'Number of chunks to retrieve',
+                optional: true,
+                additionalParams: true,
+                default: 5
+            },
+            {
+                label: 'SearchType',
+                name: 'searchType',
+                type: 'options',
+                description:
+                    'Knowledge Base search type. Possible values are HYBRID and SEMANTIC. If not specified, default will be used. Consult AWS documentation for more',
+                options: [
+                    {
+                        label: 'HYBRID',
+                        name: 'HYBRID',
+                        description: 'Hybrid seach type'
+                    },
+                    {
+                        label: 'SEMANTIC',
+                        name: 'SEMANTIC',
+                        description: 'Semantic seach type'
+                    }
+                ],
+                optional: true,
+                additionalParams: true,
+                default: undefined
+            },
+            {
+                label: 'Filter',
+                name: 'filter',
+                type: 'string',
+                description: 'Knowledge Base retrieval filter. Read documentation for filter syntax',
+                optional: true,
+                additionalParams: true
+            }
+        ]
+    }
+
+    loadMethods = {
+        // Reuse the AWS Bedrock Embeddings region list as it should be same for all Bedrock functions
+        async listRegions(): Promise<INodeOptionsValue[]> {
+            return await getRegions(MODEL_TYPE.EMBEDDING, 'AWSBedrockEmbeddings')
+        }
+    }
+
+    async init(nodeData: INodeData, input: string, options: ICommonObject): Promise<any> {
+        const knoledgeBaseID = nodeData.inputs?.knoledgeBaseID as string
+        const region = nodeData.inputs?.region as string
+        const topK = nodeData.inputs?.topK as number
+        const overrideSearchType = (nodeData.inputs?.searchType != '' ? nodeData.inputs?.searchType : undefined) as 'HYBRID' | 'SEMANTIC'
+        const filter = (nodeData.inputs?.filter != '' ? JSON.parse(nodeData.inputs?.filter) : undefined) as RetrievalFilter
+        let credentialApiKey = ''
+        let credentialApiSecret = ''
+        let credentialApiSession = ''
+
+        const credentialData = await getCredentialData(nodeData.credential ?? '', options)
+        if (credentialData && Object.keys(credentialData).length !== 0) {
+            credentialApiKey = getCredentialParam('awsKey', credentialData, nodeData)
+            credentialApiSecret = getCredentialParam('awsSecret', credentialData, nodeData)
+            credentialApiSession = getCredentialParam('awsSession', credentialData, nodeData)
+        }
+
+        const retriever = new AmazonKnowledgeBaseRetriever({
+            topK: topK,
+            knowledgeBaseId: knoledgeBaseID,
+            region: region,
+            filter,
+            overrideSearchType,
+            clientOptions: {
+                credentials: {
+                    accessKeyId: credentialApiKey,
+                    secretAccessKey: credentialApiSecret,
+                    sessionToken: credentialApiSession
+                }
+            }
+        })
+
+        return retriever
+    }
+}
+
+module.exports = { nodeClass: AWSBedrockKBRetriever_Retrievers }