Compression Retriever - Cohere Rerank

2026-06-28 09:00:52 +03:00 · 2023-12-22 12:12:04 +05:30
parent 56b043264a
commit 94236c4b5f
3 changed files with 135 additions and 0 deletions
@@ -0,0 +1,51 @@
+import { Callbacks } from 'langchain/callbacks'
+import { Document } from 'langchain/document'
+import { BaseDocumentCompressor } from 'langchain/retrievers/document_compressors'
+import axios from 'axios'
+export class CohereRerank extends BaseDocumentCompressor {
+    private cohereAPIKey: any
+    private COHERE_API_URL = 'https://api.cohere.ai/v1/rerank'
+    private model: string
+
+    constructor(cohereAPIKey: string, model: string) {
+        super()
+        this.cohereAPIKey = cohereAPIKey
+        this.model = model
+    }
+    async compressDocuments(
+        documents: Document<Record<string, any>>[],
+        query: string,
+        _?: Callbacks | undefined
+    ): Promise<Document<Record<string, any>>[]> {
+        // avoid empty api call
+        if (documents.length === 0) {
+            return []
+        }
+        const config = {
+            headers: {
+                Authorization: `Bearer ${this.cohereAPIKey}`,
+                'Content-Type': 'application/json',
+                Accept: 'application/json'
+            }
+        }
+        const data = {
+            model: this.model,
+            max_chunks_per_doc: 10,
+            query: query,
+            return_documents: false,
+            documents: documents.map((doc) => doc.pageContent)
+        }
+        try {
+            let returnedDocs = await axios.post(this.COHERE_API_URL, data, config)
+            const finalResults: Document<Record<string, any>>[] = []
+            returnedDocs.data.results.forEach((result: any) => {
+                const doc = documents[result.index]
+                doc.metadata.relevance_score = result.relevance_score
+                finalResults.push(doc)
+            })
+            return finalResults
+        } catch (error) {
+            return documents
+        }
+    }
+}
@@ -0,0 +1,77 @@
+import { ICommonObject, INode, INodeData, INodeOutputsValue, INodeParams } from '../../../src/Interface'
+import { BaseRetriever } from 'langchain/schema/retriever'
+import { ContextualCompressionRetriever } from 'langchain/retrievers/contextual_compression'
+import { getCredentialData, getCredentialParam } from '../../../src'
+import { CohereRerank } from './CohereRerank'
+
+class CohereRerankRetriever_Retrievers implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    inputs: INodeParams[]
+    outputs: INodeOutputsValue[]
+    credential: INodeParams
+    badge: string
+
+    constructor() {
+        this.label = 'Cohere Rerank Retriever'
+        this.name = 'cohereRerankRetriever'
+        this.version = 1.0
+        this.type = 'Cohere Rerank Retriever'
+        this.icon = 'compressionRetriever.svg'
+        this.category = 'Retrievers'
+        this.badge = 'NEW'
+        this.description = 'Cohere Rerank indexes the documents from most to least semantically relevant to the query.'
+        this.baseClasses = [this.type, 'BaseRetriever']
+        this.credential = {
+            label: 'Connect Credential',
+            name: 'credential',
+            type: 'credential',
+            credentialNames: ['cohereApi']
+        }
+        this.inputs = [
+            {
+                label: 'Base Retriever',
+                name: 'baseRetriever',
+                type: 'VectorStoreRetriever'
+            },
+            {
+                label: 'Model Name',
+                name: 'model',
+                type: 'options',
+                options: [
+                    {
+                        label: 'rerank-english-v2.0',
+                        name: 'rerank-english-v2.0'
+                    },
+                    {
+                        label: 'rerank-multilingual-v2.0',
+                        name: 'rerank-multilingual-v2.0'
+                    }
+                ],
+                default: 'rerank-english-v2.0',
+                optional: true
+            }
+        ]
+    }
+
+    async init(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
+        const baseRetriever = nodeData.inputs?.baseRetriever as BaseRetriever
+        const model = nodeData.inputs?.model as string
+        const credentialData = await getCredentialData(nodeData.credential ?? '', options)
+        const cohereApiKey = getCredentialParam('cohereApiKey', credentialData, nodeData)
+
+        const cohereCompressor = new CohereRerank(cohereApiKey, model)
+        return new ContextualCompressionRetriever({
+            baseCompressor: cohereCompressor,
+            baseRetriever: baseRetriever
+        })
+    }
+}
+
+module.exports = { nodeClass: CohereRerankRetriever_Retrievers }
@@ -0,0 +1,7 @@
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