{"record":{"id":"324fd208a540574b","repo":"mem0ai/mem0","slug":"ids-array-must-be-provided-and-have-the-same-lengt","errorCode":null,"errorMessage":"IDs array must be provided and have the same length as vectors.","messagePattern":"IDs array must be provided and have the same length as vectors\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"mem0-ts/src/oss/src/vector_stores/langchain.ts","lineNumber":64,"sourceCode":"      this.dimension = (this.lcStore as any).embedding.embeddingDimension;\n    }\n    // If still no dimension, we might need to throw or warn, as it's needed for validation\n    if (!this.dimension) {\n      console.warn(\n        \"LangchainVectorStore: Could not determine embedding dimension. Input validation might be skipped.\",\n      );\n    }\n  }\n\n  // --- Method Mappings ---\n\n  async insert(\n    vectors: number[][],\n    ids: string[],\n    payloads: Record<string, any>[],\n  ): Promise<void> {\n    if (!ids || ids.length !== vectors.length) {\n      throw new Error(\n        \"IDs array must be provided and have the same length as vectors.\",\n      );\n    }\n    if (this.dimension) {\n      vectors.forEach((v, i) => {\n        if (v.length !== this.dimension) {\n          throw new Error(\n            `Vector dimension mismatch at index ${i}. Expected ${this.dimension}, got ${v.length}`,\n          );\n        }\n      });\n    }\n\n    // Convert payloads to Langchain Document metadata format\n    const { Document } = await import(\"@langchain/core/documents\");\n    const documents = payloads.map((payload, i) => {\n      // Provide empty pageContent, store mem0 id and other data in metadata\n      return new Document({","sourceCodeStart":46,"sourceCodeEnd":82,"githubUrl":"https://github.com/mem0ai/mem0/blob/001c235229be8795e3834520467bd0d661ed8f34/mem0-ts/src/oss/src/vector_stores/langchain.ts#L46-L82","documentation":"insert() in the Langchain adapter throws when the ids array is missing or its length differs from the vectors array length. Each mem0 memory id must be attached to its vector as document metadata (_mem0_id), so a 1:1 correspondence is mandatory before documents are built.","triggerScenarios":"Calling store.insert(vectors, ids, payloads) where ids is undefined, shorter, or longer than vectors — typically from a custom pipeline or a mis-sliced batch where vectors/ids were sliced inconsistently.","commonSituations":"Custom callers slicing batches of vectors and ids with different offsets; forgetting to generate ids for a new batch; passing payloads.length vectors but a deduplicated ids array.","solutions":["Generate one id per vector before calling insert (e.g. ids = vectors.map(() => crypto.randomUUID())).","When batching, slice vectors, ids, and payloads with the same range so lengths stay equal.","Add an assertion in calling code: vectors.length === ids.length === payloads.length."],"exampleFix":"// before\nawait store.insert(vectors.slice(0, 10), ids, payloads.slice(0, 10));\n\n// after\nawait store.insert(\n  vectors.slice(0, 10),\n  ids.slice(0, 10),\n  payloads.slice(0, 10),\n);","handlingStrategy":"validation","validationCode":"if (!Array.isArray(ids) || ids.length !== vectors.length || payloads.length !== vectors.length) {\n  throw new Error(`Length mismatch: vectors=${vectors.length} ids=${ids?.length} payloads=${payloads.length}`);\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Always generate one id per vector before insert.","When batching, slice vectors, ids, and payloads with identical ranges.","Assert equal lengths in calling code as a cheap precondition."],"tags":["langchain","insert","validation","vector-store","typescript"],"backgroundTag":null,"analyzedSha":"001c235229be8795e3834520467bd0d661ed8f34","analyzedAt":"2026-08-15T01:55:42.685Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}