mem0ai/mem0 · error · Error

S3 Vectors does not support '${operator}' metadata filters.

Error message

S3 Vectors does not support '${operator}' metadata filters.

What it means

The S3 Vectors vector store in mem0-ts throws this when converting a user-supplied metadata filter that uses the 'contains', 'icontains', or 'startsWith' operators. AWS S3 Vectors only supports equality, comparison, in/nin, and exists semantics on metadata, so substring matching cannot be pushed down to the service. The store fails fast at filter-conversion time instead of silently returning wrong results.

Source

Thrown at mem0-ts/src/oss/src/vector_stores/s3_vectors.ts:636

        case "lte":
          operators.$lte = operand;
          break;
        case "in":
          if (!Array.isArray(operand) || operand.length === 0) {
            return { [ALWAYS_FALSE_FILTER_KEY]: true };
          }
          operators.$in = operand;
          break;
        case "nin":
          if (!Array.isArray(operand) || operand.length === 0) {
            break;
          }
          operators.$nin = operand;
          break;
        case "contains":
        case "icontains":
        case "startsWith":
          throw new Error(
            `S3 Vectors does not support '${operator}' metadata filters.`,
          );
        default:
          throw new Error(
            `Unsupported S3 Vectors filter operator: ${operator}`,
          );
      }
    }

    if (Object.keys(operators).length === 0) {
      return {};
    }
    return { [key]: operators };
  }

  private negateFilter(filter: S3Filter): S3Filter {
    if (Array.isArray(filter.$and)) {
      return {

View on GitHub (pinned to 001c235229)

Solutions

1. Rewrite the filter using supported operators: in/nin for value sets, eq/ne for exact matches, gte/lte/gt/lt for ranges, exists for presence.
2. Do substring matching client-side: search with the broadest safe filter (e.g. eq on user_id) and post-filter the returned payloads in your code.
3. If substring search on metadata is a hard requirement, switch to a vector store that supports it (e.g. Qdrant, Chroma) via the vectorStore config.

Example fix

// before
await memory.search("notes", { filters: { user_id: { contains: "alice" } } });

// after
const results = await memory.search("notes", { filters: { user_id: { eq: "alice-123" } } });

const S3_UNSUPPORTED = new Set(["contains", "icontains", "startsWith"]);
function assertS3SafeFilter(filters: any): void {
  for (const [k, v] of Object.entries(filters ?? {})) {
    if (["AND", "OR", "NOT"].includes(k)) { (v as any[]).forEach(assertS3SafeFilter); continue; }
    if (v && typeof v === "object" && !Array.isArray(v))
      for (const op of Object.keys(v))
        if (S3_UNSUPPORTED.has(op)) throw new Error(`Filter operator '${op}' unsupported on S3 Vectors; rewrite as in/eq`);
  }
}
assertS3SafeFilter(myFilters);

function isS3SafeOperator(op: string): op is 'eq'|'ne'|'gt'|'gte'|'lt'|'lte'|'in'|'nin' {
  return ['eq','ne','gt','gte','lt','lte','in','nin'].includes(op);
}

try { await memory.search(q, { filters }); } catch (e) { if (e instanceof Error && e.message.includes('does not support') && e.message.includes('metadata filters')) { /* fall back to eq filter + client-side substring */ } else throw e; }

When it happens

Trigger: Calling memory.search(query, { filters: { user_id: { contains: 'alice' } } }) or any filter using contains/icontains/startsWith while vectorStore is configured as S3Vectors. Also triggered when an LLM-derived filter or upstream code constructs those operators generically across vector stores.

Common situations: Porting an app from Qdrant/Chroma (which support substring filters) to S3 Vectors; sharing filter-building code across multiple store backends; agent pipelines that auto-generate filters with string-matching operators.

Related errors

• Unsupported S3 Vectors filter operator: ${operator}
• S3 Vectors cannot negate this filter shape.
• Top-level entity parameters [${invalidKeys.join(", ")}] are
• Invalid ${name}: cannot be empty or whitespace-only. Provide
• Invalid ${name}: cannot contain whitespace. Provide a valid

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/ff91d98eb8402cfc. Report an issue: GitHub.