> ## Documentation Index > Fetch the complete documentation index at: https://docs.blockdb.io/llms.txt > Use this file to discover all available pages before exploring further. # Verify Logs Bloom > Regenerate logs bloom filters for targeted reconciliations. ## Overview Recomputes an Ethereum receipt logs bloom filter from the logs you supply and compares it against an expected bloom (for example, the value published in a block header or receipt). Useful when you only care about log-topic coverage without re-verifying the full receipt trie. ## Parameters Network identifier. Use when the verification workflow should be tied to a specific chain context. *See the [Chain](/api-reference/enumerations/chain) enumeration.* #### Block Context Canonical block height where the log was emitted. Use when the verification workflow should be tied to a specific block height context. 2048-bit bloom filter represented as a 512-character hex string (no `0x` prefix). Typically sourced from a block header or receipt. #### Log Inputs Logs that should populate the bloom filter. Order is irrelevant. Address that emitted the log (hex string, 20 bytes, no `0x` prefix). Encoded into the bloom. 0-4 indexed topics (hex string, 32 bytes each, no `0x` prefix). Each topic contributes to the bloom. Supply an empty array for topic-less logs. #### Pagination Controls Recommended default `250`; maximum `1000` to stay under \~10 MB responses. Pagination cursor from a prior call. ## Response Fields #### Meta Echo of request metadata applied to the response. EVM chain ID echoed from the request when provided; otherwise `null`. #### Data Verification results. Bloom filter supplied in the request. Bloom filter recomputed from `logs`. `true` when `expected_bloom` and `computed_bloom` match bit-for-bit. #### Envelope Fields Number of verification entries returned (currently `1`). ## Use Cases * Sanity-check log ingestion pipelines without fetching receipts or recomputing trie roots. * Confirm that filtered event subscriptions captured all expected topics before downstream processing. * Lightweight guardrail for block producers or relayers to ensure bloom accuracy after custom transformations. ```bash cURL theme={null} curl -X POST "https://api.blockdb.io/v1/evm/verify/logs-bloom" \ -H "Authorization: Bearer $BLOCKDB_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "chain_id": 1, "block_number": 18767124, "expected_bloom": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", "logs": [ { "contract_address": "0000000000000000000000000000000000000000", "topics": [ "ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef", "0000000000000000000000000000000000000000000000000000000000000000" ] } ] }' ``` ```c C theme={null} #include #include #include int main(void) { CURL *curl = curl_easy_init(); if (!curl) return 1; const char *token = getenv("BLOCKDB_API_KEY"); char auth_header[256]; snprintf(auth_header, sizeof(auth_header), "Authorization: Bearer %s", token ? token : ""); const char *payload = "{\"chain_id\":1,\"block_number\":18767124,\"expected_bloom\":\"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000\",\"logs\":[{\"contract_address\":\"0000000000000000000000000000000000000000\",\"topics\":[\"ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef\",\"0000000000000000000000000000000000000000000000000000000000000000\"]}]}"; struct curl_slist *headers = NULL; headers = curl_slist_append(headers, auth_header); headers = curl_slist_append(headers, "Content-Type: application/json"); curl_easy_setopt(curl, CURLOPT_URL, "https://api.blockdb.io/v1/evm/verify/logs-bloom"); curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers); curl_easy_setopt(curl, CURLOPT_POSTFIELDS, payload); CURLcode res = curl_easy_perform(curl); curl_slist_free_all(headers); curl_easy_cleanup(curl); return res == CURLE_OK ? 0 : 1; } ``` ```csharp .NET theme={null} using System; using System.Net.Http; using System.Net.Http.Headers; using System.Text; using System.Threading.Tasks; class Program { static async Task Main() { using var client = new HttpClient(); client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Environment.GetEnvironmentVariable("BLOCKDB_API_KEY")); var payload = new StringContent( "{\"chain_id\":1,\"block_number\":18767124,\"expected_bloom\":\"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000\",\"logs\":[{\"contract_address\":\"0000000000000000000000000000000000000000\",\"topics\":[\"ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef\",\"0000000000000000000000000000000000000000000000000000000000000000\"]}]}", Encoding.UTF8, "application/json" ); var response = await client.PostAsync("https://api.blockdb.io/v1/evm/verify/logs-bloom", payload); response.EnsureSuccessStatusCode(); var body = await response.Content.ReadAsStringAsync(); Console.WriteLine(body); } } ``` ```python Python theme={null} import os import requests response = requests.post( "https://api.blockdb.io/v1/evm/verify/logs-bloom", headers={ "Authorization": f"Bearer {os.getenv('BLOCKDB_API_KEY')}", "Content-Type": "application/json" }, json={'block_number': 18767124, 'chain_id': 1, 'expected_bloom': '00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000', 'logs': [{'contract_address': '0000000000000000000000000000000000000000', 'topics': ['ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef', '0000000000000000000000000000000000000000000000000000000000000000']}]} ) data = response.json() print(data) ``` ```javascript Node.js theme={null} const response = await fetch("https://api.blockdb.io/v1/evm/verify/logs-bloom", { method: "POST", headers: { "Authorization": `Bearer ${process.env.BLOCKDB_API_KEY}`, "Content-Type": "application/json" }, body: JSON.stringify({ "chain_id": 1, "block_number": 18767124, "expected_bloom": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", "logs": [ { "contract_address": "0000000000000000000000000000000000000000", "topics": [ "ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef", "0000000000000000000000000000000000000000000000000000000000000000" ] } ] }) }); const data = await response.json(); console.log(data); ``` ```go Go theme={null} package main import ( "fmt" "net/http" "os" "strings" ) func main() { payload := strings.NewReader(`{ "chain_id": 1, "block_number": 18767124, "expected_bloom": "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", "logs": [ { "contract_address": "0000000000000000000000000000000000000000", "topics": [ "ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef", "0000000000000000000000000000000000000000000000000000000000000000" ] } ] }`) req, _ := http.NewRequest("POST", "https://api.blockdb.io/v1/evm/verify/logs-bloom", payload) req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", os.Getenv("BLOCKDB_API_KEY"))) req.Header.Set("Content-Type", "application/json") client := &http.Client{} resp, _ := client.Do(req) defer resp.Body.Close() // Handle response } ``` ```json 200 theme={null} { "meta": { "chain_id": 1 }, "data": [ { "expected_bloom": "0000…", "computed_bloom": "0000…", "is_identical": true } ], "page_count": 1 } ``` ```json 400 theme={null} { "error": { "code": "BAD_REQUEST", "message": "Invalid request parameters" } } ``` ```json 401 theme={null} { "error": { "code": "UNAUTHORIZED", "message": "Invalid or missing API key" } } ``` ```json 422 theme={null} { "error": { "code": "CHAIN_NOT_SUPPORTED", "http_status": 422, "message": "chain_id=137 is not supported.", "hint": "Use a supported chain_id. Consult the documentation for the list of available chains.", "severity": "error", "retryable": false, "docs_url": "https://docs.blockdb.io/api-reference/overview/error-codes" } } ``` ```json 429 theme={null} { "error": { "code": "RATE_LIMIT_EXCEEDED", "message": "Rate limit exceeded", "details": "Limit: requests/second. Retry after: " } } ``` ```json 503 theme={null} { "error": { "code": "SERVICE_UNAVAILABLE", "http_status": 503, "message": "The service is temporarily unable to handle the request.", "hint": "The database connection pool is briefly saturated. Retry after a short delay.", "severity": "warning", "retryable": true, "details": null, "docs_url": "https://docs.blockdb.io/api-reference/overview/error-codes" } } ```