{"record":{"id":"9fca813db2c9eb77","repo":"nautechsystems/nautilus_trader","slug":"failed-to-register-dex-exchange-e-9fca81","errorCode":null,"errorMessage":"Failed to register DEX exchange: {e}","messagePattern":"Failed to register DEX exchange: (.+?)","errorType":"exception","errorClass":"anyhow::Error","httpStatus":null,"severity":"error","filePath":"crates/cli/src/blockchain/sync.rs","lineNumber":115,"sourceCode":"    log::info!(\"Using RPC HTTP URL: '{masked_url}'\");\n\n    let config = BlockchainDataClientConfig::builder()\n        .chain(Arc::new(chain.to_owned()))\n        .dex_ids(vec![dex_type])\n        .http_rpc_url(rpc_http_url.into())\n        .maybe_multicall_calls_per_rpc_request(multicall_calls_per_rpc_request)\n        .use_hypersync_for_live_data(true)\n        .postgres_cache_database_config(postgres_connect_options)\n        .build();\n    let cancellation_token = tokio_util::sync::CancellationToken::new();\n    let mut data_client = BlockchainDataClientCore::new(config, None, None, cancellation_token);\n    data_client.initialize_cache_database().await;\n\n    data_client.cache.initialize_chain().await;\n    data_client\n        .register_dex_exchange(dex_type)\n        .await\n        .map_err(|e| anyhow::anyhow!(\"Failed to register DEX exchange: {e}\"))?;\n    // We want to have full pool sync, so from 0 to last.\n    data_client\n        .sync_exchange_pools(&dex_type, 0, None, reset)\n        .await\n        .map_err(|e| anyhow::anyhow!(\"Failed to sync pools: {e}\"))?;\n\n    Ok(())\n}\n\npub(crate) async fn run_sync_blocks(\n    chain: String,\n    from_block: Option<u64>,\n    to_block: Option<u64>,\n    database: DatabaseConfig,\n) -> anyhow::Result<()> {\n    let chain = Chain::from_chain_name(&chain)\n        .ok_or_else(|| anyhow::anyhow!(\"Invalid chain name: {chain}\"))?;\n    let chain = Arc::new(chain.to_owned());","sourceCodeStart":97,"sourceCodeEnd":133,"githubUrl":"https://github.com/nautechsystems/nautilus_trader/blob/18893faf8b356be3320add8de2f861b0b647cf06/crates/cli/src/blockchain/sync.rs#L97-L133","documentation":"Wraps any error returned by `BlockchainDataClientCore::register_dex_exchange` when the `sync dex` CLI command tries to register a DEX (e.g. Uniswap-v3) on the blockchain data client. Registration involves on-chain contract resolution and cache/database setup over the node RPC, so any RPC, network, unsupported-DEX, or database failure surfaces here under this message. The CLI aborts the whole sync via `?`.","triggerScenarios":"Calling `nautilus blockchain sync dex` (run_sync_dex) where the underlying node RPC is unreachable or errors, the configured provider URL/chain is wrong, the dex_type is not supported by the adapter, or the cache database cannot be initialized for the exchange.","commonSituations":"Running against a local Ethereum node that is not started or not synced; pointing at a chain that does not host the DEX; typos in the DEX name argument; Postgres/cache not reachable; RPC rate limits or timeouts during factory/contract lookups.","solutions":["Verify the node RPC endpoint is running, reachable, and fully synced before retrying.","Check the dex_type argument matches a DEX supported by the blockchain adapter (e.g. exact name/casing expected by the adapter).","Confirm the --chain value matches the chain the node is connected to and that the DEX is deployed there.","Check the cache/Postgres database config is correct and the database is reachable.","Run with RUST_LOG=debug to see the underlying error embedded in `{e}` and address it directly."],"exampleFix":"// before\n\"sync dex --dex-type uniswapv2 --chain arbitrum\"   # node on mainnet, chain mismatch\n// after\n\"sync dex --dex-type uniswap-v3 --chain ethereum --url http://localhost:8545\"","handlingStrategy":"try-catch","validationCode":"// before running: check node reachability\nlet status = reqwest::get(format!(\"{url}/health\")).await;\nassert!(status.is_ok(), \"node RPC unreachable at {url}\");\n// and confirm dex_type is one the adapter supports","typeGuard":null,"tryCatchPattern":"match run_sync_dex(...).await {\n    Ok(()) => info!(\"DEX exchange registered\"),\n    Err(e) if e.to_string().contains(\"Failed to register DEX exchange\") => {\n        eprintln!(\"RPC/registration failed: {e:#}; check node URL, dex_type, and DB config\");\n    }\n    Err(e) => return Err(e),\n}","preventionTips":["Health-check the node RPC endpoint before launching the sync.","Validate dex_type and chain against the adapter's supported values before invoking.","Keep Postgres/cache credentials in env/config and verify connectivity at startup.","Use a dedicated or local node rather than rate-limited public endpoints for registration + full syncs.","Log the inner error chain ({e:#}) to distinguish RPC vs DB causes."],"tags":["cli","blockchain","network","rpc"],"backgroundTag":"api-request-failed","analyzedSha":"18893faf8b356be3320add8de2f861b0b647cf06","analyzedAt":"2026-09-08T20:49:34.690Z","contentChangedAt":"2026-09-08T20:49:34.690Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}