{"record":{"id":"7ec632d086515a6d","repo":"clockworklabs/SpacetimeDB","slug":"call-http-handler-dunder-returned-unexpected-cod","errorCode":null,"errorMessage":"{CALL_HTTP_HANDLER_DUNDER} returned unexpected code {code}. HTTP handlers should return code 0 or trap.","messagePattern":"(.+?) returned unexpected code (.+?)\\. HTTP handlers should return code 0 or trap\\.","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/core/src/host/wasmtime/wasmtime_module.rs","lineNumber":882,"sourceCode":"                    op.timestamp.to_micros_since_unix_epoch() as u64,\n                    request_source.0,\n                    request_body_source.0,\n                    response_sink,\n                    response_body_sink,\n                ),\n            )\n            .await;\n\n        store.data_mut().terminate_dangling_anon_tx();\n\n        let (stats, result_bytes, response_body_bytes) =\n            finish_http_handler_opcall(store, budget, response_sink, response_body_sink);\n\n        let call_result = call_result.and_then(|code| {\n            (code == 0)\n                .then_some((result_bytes.into(), response_body_bytes.into()))\n                .ok_or_else(|| {\n                anyhow::anyhow!(\n                    \"{CALL_HTTP_HANDLER_DUNDER} returned unexpected code {code}. HTTP handlers should return code 0 or trap.\"\n                )\n                })\n        });\n\n        let res = module_host_actor::HttpHandlerExecuteResult { stats, call_result };\n\n        let tx_offset = store.data_mut().take_procedure_tx_offset();\n\n        (res, tx_offset)\n    }\n}\n\nfn set_store_fuel(store: &mut impl AsContextMut, fuel: WasmtimeFuel) {\n    store.as_context_mut().set_fuel(fuel.0).unwrap();\n}\n\nfn get_store_fuel(store: &impl AsContext) -> WasmtimeFuel {","sourceCodeStart":864,"sourceCodeEnd":900,"githubUrl":"https://github.com/clockworklabs/SpacetimeDB/blob/524b4487d949b61a07d4f39c862d1290259dfd20/crates/core/src/host/wasmtime/wasmtime_module.rs#L864-L900","documentation":"Error \"{CALL_HTTP_HANDLER_DUNDER} returned unexpected code {code}. HTTP handlers should return code 0 or trap.\" thrown in clockworklabs/SpacetimeDB.","triggerScenarios":"Thrown at crates/core/src/host/wasmtime/wasmtime_module.rs:882 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"524b4487d949b61a07d4f39c862d1290259dfd20","analyzedAt":"2026-08-16T23:58:54.611Z","schemaVersion":2},"datasetVersion":"2026-08-17T04:17:16.089Z"}