{"record":{"id":"fadc4bfe2813f760","repo":"deepseek-ai/deepseek-harness","slug":"conversation-context-key-received-non-appended","errorCode":null,"errorMessage":"conversation Context ${key} received non-appended Match ${input.event.seq}","messagePattern":"conversation Context (.+?) received non-appended Match (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/client/runtime/src/client/sessions/conversation-assembler.ts","lineNumber":422,"sourceCode":"        startSeq: undefined,\n        start: undefined,\n        matches: [],\n        state: undefined,\n        revision: 0,\n        current: new Map(),\n        locationData: emptyLocationData(),\n        dependencies: new Map(),\n      }\n      this.contexts.set(key, context)\n    }\n    const match: ConversationMatch = {\n      ...input,\n      role,\n      location: this.locationIndex.locationOf(input.event),\n    }\n    const previous = context.matches.at(-1)\n    if (previous !== undefined && previous.event.seq >= input.event.seq) {\n      throw new Error(`conversation Context ${key} received non-appended Match ${input.event.seq}`)\n    }\n    if (role === 'start' && context.matches.length > 0) {\n      throw new Error(`conversation Context ${key} received an update before its start Match`)\n    }\n    context.matches.push(match)\n    if (role === 'start') {\n      context.startSeq = input.event.seq\n      context.start = match\n      this.indexStartedContext(context)\n    }\n    const owners = this.contextsBySeq.get(input.event.seq) ?? new Set<InternalContext>()\n    owners.add(context)\n    this.contextsBySeq.set(input.event.seq, owners)\n\n    if (role === 'start') {\n      this.replayContext(context)\n    } else if (context.state !== undefined) {\n      const typed = contextSnapshot(context) as ConversationNodeContext & { readonly state: unknown }","sourceCodeStart":404,"sourceCodeEnd":440,"githubUrl":"https://github.com/deepseek-ai/deepseek-harness/blob/b150a551b8d465e31e418e1b2eaf5e79bbb7d28e/packages/client/runtime/src/client/sessions/conversation-assembler.ts#L404-L440","documentation":"Error \"conversation Context ${key} received non-appended Match ${input.event.seq}\" thrown in deepseek-ai/deepseek-harness.","triggerScenarios":"Thrown at packages/client/runtime/src/client/sessions/conversation-assembler.ts:422 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Append events in seq order; do not deliver a non-appended Match."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"b150a551b8d465e31e418e1b2eaf5e79bbb7d28e","analyzedAt":"2026-08-24T18:12:29.105Z","schemaVersion":2},"datasetVersion":"2026-08-24T22:17:12.610Z"}