deepseek-ai/deepseek-harness · error

conversation Context ${key} received more than one start Mat

Error message

conversation Context ${key} received more than one start Match

What it means

Error "conversation Context ${key} received more than one start Match" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/client/runtime/src/client/sessions/conversation-assembler.ts:396

    if (fallback !== undefined && target !== undefined && !matchedTargets.has(target)) {
      const result = fallback.match(input.event)
      if (result !== null) {
        publication = maximumPublication(publication, accept(fallback, result.id, result.role))
      }
    }
    return publication
  }

  private acceptMatch(
    definition: ConversationNodeDefinition,
    id: string,
    role: ConversationMatch['role'],
    input: ConversationEventInput,
  ): ConversationPublication {
    const key = conversationContextKey(definition.kind, id)
    let context = this.contexts.get(key)
    if (role === 'start' && context?.start !== undefined) {
      throw new Error(`conversation Context ${key} received more than one start Match`)
    }
    if (context === undefined) {
      context = {
        key,
        kind: definition.kind,
        id,
        definition,
        startSeq: undefined,
        start: undefined,
        matches: [],
        state: undefined,
        revision: 0,
        current: new Map(),
        locationData: emptyLocationData(),
        dependencies: new Map(),
      }
      this.contexts.set(key, context)
    }

View on GitHub (pinned to b150a551b8)

Solutions

1. Emit only one start Match per Context.

When it happens

Trigger: Thrown at packages/client/runtime/src/client/sessions/conversation-assembler.ts:396 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/055ccf6467a34f52. Report an issue: GitHub.