deepseek-ai/deepseek-harness · error · Error

session event seq ${event.seq} is not contiguous; expected $

Error message

session event seq ${event.seq} is not contiguous; expected ${expectedSeq}

What it means

Error "session event seq ${event.seq} is not contiguous; expected ${expectedSeq}" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/core/session/src/surface.ts:329

      ...event.data.message,
      content: [{ ...replacementResult, content: null }],
    }
    if (!isDeepEqualJson(originalRest, replacementRest)) {
      throw new Error('tool/result surface replacement may change only content')
    }
  }
}

/** Validate one event at its replay boundary and prepare its atomic fold transition. */
function planSurfaceEvent(
  state: SurfaceFoldState,
  event: SessionEvent,
  expectedSeq: number,
  events: readonly SessionEvent[],
  baseSeq: number,
): SurfacePlan | undefined {
  if (event.seq !== expectedSeq) {
    throw new Error(`session event seq ${event.seq} is not contiguous; expected ${expectedSeq}`)
  }
  const surfaceOp = surfaceOpOf(event)
  if (surfaceOp === undefined) return
  if (surfaceOp === 'append') {
    assertProvenance(event, [])
    return { kind: 'append', seq: event.seq }
  }
  const range = replacementRange(state, surfaceOp)
  assertProvenance(event, range.shadowedSeqs)
  assertToolResultRewrite(event, range.shadowedSeqs, events, baseSeq)
  return {
    kind: 'replace',
    seq: event.seq,
    start: surfaceOp.start,
    end: surfaceOp.end,
    ...range,
  }
}

View on GitHub (pinned to b150a551b8)

When it happens

Trigger: Thrown at packages/core/session/src/surface.ts:329 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/273a525819b6e904. Report an issue: GitHub.