deepseek-ai/deepseek-harness · error · Error

seed request/header at index ${index} has invalid adapterDef

Error message

seed request/header at index ${index} has invalid adapterDefaults

What it means

Error "seed request/header at index ${index} has invalid adapterDefaults" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/core/session/src/index.ts:289

    assertAdapterDefaults(headerRecord?.['adapterDefaults'], configRecord, index)
  }
  const type = event['type']
  if (type !== 'user/message' && type !== 'assistant/message'
    && type !== 'tool/result') return
  assertMessageEventShape(event, `seed ${type} at index ${index}`)
}

const allowedAdapterKeys = new Set(['reasoningEffort', 'maxTokens'])

/** Validate adapter-default markers imported from a durable request header. */
function assertAdapterDefaults(
  value: unknown,
  config: Record<string, unknown>,
  index: number,
): void {
  if (value === undefined) return
  if (typeof value !== 'object' || value === null || Array.isArray(value)) {
    throw new Error(`seed request/header at index ${index} has invalid adapterDefaults`)
  }
  const defaults = value as Record<string, unknown>
  if (Object.keys(defaults).some(key => !allowedAdapterKeys.has(key))
    || Object.values(defaults).some(marker => marker !== true)
    || defaults['reasoningEffort'] === true && config['reasoningEffort'] === undefined
    || defaults['maxTokens'] === true && config['maxTokens'] === undefined) {
    throw new Error(`seed request/header at index ${index} has invalid adapterDefaults`)
  }
}

/** Validate only the event-specific invariants needed to safely replay a message. */
function assertMessageEventShape(event: Record<string, unknown>, subject: string): void {
  const type = event['type']
  if (type !== 'user/message' && type !== 'assistant/message'
    && type !== 'tool/result') return
  const data = event['data']
  const record = typeof data === 'object' && data !== null
    ? data as Record<string, unknown>

View on GitHub (pinned to b150a551b8)

Solutions

1. Fix adapterDefaults to the valid shape in the seed request header.

When it happens

Trigger: Thrown at packages/core/session/src/index.ts:289 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/fbfadbb892a5ba27. Report an issue: GitHub.