What causes "summarization produced no text summary content" in deepseek-ai/deepseek-harness?

Route summarization to a plain instruction-following text model via summarizationProvider/summarizationModel

deepseek-ai/deepseek-harness · error · Error

summarization produced no text summary content

Error message

summarization produced no text summary content

What it means

The summarization stream finished without a finish error, but after the safe-text projection no text block with non-whitespace content remains — the model returned only reasoning or tool-call blocks, or empty text. Only returned text may enter the checkpoint, so the transaction fails rather than write an empty checkpoint (image output fails earlier with UNSUPPORTED_CONTENT).

Source

Thrown at packages/compaction/compaction-basic/src/summarizer.ts:171

  const options: GenerateOptions = {
    provider: target.provider,
    model: target.model,
    messages,
    ...input.system === undefined ? {} : { system: input.system },
    ...input.tools === undefined ? {} : { tools: [...input.tools] },
    maxTokens: config.maxTokens,
    sessionId: agent.session.id,
    purpose: 'compaction',
    ...signal === undefined ? {} : { signal },
  }
  for await (const chunk of ctx.llm.stream(options)) assembler.push(chunk)
  const error = finishError(assembler.finish)
  if (error !== undefined) throw error

  const rawOutput = assembler.blocks()
  const summary = summaryText(rawOutput)
  if (!summary.some(block => block.text.trim().length > 0)) {
    throw new Error('summarization produced no text summary content')
  }
  return {
    summary,
    rawOutput,
    llmStreamCall: true,
    provider: options.provider,
    model: options.model,
    maxTokens: config.maxTokens,
    ...(assembler.usage === undefined ? {} : { usage: assembler.usage }),
  }
}

/**
 * Wrap raw summary blocks in the durable checkpoint framing.
 * @param summary - safe text-only model output.
 * @returns content for the synthesized replacement user message.
 */
export function frameSummary(summary: readonly ContentBlock[]): ContentBlock[] {

View on GitHub (pinned to b150a551b8)

Solutions

Route summarization to a plain instruction-following text model via summarizationProvider/summarizationModel
Retry once — empty completions are often transient
Inspect the provider response for the purpose:'compaction' call to see what the model actually returned
If it persists, override the protected summarize() hook with a deterministic summarizer

Example fix

// before: summarizer routed to a tool-forward agent model
ctx.plugin(BasicCompactionEngine, {
  summarizationProvider: 'local',
  summarizationModel: 'agent-tuned-model',
})

// after: plain text model for the auxiliary call
ctx.plugin(BasicCompactionEngine, {
  summarizationProvider: 'deepseek',
  summarizationModel: 'deepseek-chat',
})

Defensive patterns

Strategy: retry

Type guard

const isEmptySummary = (error: unknown): error is Error =>
  error instanceof Error && error.message === 'summarization produced no text summary content'

Try / catch

for (let attempt = 0; ; attempt += 1) {
  try {
    return await ctx.compaction.compactNow(agent, signal)
  } catch (error) {
    if (isEmptySummary(error) && attempt < 1) continue // empty completions are often transient
    throw error
  }
}

Prevention

Route summarization to a plain instruction-following text model, not an agent-tuned one
Retry once on empty output before treating it as a configuration problem
If a model repeatedly answers the compaction instruction with tool calls or empty text, override the summarize() hook or change the summarization model

When it happens

Trigger: A tool-forward model answers the compaction instruction with a tool-call despite the 'output only the checkpoint text' rule; a reasoning model whose filtered visible output is empty; a provider returning an empty completion under load.

Common situations: Summarization routed to an agent-tuned local model; intermittent empty completions from the provider; instruction-following regressions after a model swap.

Related errors

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/abb066279d8dcace. Report an issue: GitHub.