✓ PASS

pydantic-ai 2.61.0

truncation.text-stream-usage · gemini

Requirements

Id	Level	Status	Evidence
cause-is-truncation	MUST	SATISFIED	finish.value="length" (primary: ModelResponse.finish_reason); truth.finish="length"; error.category=null; structured.returned_as_success=false
text-reported	SHOULD	SATISFIED	text.value="A traditional Japanese breakfast (Asagohan) is a beautifully" (primary); truth.text="A traditional Japanese breakfast (Asagohan) is a beautifully"
usage-reported	SHOULD	SATISFIED	usage.input=36 (primary); truth.usage.input=36; usage.output=12 (primary); truth.usage.output=12

What the provider sent

Finish: length
Raw finish: MAX_TOKENS
Text: A traditional Japanese breakfast (*Asagohan*) is a beautifully
Tool calls: []
Usage: { "alternatives": {}, "cached_input": null, "input": 36, "output": 12, "raw": { "candidatesTokenCount": 12, "promptTokenCount": 36, "promptTokensDetails": [ { "modality": "TEXT", "tokenCount": 36 } ], "serviceTier": "standard", "totalTokenCount": 48 }, "reasoning": null, "total": 48 }
Stream completed: true
Error: null

Wire excerpt

status: 200
content-type: text/event-stream
body (sse):
data: {"candidates": [{"content": {"parts": [{"text": "A traditional"}],"role": "model"},"index": 0}],"usageMetadata": {"promptTokenCount": 36,"candidatesTokenCount": 2,"totalTokenCount": 38,"promptTokensDetails": [{"modality": "TEXT","tokenCount": 36}],"serviceTier": "standard"},"modelVersion": "gemini-3.5-flash-lite","responseId": "nwTOas7UFJee1MkPzOjWoQg"}


data: {"candidates": [{"content": {"parts": [{"text": " Japanese breakfast (*Asagohan*) is a beautifully"}],"role": "model"},"index": 0}],"usageMetadata": {"promptTokenCount": 36,"candidatesTokenCount": 12,"totalTokenCount": 48,"promptTokensDetails": [{"modality": "TEXT","tokenCount": 36}],"serviceTier": "standard"},"modelVersion": "gemini-3.5-flash-lite","responseId": "nwTOas7UFJee1MkPzOjWoQg"}


data: {"candidates": [{"content": {"parts": [{"text": "","thoughtSignature": "EmAKXgFpFH0TCQP7jZV7ol4IlmGfO/MLokQEa/Fvb8AEmEuaDRR/RrCQdmL+BJoMeLm3Qg10DtXxTogo4Vc0rAlnsdWd2/MKjxW2267tztLQgdhMZGvKYygnUUScYoGPAGw="}],"role": "model"},"finishReason": "MAX_TOKENS","index": 0}],"usageMetadata": {"promptTokenCount": 36,"candidatesTokenCount": 12,"totalTokenCount": 48,"promptTokensDetails": [{"modality": "TEXT","tokenCount": 36}],"serviceTier": "standard"},"modelVersion": "gemini-3.5-flash-lite","responseId": "nwTOas7UFJee1MkPzOjWoQg"}

What the library reported

Outcome

returned

Finish

{
  "raw": "MAX_TOKENS",
  "source": "ModelResponse.finish_reason",
  "surface": "primary",
  "value": "length"
}

Text

Value: A traditional Japanese breakfast (*Asagohan*) is a beautifully
Surface: primary

Tool calls

[]

Usage

{
  "cached_input": 0,
  "input": 36,
  "output": 12,
  "reasoning": 0,
  "surface": {
    "cached_input": "primary",
    "input": "primary",
    "output": "primary",
    "reasoning": "primary",
    "total": "primary"
  },
  "total": 48
}

Stream

{
  "chunks_seen": 6,
  "completed": true,
  "used": true
}

Error

null

Unsupported reason

null

Full observation JSON

{
  "elapsed_ms": 287.2346695512533,
  "error": null,
  "finish": {
    "raw": "MAX_TOKENS",
    "source": "ModelResponse.finish_reason",
    "surface": "primary",
    "value": "length"
  },
  "format": "wiretruth.observation/v1",
  "library": {
    "api": "Agent.run_stream_events",
    "language": "python",
    "name": "pydantic-ai",
    "version": "2.61.0"
  },
  "notes": [],
  "outcome": "returned",
  "stream": {
    "chunks_seen": 6,
    "completed": true,
    "used": true
  },
  "structured": {
    "attempted": false,
    "returned_as_success": false,
    "value": null
  },
  "text": {
    "surface": "primary",
    "value": "A traditional Japanese breakfast (*Asagohan*) is a beautifully"
  },
  "tool_calls": [],
  "unsupported_reason": null,
  "usage": {
    "cached_input": 0,
    "input": 36,
    "output": 12,
    "reasoning": 0,
    "surface": {
      "cached_input": "primary",
      "input": "primary",
      "output": "primary",
      "reasoning": "primary",
      "total": "primary"
    },
    "total": 48
  }
}

Fixture

recorded gemini/truncation.text-stream-usage

Provenance	Value
Recorded at	2026-10-13T10:14:55Z
Requested model	gemini-3.5-flash-lite
Returned model	gemini-3.5-flash-lite
CI run	https://github.com/kartsan03/wiretruth/actions/runs/38381941285

Reproduce

wiretruth serve gemini/truncation.text-stream-usage

Plain-library snippet from the shim manifest.

GoogleModel(model, provider=GoogleProvider(base_url=WIRETRUTH_BASE_URL_GEMINI, api_key=WIRETRUTH_API_KEY)); host root

Upstream

No matching upstream report.

History

Version	Grade
2.61.0	✓ PASS
2.56.0	✓ PASS