~ LOSSY

any-llm 1.40.2

stream.missing-finish · openai-chat

Requirements

Id	Level	Status	Evidence
no-normal-stop	MUST	SATISFIED	outcome=returned; finish.value=null (absent); truth.finish="none"; forbidden finish="stop"
stream-incomplete	MUST	NOT_OBSERVABLE	stream.completed=null; outcome=returned; truth.stream_completed=false

What the provider sent

Finish: none
Raw finish: null
Text: A traditional Japanese breakfast is built around rice, soup, and a
Tool calls: []
Usage: { "alternatives": {}, "cached_input": null, "input": null, "output": null, "raw": null, "reasoning": null, "total": null }
Stream completed: false
Error: null

Wire excerpt

status: 200
content-type: text/event-stream; charset=utf-8
body (sse):
data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"role":"assistant","content":"","refusal":null},"finish_reason":null}],"usage":null,"obfuscation":""}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":"A"},"finish_reason":null}],"usage":null,"obfuscation":"b"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" traditional"},"finish_reason":null}],"usage":null,"obfuscation":"d52OTd"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" Japanese"},"finish_reason":null}],"usage":null,"obfuscation":"w1dZTLipP"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" breakfast"},"finish_reason":null}],"usage":null,"obfuscation":"MWjy8UlZ"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" is"},"finish_reason":null}],"usage":null,"obfuscation":"icVTZPFYRG5lFwL"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" built"},"finish_reason":null}],"usage":null,"obfuscation":"AYTZtVaq9EDe"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" around"},"finish_reason":null}],"usage":null,"obfuscation":"kMyBiZ4fH9u"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" rice"},"finish_reason":null}],"usage":null,"obfuscation":"ipQ7qmg7ME8qn"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":","},"finish_reason":null}],"usage":null,"obfuscation":"F"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" soup"},"finish_reason":null}],"usage":null,"obfuscation":"koHOHl6FSzjzv"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":","},"finish_reason":null}],"usage":null,"obfuscation":"c"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" and"},"finish_reason":null}],"usage":null,"obfuscation":"zgb5ipuHgdlxrv"}


data: {"id":"chatcmpl-EXmWZAYmW8gL0ntPfYzZYrbv99Dcb","object":"chat.completion.chunk","created":1791720059,"model":"gpt-6-luna","service_tier":"default","system_fingerprint":null,"choices":[{"index":0,"delta":{"content":" a"},"finish_reason":null}],"usage":null,"obfuscation":""}

What the library reported

Outcome

returned

Finish

{
  "raw": null,
  "source": null,
  "surface": "absent",
  "value": null
}

Text

Value: A traditional Japanese breakfast is built around rice, soup, and a
Surface: primary

Tool calls

[]

Usage

{
  "cached_input": null,
  "input": null,
  "output": null,
  "reasoning": null,
  "surface": {
    "cached_input": "absent",
    "input": "absent",
    "output": "absent",
    "reasoning": "absent",
    "total": "absent"
  },
  "total": null
}

Stream

{
  "chunks_seen": 14,
  "completed": null,
  "used": true
}

Error

null

Unsupported reason

null

Full observation JSON

{
  "elapsed_ms": 190.0935247540474,
  "error": null,
  "finish": {
    "raw": null,
    "source": null,
    "surface": "absent",
    "value": null
  },
  "format": "wiretruth.observation/v1",
  "library": {
    "api": "any_llm.completion",
    "language": "python",
    "name": "any-llm",
    "version": "1.40.2"
  },
  "notes": [],
  "outcome": "returned",
  "stream": {
    "chunks_seen": 14,
    "completed": null,
    "used": true
  },
  "structured": {
    "attempted": false,
    "returned_as_success": false,
    "value": null
  },
  "text": {
    "surface": "primary",
    "value": "A traditional Japanese breakfast is built around rice, soup, and a"
  },
  "tool_calls": [],
  "unsupported_reason": null,
  "usage": {
    "cached_input": null,
    "input": null,
    "output": null,
    "reasoning": null,
    "surface": {
      "cached_input": "absent",
      "input": "absent",
      "output": "absent",
      "reasoning": "absent",
      "total": "absent"
    },
    "total": null
  }
}

Fixture

derived openai-chat/stream.missing-finish

Provenance	Value
Transform	strip_finish
Source fixture	openai-chat/truncation.text-stream-usage
Rationale	The stream ends cleanly without its finish signal.
Evidence	https://github.com/pydantic/pydantic-ai/issues/6610

Reproduce

wiretruth serve openai-chat/stream.missing-finish

Plain-library snippet from the shim manifest.

any_llm.completion(model=model, provider='openai', api_base=WIRETRUTH_BASE_URL_OPENAI_CHAT, api_key=WIRETRUTH_API_KEY)

Upstream

reported Issue

Fixed in: not specified

A stream that ends before the provider's terminal signal returns the partial chunks normally, with no error and no incomplete flag (reproduced on 1.40.2 and 1.50.0). The OpenAI Responses path reports the output item as incomplete and passes.

History

Version	Grade
1.40.2	~ LOSSY
1.38.0	~ LOSSY
1.33.0	~ LOSSY