autourgos-openaichat

A single, self-contained LLM wrapper for the OpenAI Chat Completions API, and by extension every provider that speaks the same protocol (Groq, Gemini, Azure, Ollama, and more). Part of the Autourgos agentic-AI framework, but has zero dependency on it: pip install openai and you're ready.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")           # reads OPENAI_API_KEY
reply = llm.invoke("What is the capital of France?")
print(reply)
# Paris

---

Features

• One interface, any OpenAI-compatible provider: OpenAI, Azure, Groq, Gemini, Mistral, DeepSeek, Ollama, and more, switched with just base_url + model
• Sync and async generation, plus streaming for both, multi-turn conversations, prompt templates, and multi-modal vision input
• Structured output validated against a Pydantic model (with an automatic validation-retry loop), plain JSON mode, and native tool / function calling
• Automatic retries with exponential back-off, a circuit breaker for cascading-failure protection, and an automatic provider fallback chain — no proxy/gateway needed
• Built-in cost/latency tracking, plus a budget governor that hard-stops calls once a USD cap is reached
• Optional local call ledger (SQLite, no external service) and shadow-mode dual dispatch for comparing providers concurrently
• Optional PII/secret redaction: a heuristic pre-flight scrubber that masks (or blocks) emails, API keys, credit cards, SSNs, and phone numbers — with a bring-your-own-dictionary option and reversible restore-in-response
• extra_body= passthrough for provider-specific request fields — e.g. vLLM's guided_json/guided_regex or llama.cpp's grammar for constrained decoding
• Fully typed (py.typed), sync/async context managers, low-level raw-response access

---

Table of Contents

• Install
• Supported Providers
• Provider Examples
  • OpenAI
  • Azure OpenAI
  • Google Gemini
  • Groq
  • xAI (Grok)
  • OpenRouter
  • Together AI
  • Mistral AI
  • DeepSeek
  • Perplexity
  • Ollama
  • LM Studio
  • vLLM
  • Switching providers at runtime
• Core Usage
  • Basics
  • Text Generation
  • Async Generation
  • Streaming
  • Async Streaming
  • Batch Invocation
  • System Prompt
  • Prompt Templates
  • Multi-Turn Conversations
  • Vision Input
  • Structured & tool output
  • Structured Output
  • Validated Structured Output
  • JSON Mode
  • Native Tool Calling
  • Reliability
  • Circuit Breaker
  • Provider Fallback Chain
  • Cost
  • Cost Tracking
  • Budget Governor
  • Observability
  • Call Ledger (Audit Trail)
  • Shadow-Mode Dual Dispatch
  • Security
  • PII / Secret Redaction
  • Advanced
  • Constrained Decoding / Provider-Specific Params
  • Context Manager
  • Low-Level Access
  • Error Handling
• Constructor Reference
• API Reference
• License

---

Install

pip install autourgos-openaichat

Requires Python 3.10+ and openai>=1.0.0. Structured output (output_schema=) additionally needs pydantic>=2.0 if you use it.

---

Supported Providers

Almost every major LLM provider exposes an OpenAI-compatible API: same request format as OpenAI's Chat Completions endpoint. Point base_url at the provider and model at whatever they offer; nothing else changes.

Provider	base_url	Get a key
OpenAI	(default, omit)	https://platform.openai.com/api-keys
Azure OpenAI	https://<resource>.openai.azure.com/openai/deployments/<deployment>	Azure Portal
Google Gemini	https://generativelanguage.googleapis.com/v1beta/openai/	https://aistudio.google.com/apikey
Groq	https://api.groq.com/openai/v1	https://console.groq.com
xAI (Grok)	https://api.x.ai/v1	https://console.x.ai
OpenRouter	https://openrouter.ai/api/v1	https://openrouter.ai/keys
Together AI	https://api.together.xyz/v1	https://api.together.xyz
Mistral AI	https://api.mistral.ai/v1	https://console.mistral.ai
DeepSeek	https://api.deepseek.com/v1	https://platform.deepseek.com
Perplexity	https://api.perplexity.ai	https://www.perplexity.ai/settings/api
Ollama (local)	http://localhost:11434/v1	none, runs on your machine
LM Studio (local)	http://localhost:1234/v1	none, runs on your machine
vLLM (self-hosted)	http://your-server:8000/v1	none, you host it

---

Provider Examples

Every example below is the full, runnable snippet. Swap in your own key and go.

OpenAI

The default provider. No base_url needed.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    api_key="sk-...",           # or set OPENAI_API_KEY env var
)
reply = llm.invoke("What is the capital of France?")
print(reply)
# Paris

Azure OpenAI

Azure hosts OpenAI models in your own subscription. model is your deployment name in Azure, not the base model name. Get your endpoint and key from the Azure Portal.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",              # your deployment name in Azure
    api_key="...",               # Azure OpenAI key
    base_url="https://<your-resource>.openai.azure.com/openai/deployments/gpt-4o",
)
reply = llm.invoke("What is cloud computing?")
print(reply)
# Cloud computing is the delivery of computing services over the internet
# (servers, storage, databases, networking, software) on a pay-as-you-go basis.

Google Gemini

Gemini exposes an OpenAI-compatible endpoint, so no separate Google SDK is needed. Get your key at https://aistudio.google.com/apikey.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gemini-2.0-flash",
    api_key="...",               # Gemini API key
    base_url="https://generativelanguage.googleapis.com/v1beta/openai/",
)
reply = llm.invoke("Explain photosynthesis in one sentence.")
print(reply)
# Photosynthesis is the process by which plants convert sunlight, water, and
# carbon dioxide into glucose and oxygen.

Other Gemini models: gemini-2.0-flash-lite, gemini-1.5-pro, gemini-1.5-flash.

Groq (fastest inference, free tier available)

Groq runs open-source models (Llama 3, Mixtral, Gemma) at extremely high speed. Get your key at https://console.groq.com.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="llama3-70b-8192",
    api_key="gsk_...",           # Groq API key
    base_url="https://api.groq.com/openai/v1",
)
reply = llm.invoke("Explain quantum entanglement simply.")
print(reply)
# Quantum entanglement is when two particles become linked so that
# the state of one instantly affects the other, no matter how far apart they are.

Other Groq models: llama3-8b-8192, mixtral-8x7b-32768, gemma2-9b-it.

xAI (Grok)

Get your key at https://console.x.ai.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="grok-2-latest",
    api_key="xai-...",           # xAI API key
    base_url="https://api.x.ai/v1",
)
reply = llm.invoke("What makes Mars red?")
print(reply)
# Mars appears red because its surface is covered in iron oxide (rust),
# formed when iron in the soil reacted with trace oxygen long ago.

OpenRouter (one key, hundreds of models)

OpenRouter proxies dozens of providers (including Anthropic Claude and Google Gemini) behind a single OpenAI-compatible API and one API key. Get your key at https://openrouter.ai/keys.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="anthropic/claude-3.5-sonnet",   # or "google/gemini-2.0-flash-001", "openai/gpt-4o", ...
    api_key="sk-or-...",         # OpenRouter API key
    base_url="https://openrouter.ai/api/v1",
)
reply = llm.invoke("Write a Python one-liner to reverse a string.")
print(reply)
# s[::-1]

Together AI (wide model selection)

Together AI hosts hundreds of open-source models. Get your key at https://api.together.xyz.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="meta-llama/Llama-3-70b-chat-hf",
    api_key="...",                # Together AI key
    base_url="https://api.together.xyz/v1",
)
reply = llm.invoke("Write a Python function to reverse a string.")
print(reply)
# def reverse_string(s: str) -> str:
#     return s[::-1]

Other Together AI models: mistralai/Mixtral-8x7B-Instruct-v0.1, Qwen/Qwen2-72B-Instruct.

Mistral AI

Get your key at https://console.mistral.ai.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="mistral-large-latest",
    api_key="...",                # Mistral API key
    base_url="https://api.mistral.ai/v1",
)
reply = llm.invoke("What are the benefits of test-driven development?")
print(reply)
# TDD helps you write cleaner code, catch bugs early, and gives
# you confidence to refactor without breaking existing behaviour.

Other Mistral models: mistral-medium-latest, mistral-small-latest, open-mixtral-8x7b.

DeepSeek

Get your key at https://platform.deepseek.com.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="deepseek-chat",
    api_key="...",                # DeepSeek API key
    base_url="https://api.deepseek.com/v1",
)
reply = llm.invoke("Summarise the history of the Roman Empire in 2 sentences.")
print(reply)
# The Roman Empire rose from a small city-state to dominate the Mediterranean world
# for over 500 years. It split into Western and Eastern halves, with the West falling
# in 476 AD and the East (Byzantine Empire) surviving until 1453.

Other DeepSeek models: deepseek-reasoner.

Perplexity (web-connected models)

Perplexity's Sonar models can search the web in real time. Get your key at https://www.perplexity.ai/settings/api.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="llama-3.1-sonar-large-128k-online",
    api_key="pplx-...",           # Perplexity API key
    base_url="https://api.perplexity.ai",
)
reply = llm.invoke("What is the latest version of Python?")
print(reply)
# Python 3.13.x is the latest stable release as of 2025...

Ollama (run any model locally, no internet needed)

Ollama runs models entirely on your machine. Install from https://ollama.com, then pull a model:

ollama pull llama3

No API key needed for local use.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="llama3",
    api_key="ollama",             # can be any string, Ollama ignores it
    base_url="http://localhost:11434/v1",
)
reply = llm.invoke("What is machine learning?")
print(reply)
# Machine learning is a subset of AI where algorithms learn patterns
# from data to make predictions or decisions without explicit programming.

Other Ollama models: mistral, phi3, gemma2, codellama, qwen2, and anything you pull with ollama pull.

LM Studio (local models with a GUI)

LM Studio lets you download and run GGUF models locally. Start the local server in LM Studio, then:

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="local-model",          # use whatever model name LM Studio shows
    api_key="lm-studio",          # any string, ignored locally
    base_url="http://localhost:1234/v1",
)
reply = llm.invoke("Tell me a short joke.")
print(reply)
# Why do programmers prefer dark mode? Because light attracts bugs!

vLLM (self-hosted high-throughput serving)

vLLM lets you host your own models with high throughput. After starting your vLLM server:

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="meta-llama/Meta-Llama-3-8B-Instruct",
    api_key="EMPTY",              # vLLM's default when no auth is configured
    base_url="http://your-server:8000/v1",
)
reply = llm.invoke("What is the capital of Japan?")
print(reply)
# Tokyo

Switching providers at runtime

Because all these providers use the same interface, switching is trivial:

from autourgos_openaichat import OpenAIChatModel

PROVIDERS = {
    "openai": {
        "model": "gpt-4o-mini",
        "api_key": "sk-...",
        "base_url": None,
    },
    "groq": {
        "model": "llama3-8b-8192",
        "api_key": "gsk_...",
        "base_url": "https://api.groq.com/openai/v1",
    },
    "gemini": {
        "model": "gemini-2.0-flash",
        "api_key": "...",
        "base_url": "https://generativelanguage.googleapis.com/v1beta/openai/",
    },
}

for name, cfg in PROVIDERS.items():
    llm = OpenAIChatModel(**cfg)
    reply = llm.invoke("Say hello in one word.")
    print(f"{name}: {reply}")

# openai: Hello!
# groq:   Hello!
# gemini: Hello!

---

Core Usage

Text Generation

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    api_key="sk-...",             # or set OPENAI_API_KEY env var
    temperature=0.7,
    max_tokens=256,
)

reply = llm.invoke("Explain machine learning in one sentence.")
print(reply)
# Machine learning is a branch of AI where systems learn from data
# to make predictions or decisions without being explicitly programmed.

Async Generation

import asyncio
from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

async def main():
    reply = await llm.ainvoke("What is the speed of light?")
    print(reply)
    # The speed of light in a vacuum is approximately 299,792,458 metres per second.

asyncio.run(main())

Streaming

Stream the response token by token, synchronously.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

for chunk in llm.stream("Write a haiku about rain."):
    print(chunk, end="", flush=True)

# Raindrops softly fall,
# Washing the grey streets below,
# Earth breathes once again.

You can also enable streaming at construction time so invoke() internally streams and returns the full joined text:

llm = OpenAIChatModel(model="gpt-4o", streaming=True)
reply = llm.invoke("Tell me a fun fact.")
print(reply)
# Honey never spoils. Archaeologists have found 3,000-year-old honey in Egyptian tombs.

Async Streaming

import asyncio
from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

async def main():
    async for chunk in llm.astream("Count from 1 to 5 slowly."):
        print(chunk, end="", flush=True)
    # 1... 2... 3... 4... 5...

asyncio.run(main())

Batch Invocation

Synchronous (sequential):

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o-mini")

prompts = [
    "Capital of Japan?",
    "Capital of Germany?",
    "Capital of Brazil?",
]

results = llm.batch_invoke(prompts)
for prompt, result in zip(prompts, results):
    print(f"{prompt} -> {result}")

# Capital of Japan?   -> Tokyo
# Capital of Germany? -> Berlin
# Capital of Brazil?  -> Brasilia

Async (concurrent):

import asyncio
from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o-mini")

async def main():
    results = await llm.abatch_invoke([
        "Capital of Japan?",
        "Capital of Germany?",
        "Capital of Brazil?",
    ])
    print(results)
    # ['Tokyo', 'Berlin', 'Brasilia']

asyncio.run(main())

System Prompt

Set a persistent system prompt for all requests.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    system_prompt="You are a pirate. Always respond in pirate speak.",
)

reply = llm.invoke("What time is it?")
print(reply)
# Arrr, I know not the exact hour, but the sun be high in the sky, matey!

Prompt Templates

Define a reusable template with {placeholders} and fill them at call time.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    prompt_template="Translate the following text to {language}:\n\n{text}",
)

reply = llm.invoke(prompt_variables={"language": "French", "text": "Good morning!"})
print(reply)
# Bonjour !

reply = llm.invoke(prompt_variables={"language": "Spanish", "text": "Thank you very much."})
print(reply)
# Muchas gracias.

Missing variables raise a clear error:

llm.invoke(prompt_variables={"language": "French"})
# ValueError: Missing prompt template variables: text

Multi-Turn Conversations

Pass a list of messages directly.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

messages = [
    {"role": "user",      "content": "My name is Jitin."},
    {"role": "assistant", "content": "Nice to meet you, Jitin!"},
    {"role": "user",      "content": "What is my name?"},
]

reply = llm.invoke(messages)
print(reply)
# Your name is Jitin.

Vision Input

Pass image files, URLs, or raw bytes alongside text.

Note: vision support depends on the provider and model. GPT-4o, Gemini, LLaVA (on Ollama), and several others support it.

Warning: the file-path branch reads whatever local path it's given and base64-embeds its contents into the outgoing API request, with no path validation. Do not pass LLM- or tool-controlled paths through unchecked. An unchecked path could be used to exfiltrate arbitrary local files.

From a file path:

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")
reply = llm.invoke("What objects are in this image?", files=["photo.jpg"])
print(reply)
# The image shows a wooden desk with a laptop, a coffee mug, and a notebook.

From a URL:

reply = llm.invoke(
    "Describe this chart.",
    files=["https://example.com/chart.png"],
)
print(reply)
# The chart is a bar graph showing monthly sales figures from January to December...

From raw bytes:

with open("diagram.png", "rb") as f:
    image_bytes = f.read()

reply = llm.invoke("What does this diagram show?", files=[image_bytes])
print(reply)
# The diagram illustrates the flow of data through a neural network...

Control the detail level:

reply = llm.invoke(
    "Read the text in this image carefully.",
    files=["screenshot.png"],
    image_detail="high",   # "low", "high", or "auto"
)
print(reply)
# The screenshot shows a terminal window with the command "pip install autourgos-openaichat" ...

Structured Output

Return a Pydantic model as JSON automatically.

from pydantic import BaseModel, Field
from autourgos_openaichat import OpenAIChatModel
import json

class CityInfo(BaseModel):
    city: str = Field(description="Name of the city")
    country: str = Field(description="Name of the country")
    population: int = Field(description="Approximate population")

llm = OpenAIChatModel(model="gpt-4o", output_schema=CityInfo)
result = llm.invoke("Tell me about Tokyo.")

# result is a metadata dict; the JSON string is in result["response"]
data = json.loads(result["response"])
print(data)
# {"city": "Tokyo", "country": "Japan", "population": 13960000}

Validated Structured Output

invoke_structured() builds on output_schema= and closes the loop: instead of a raw JSON string you get back a validated Pydantic instance directly. If the response fails validation (a missing field, a failed @field_validator, a provider that ignores strict JSON-schema mode, ...), the validation error is fed back to the model as a correction message and the request is retried, up to max_validation_retries times.

from pydantic import BaseModel, Field
from autourgos_openaichat import OpenAIChatModel

class CityInfo(BaseModel):
    city: str = Field(description="Name of the city")
    country: str = Field(description="Name of the country")
    population: int = Field(description="Approximate population")

llm = OpenAIChatModel(model="gpt-4o", output_schema=CityInfo)

result = llm.invoke_structured("Tell me about Tokyo.")
print(result)
# CityInfo(city='Tokyo', country='Japan', population=13960000)
print(result.population)
# 13960000

print(llm.last_metadata["validation_retries"])
# 0  (no correction was needed)

If validation keeps failing, OpenAIChatModelValidationError (a subclass of OpenAIChatModelResponseError) is raised with .raw_text (the last invalid response) and .validation_error (the last Pydantic error):

from autourgos_openaichat import OpenAIChatModelValidationError

try:
    result = llm.invoke_structured("Tell me about Tokyo.", max_validation_retries=1)
except OpenAIChatModelValidationError as e:
    print(f"Still invalid after retries: {e.validation_error}")
    print(f"Last raw response: {e.raw_text}")

Async version: await llm.ainvoke_structured(...).

Notes:

• output_schema must be a Pydantic BaseModel class (not a plain dict, not None) — a dict schema has no .model_validate_json() to validate against.
• Incompatible with streaming=True, same as structured_output=True.
• Each validation retry re-runs the full transport-level retry budget (max_retries) too, so worst-case cost/latency is roughly max_validation_retries × max_retries — keep max_validation_retries small (the default is 2).
• Composes with Provider Fallback Chain — each attempt goes through the same primary → fallback sequence.

JSON Mode

Force the model to return valid JSON without a schema.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    response_mime_type="application/json",
    system_prompt="Always respond with valid JSON.",
)

reply = llm.invoke("Give me a person with name and age.")
print(reply)
# {"name": "Alice", "age": 30}

Native Tool Calling

Let the model decide when to call your functions.

Tool calling support varies by provider. OpenAI, Groq, Gemini, Together AI, Mistral, and DeepSeek all support it. Ollama supports it on compatible models.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

tools = [
    {
        "name": "get_weather",
        "description": "Get the current weather for a city.",
        "parameters": {
            "type": "object",
            "properties": {
                "city": {
                    "type": "string",
                    "description": "The city name, e.g. Paris",
                },
                "unit": {
                    "type": "string",
                    "enum": ["celsius", "fahrenheit"],
                    "description": "Temperature unit",
                },
            },
            "required": ["city"],
        },
    }
]

response = llm.invoke_with_tools("What is the weather in Tokyo right now?", tools)

if response.has_tool_calls:
    for call in response.tool_calls:
        print(f"Tool: {call.name}")
        print(f"Args: {call.arguments}")
        print(f"ID:   {call.call_id}")
    # Tool: get_weather
    # Args: {'city': 'Tokyo', 'unit': 'celsius'}
    # ID:   call_abc123

elif response.is_final_answer:
    print(response.text)

Async tool calling:

response = await llm.ainvoke_with_tools(
    "What is the weather in London?", tools
)

If the model's tool-call arguments come back as malformed JSON, call.arguments falls back to {} and call.arguments_parse_error is set to a description of what went wrong — check it if a tool call ever seems to be missing arguments it should have had:

for call in response.tool_calls:
    if call.arguments_parse_error:
        print(f"Warning: {call.name}'s arguments failed to parse: {call.arguments_parse_error}")

Full agentic loop example:

import json

def get_weather(city: str, unit: str = "celsius") -> str:
    # Replace with real API call
    return json.dumps({"city": city, "temp": 22, "unit": unit, "condition": "Sunny"})

tool_functions = {"get_weather": get_weather}

messages = [{"role": "user", "content": "What is the weather in Paris?"}]

while True:
    response = llm.invoke_with_tools(messages, tools)

    if response.is_final_answer:
        print("Final answer:", response.text)
        break

    # Execute each tool call
    messages.append({
        "role": "assistant",
        "tool_calls": [
            {
                "id": tc.call_id,
                "type": "function",
                "function": {"name": tc.name, "arguments": json.dumps(tc.arguments)},
            }
            for tc in response.tool_calls
        ],
    })

    for tc in response.tool_calls:
        result = tool_functions[tc.name](**tc.arguments)
        messages.append({
            "role": "tool",
            "tool_call_id": tc.call_id,
            "content": result,
        })

# Final answer: The current weather in Paris is 22°C and Sunny.

Circuit Breaker

Protects against cascading failures. After circuit_failure_threshold consecutive API errors, all calls are blocked for circuit_cooldown_time seconds.

This is useful when you are using a local model (Ollama, LM Studio) or a rate-limited API. If the server goes down, the circuit breaker stops your code from hammering it with failed requests.

from autourgos_openaichat import OpenAIChatModel, CircuitBreakerOpenException

llm = OpenAIChatModel(
    model="gpt-4o",
    circuit_failure_threshold=3,   # open after 3 consecutive failures
    circuit_cooldown_time=60.0,    # block for 60 seconds
)

try:
    reply = llm.invoke("Hello!")
except CircuitBreakerOpenException as e:
    print(f"Circuit is open: {e}")
    # Circuit breaker OPEN for OpenAIChatModel: 3 consecutive failures.
    # Blocked until 1718500000.0.

The circuit automatically resets after the cooldown and allows one probe call through.

Provider Fallback Chain

Configure backup providers that invoke(), ainvoke(), stream(), astream(), invoke_with_tools(), and ainvoke_with_tools() transparently switch to if the primary provider fails (after its own retries are exhausted) — no proxy or gateway service needed.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    api_key="sk-...",                       # primary: OpenAI
    fallback_providers=[
        {
            "model": "llama3-70b-8192",     # 1st backup: Groq
            "api_key": "gsk_...",
            "base_url": "https://api.groq.com/openai/v1",
        },
        {
            "model": "llama3",              # 2nd backup: local Ollama
            "api_key": "ollama",
            "base_url": "http://localhost:11434/v1",
        },
    ],
)

reply = llm.invoke("What is the capital of France?")
print(reply)
# Paris (served by whichever provider succeeded first)

print(llm.last_metadata["provider_used"])
# "primary"  or  "fallback[0]:llama3-70b-8192"  or  "fallback[1]:llama3"

Each fallback entry resolves its own api_key/base_url (falling back to OPENAI_API_KEY/OPENAI_BASE_URL env vars, exactly like the primary) — nothing is inherited from the primary provider's credentials, so a backup on a different host never sees the primary's key.

If every provider fails, OpenAIChatModelAllProvidersFailedError (a subclass of OpenAIChatModelAPIError) is raised with an .attempts list of (label, exception) pairs, one per provider tried:

from autourgos_openaichat import OpenAIChatModelAllProvidersFailedError

try:
    llm.invoke("Hello!")
except OpenAIChatModelAllProvidersFailedError as e:
    for label, exc in e.attempts:
        print(f"{label}: {exc}")
    # primary: [primary] Chat Completions request failed after 3 attempts. ...
    # fallback[0]:llama3-70b-8192: [fallback[0]:llama3-70b-8192] Chat Completions request failed ...

Streaming limitation: fallback only kicks in if a provider fails before it has streamed any text. Once partial output has already reached the caller, switching providers mid-stream would duplicate or corrupt the output, so the error is raised as-is instead of silently trying the next provider.

create()/acreate() (low-level raw access) are unaffected by fallback_providers — they always call the primary client only, since their contract is "the raw response of the client you configured."

Cost Tracking

Pass pricing (USD per 1 million tokens) to get cost breakdowns.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    input_pricing=2.50,    # $2.50 per 1M input tokens
    output_pricing=10.00,  # $10.00 per 1M output tokens
    structured_output=True,
)

result = llm.invoke("Summarise the history of the internet in 3 sentences.")
print(result["model"])          # gpt-4o
print(result["response"])       # The internet began as ARPANET...
print(result["input_tokens"])   # 18
print(result["output_tokens"])  # 74
print(result["total_tokens"])   # 92
print(result["input_cost"])     # 0.000045
print(result["output_cost"])    # 0.00074
print(result["total_cost"])     # 0.000785
print(result["latency_ms"])     # 1243.5

Access the last metadata without structured_output=True:

llm = OpenAIChatModel(model="gpt-4o", input_pricing=2.50, output_pricing=10.00)
reply = llm.invoke("Hello!")
print(llm.last_metadata)
# {
#   "model": "gpt-4o",
#   "response": "Hello! How can I help you today?",
#   "input_tokens": 9,
#   "output_tokens": 10,
#   "total_tokens": 19,
#   "input_cost": 0.0000225,
#   "output_cost": 0.0001,
#   "total_cost": 0.0001225,
#   "latency_ms": 834.2
# }

Budget Governor

Set max_session_cost= (USD) to hard-stop invoke()/ainvoke()/invoke_structured()/ainvoke_structured() once accumulated session cost reaches the cap — the blocked call is rejected before it reaches the API, so no further spend happens. Requires both input_pricing and output_pricing (cost can't be computed, and the cap can't trigger, without them).

from autourgos_openaichat import OpenAIChatModel, BudgetExceededException

llm = OpenAIChatModel(
    model="gpt-4o",
    input_pricing=2.50,
    output_pricing=10.00,
    max_session_cost=0.50,   # hard stop at $0.50 for this client's lifetime
)

try:
    for prompt in many_prompts:
        reply = llm.invoke(prompt)
except BudgetExceededException as e:
    print(f"Stopped: {e}")
    print(f"Used ${llm.session_cost_used:.4f} of ${llm.max_session_cost:.4f}")

Call llm.reset_session_budget() to zero out session_cost_used and unblock a tripped cap (e.g. starting a new billing period without recreating the client).

Notes:

• This is a backstop, not an exact per-call prediction. A call's cost is only known after its response comes back, so the cap is checked against cost already accumulated from prior calls — the call that pushes you over the cap still completes; only the next one is blocked.
• Hitting the cap does not count toward the circuit breaker's failure threshold — a budget stop is not a provider failure.
• invoke_structured()/ainvoke_structured() check the budget once before the first attempt; a failed-validation retry attempt inside that call still costs money but its cost isn't tracked into session_cost_used today (only the final successful attempt's cost is recorded).
• invoke_with_tools()/ainvoke_with_tools()/stream()/astream() are not budget-protected in this version — same gap as the Call Ledger, since no usage/cost metadata is computed on those paths.

Call Ledger (Audit Trail)

Set ledger_path= to record every invoke(), ainvoke(), invoke_structured(), and ainvoke_structured() call to a local SQLite file — model, provider used, prompt/response, tokens, cost, latency, validation retries. No external service, no extra dependency (sqlite3 is part of the Python standard library). Disabled by default (ledger_path=None) — zero overhead unless you turn it on.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",
    input_pricing=2.50,
    output_pricing=10.00,
    ledger_path="calls.db",   # created if it doesn't exist
)

llm.invoke("What is the capital of France?")
llm.invoke("What is the capital of Japan?")

Query it with any SQLite tool:

sqlite3 calls.db "SELECT created_at, model, provider_used, total_cost, latency_ms FROM calls ORDER BY id;"

import sqlite3
conn = sqlite3.connect("calls.db")
for row in conn.execute("SELECT prompt, response, total_tokens FROM calls"):
    print(row)

Set ledger_store_content=False to log only tokens/cost/latency/provider metadata — no prompt/response text — if you don't want request content persisted to disk:

llm = OpenAIChatModel(model="gpt-4o", ledger_path="calls.db", ledger_store_content=False)

Notes:

• A ledger write happens synchronously on every logged call (one INSERT + commit) — fine for audit/dev/debugging, but adds I/O latency in a tight high-throughput loop. It's not meant for a hot production path.
• A ledger write can never break your actual LLM call: any failure (disk full, permissions, a closed connection) is logged as a warning and swallowed.
• invoke_with_tools()/ainvoke_with_tools()/stream()/astream() are not logged in this version — they don't compute usage/cost metadata today.
• The ledger connection is closed automatically by the context manager (with OpenAIChatModel(...) as llm:).

Shadow-Mode Dual Dispatch

Dispatch the same prompt to one or more "shadow" providers concurrently with the primary, purely for observation — invoke()/ainvoke() always return the primary's answer. Useful for catching regressions before switching a default model/provider, or for ongoing quality/cost comparison.

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="gpt-4o",                          # primary — this is what invoke() returns
    shadow_providers=[
        {"model": "gpt-4o-mini"},             # compare against a cheaper model
        {
            "model": "llama3-70b-8192",       # and a different provider entirely
            "api_key": "gsk_...",
            "base_url": "https://api.groq.com/openai/v1",
        },
    ],
)

reply = llm.invoke("What is the capital of France?")
print(reply)
# Paris   (always from the primary — gpt-4o)

for shadow in llm.last_shadow_results:
    print(shadow)
# {'provider_used': 'shadow[0]:gpt-4o-mini', 'response': 'Paris', 'similarity': 1.0,
#  'input_tokens': 8, 'output_tokens': 1, 'total_cost': None, 'latency_ms': 210.4, 'error': None}
# {'provider_used': 'shadow[1]:llama3-70b-8192', 'response': 'The capital of France is Paris.',
#  'similarity': 0.42, 'input_tokens': 8, 'output_tokens': 7, 'total_cost': None,
#  'latency_ms': 340.1, 'error': None}

similarity is a 0.0-1.0 text-overlap ratio (stdlib difflib) against the primary's response — a rough signal, not semantic similarity. React to results live with on_shadow_result=:

def alert_on_drift(shadow_result):
    if shadow_result["similarity"] is not None and shadow_result["similarity"] < 0.5:
        print(f"Drift detected from {shadow_result['provider_used']}!")

llm = OpenAIChatModel(model="gpt-4o", shadow_providers=[...], on_shadow_result=alert_on_drift)

Notes:

• Adds latency: primary and shadow providers run concurrently (ThreadPoolExecutor for invoke(), asyncio.gather for ainvoke()), so total call time is roughly max(primary_latency, slowest_shadow_latency) — not the sum, but not zero overhead either. invoke() waits for every shadow provider to finish (or fail) before returning.
• Costs real money: each shadow provider gets one live API call per invocation. This cost is tracked in each shadow result's total_cost but is not added to session_cost_used / counted against max_session_cost.
• Each shadow provider gets a single attempt — no retries. A shadow failure never raises and never affects the primary's result; it just shows up with error set in last_shadow_results.
• Only invoke()/ainvoke() dispatch shadows in this version — stream()/astream()/invoke_with_tools()/invoke_structured() don't.
• If Call Ledger is enabled, every shadow result is also recorded in a separate shadow_calls table.

PII / Secret Redaction

This is a heuristic, best-effort scrubber, not a compliance-grade DLP solution. It's regex-based: it will miss PII that doesn't match a known pattern (false negatives — a name, a home address, an unusual key format), and it will occasionally mask legitimate content that happens to match a pattern (false positives — e.g. a user asking "what does a US SSN look like, 123-45-6789?"). Use it as one layer of defense-in-depth, not a guarantee. Disabled by default.

Set redact_pii=True to scan the resolved prompt (string or a pre-built messages list) for likely secrets/PII before it's sent to the provider — covers every call path (invoke, ainvoke, stream, astream, invoke_with_tools, ainvoke_with_tools, invoke_structured, ainvoke_structured), since they all resolve the prompt through the same code path. Built-in categories: email, credit_card, ssn, phone, api_key (OpenAI sk-, GitHub ghp_/github_pat_, AWS AKIA, Google AIza, Slack xox*-, JWTs).

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o", redact_pii=True)

reply = llm.invoke("My email is bob@example.com and my key is sk-abc123...")
# The model actually receives:
# "My email is [REDACTED:email] and my key is [REDACTED:api_key]"

print(llm.last_redacted_categories)
# ["email", "api_key"]

Restrict to specific categories, or add your own patterns:

llm = OpenAIChatModel(
    model="gpt-4o",
    redact_pii=True,
    redact_categories=["email", "api_key"],           # skip credit_card/ssn/phone
    redact_custom_patterns={"internal_id": r"EMP-\d{5}"},
)

Bring your own redaction dictionary

The 5 built-in categories are intentionally generic. For a domain with its own sensitive vocabulary — codenames, asset IDs, classification markings, unit designations — bring your own dictionary instead of writing regex for everything:

llm = OpenAIChatModel(
    model="gpt-4o",
    redact_pii=True,
    redact_categories=[],   # turn off all 5 built-ins — use only your own dictionary
    redact_custom_terms={
        "codenames": ["EAGLE STRIKE", "MIDNIGHT RAVEN"],   # exact literal values, no regex needed
        "units": ["3rd Battalion", "7th Brigade"],
    },
    redact_custom_patterns={
        "classification_marking": r"(TOP SECRET|SECRET|CONFIDENTIAL)(//[A-Z/]+)?",
    },
    redact_mode="block",   # masking a classification banner doesn't protect what's under it
)

redact_custom_terms values are matched literally (each one is regex-escaped for you) — use it for a fixed list of known-sensitive strings. redact_custom_patterns is for when you actually need a regex.

For a team-maintained dictionary that shouldn't live in code, point redact_patterns_file at a JSON file instead:

{
  "patterns": {
    "classification_marking": "(TOP SECRET|SECRET|CONFIDENTIAL)(//[A-Z/]+)?"
  },
  "terms": {
    "codenames": ["EAGLE STRIKE", "MIDNIGHT RAVEN"],
    "units": ["3rd Battalion", "7th Brigade"]
  }
}

llm = OpenAIChatModel(
    model="gpt-4o",
    redact_pii=True,
    redact_categories=[],
    redact_patterns_file="agency_dictionary.json",
)

The file is loaded once at construction time — update it and recreate the client to pick up changes. If both a file and inline redact_custom_patterns/redact_custom_terms are given, they're merged and the inline ones win on a name collision.

Use redact_mode="block" to reject the call outright instead of masking and proceeding:

from autourgos_openaichat import OpenAIChatModelRedactionBlockedError

llm = OpenAIChatModel(model="gpt-4o", redact_pii=True, redact_mode="block")

try:
    llm.invoke("My email is bob@example.com")
except OpenAIChatModelRedactionBlockedError as e:
    print(f"Blocked, matched: {e.categories_found}")
    # Blocked, matched: ['email']

Notes:

• Only the resolved prompt (what you pass to invoke(), or the rendered prompt_template) is scanned — system_prompt (developer-authored) and vision files= content (covered by its own existing warning) are not touched.
• If Call Ledger is enabled, the ledger's prompt column reflects the already-redacted text (the raw text is never persisted), and a new redacted_categories column records which categories matched each call.

Getting the real value back: redact_restore_in_response

Masking alone means the model can only ever echo back [REDACTED:email] — never the real value. If your task doesn't need the model to reason about the secret, just not leak it, set redact_restore_in_response=True: the model still never sees the real value, but if it echoes the placeholder back, the final result you get has the original value swapped back in.

llm = OpenAIChatModel(
    model="gpt-4o",
    redact_pii=True,
    redact_categories=["email"],
    redact_restore_in_response=True,   # requires redact_pii=True and redact_mode="mask" (the default)
)

reply = llm.invoke("Summarize this ticket: user bob@example.com reported a login bug")
print(reply)
# "The user bob@example.com reported a login bug." — the real email is back

# What the model actually received:
# "Summarize this ticket: user [REDACTED:email:1] reported a login bug"

This only works when the task is a pass-through/reference, not a computation on the secret's actual value — the model never saw bob@example.com, so it can't do anything that requires knowing what it actually is (e.g. "what's the domain part of this email?" would just get the placeholder back, unresolved, since there's nothing to restore in a domain the model made up from a token it never saw).

Notes:

• Works with invoke()/ainvoke()/invoke_structured()/ainvoke_structured(). invoke_structured() restores before validating against output_schema — useful when a schema field expects a realistic value (e.g. a custom email-format validator) that a raw placeholder would fail.
• On a failed invoke_structured() validation retry, the correction message sent back to the model always uses the still-masked text, never the restored one — the real secret is never fed into the model's own conversation history, even indirectly.
• The Call Ledger always records the masked text, regardless of this setting — restoration only affects what's returned to your code, never what's persisted.
• Placeholders become unique per occurrence ([REDACTED:email:1], [REDACTED:email:2], ...) only when this is enabled, so each one restores to the correct original value; with it off, placeholders stay [REDACTED:email] as shown above.

Constrained Decoding / Provider-Specific Params

Self-hosted OpenAI-compatible servers (vLLM, llama.cpp, and others) support extra, non-standard request fields for constrained/guided generation — forcing output to match a JSON schema, a regex, a fixed set of choices, or a formal grammar. These aren't part of the OpenAI API, so the openai SDK exposes them via extra_body=. Set extra_body= on the constructor to merge your own fields into every request this client makes (primary, fallback, and shadow providers alike).

vLLM — force output to match a JSON schema (guided_json):

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(
    model="meta-llama/Meta-Llama-3-8B-Instruct",
    base_url="http://localhost:8000/v1",   # vLLM's OpenAI-compatible server
    api_key="EMPTY",
    extra_body={
        "guided_json": {
            "type": "object",
            "properties": {"name": {"type": "string"}, "age": {"type": "integer"}},
            "required": ["name", "age"],
        }
    },
)
reply = llm.invoke("Give me a fictional person's name and age.")

vLLM also supports guided_regex and guided_choice the same way. llama.cpp server — constrain with a GBNF grammar:

llm = OpenAIChatModel(
    model="local-model",
    base_url="http://localhost:8080/v1",
    api_key="not-needed",
    extra_body={"grammar": 'root ::= "yes" | "no"'},
)

Notes:

• Not validated or interpreted by this library — whatever dict you pass is sent as-is. This library doesn't know or care what the keys mean.
• Not portable: these fields are provider-specific. A provider that doesn't recognize a key will typically ignore it or reject the request — check your provider's docs. Mixing an extra_body-dependent client with fallback providers on a different backend can silently break the guided behavior on the fallback (the same extra_body is sent to all of them).
• This is a single, constructor-level setting — no per-call override in this version. It composes automatically with the Provider Fallback Chain and Shadow-Mode Dual Dispatch, since every target reuses the same base request params.
• output_schema= (this library's own structured-output feature) and extra_body={"guided_json": ...} solve a similar problem differently: output_schema uses the standard OpenAI response_format (works on OpenAI, Azure, and any provider that implements strict JSON-schema mode), while guided_json is vLLM's own mechanism for providers that don't. Use whichever your provider actually supports — you generally don't need both at once.

Context Manager

Automatically closes the HTTP client when done.

from autourgos_openaichat import OpenAIChatModel

with OpenAIChatModel(model="gpt-4o") as llm:
    reply = llm.invoke("Ping!")
    print(reply)
    # Pong! How can I help you?
# Client is closed here automatically

Async context manager:

import asyncio
from autourgos_openaichat import OpenAIChatModel

async def main():
    async with OpenAIChatModel(model="gpt-4o") as llm:
        reply = await llm.ainvoke("Hello async!")
        print(reply)

asyncio.run(main())

Low-Level Access

If you need direct access to the raw OpenAI response object:

from autourgos_openaichat import OpenAIChatModel

llm = OpenAIChatModel(model="gpt-4o")

messages = [{"role": "user", "content": "Hi"}]
raw_response = llm.create(messages)

print(raw_response.id)
print(raw_response.choices[0].message.content)
print(raw_response.usage.total_tokens)

Async:

raw_response = await llm.acreate(messages)

Error Handling

from autourgos_openaichat import (
    OpenAIChatModel,
    OpenAIChatModelAPIError,
    OpenAIChatModelAllProvidersFailedError,
    OpenAIChatModelResponseError,
    OpenAIChatModelConfigError,
    OpenAIChatModelImportError,
    CircuitBreakerOpenException,
    BudgetExceededException,
    OpenAIChatModelRedactionBlockedError,
)

llm = OpenAIChatModel(model="gpt-4o")

try:
    reply = llm.invoke("Hello!")
except OpenAIChatModelRedactionBlockedError as e:
    # redact_mode="block" and the prompt matched a redaction category
    print(f"Blocked: {e.categories_found}")
except BudgetExceededException as e:
    # max_session_cost has been reached — call was blocked before hitting the API
    print(f"Budget exceeded: {e}")
except OpenAIChatModelAllProvidersFailedError as e:
    # Primary AND every configured fallback provider failed
    print(f"All providers failed: {e.attempts}")
except OpenAIChatModelAPIError as e:
    # API request failed after all retries
    print(f"API error: {e}")
except OpenAIChatModelResponseError as e:
    # Response was received but text could not be extracted
    print(f"Response parse error: {e}")
except OpenAIChatModelConfigError as e:
    # Incompatible options (e.g. streaming + structured_output)
    print(f"Config error: {e}")
except OpenAIChatModelImportError as e:
    # openai SDK not installed
    print(f"Import error: {e}")
except CircuitBreakerOpenException as e:
    # Too many recent failures, circuit is open
    print(f"Circuit open: {e}")

Retry behaviour: by default the wrapper retries up to 3 times with exponential back-off.

Attempt	Wait before retry
1st failure	0.5 s
2nd failure	1.0 s
3rd failure	2.0 s
4th failure	raises OpenAIChatModelAPIError

Change with max_retries and backoff_factor:

llm = OpenAIChatModel(
    model="gpt-4o",
    max_retries=5,
    backoff_factor=1.0,   # waits: 1s, 2s, 4s, 8s then raises
)

---

Constructor Reference

Parameter	Type	Default	Description
model	str	required	Model name. e.g. "gpt-4o", "llama3-70b-8192", "gemini-2.0-flash", "mistral-large-latest"
api_key	str	OPENAI_API_KEY env	API key for the provider you are using
base_url	str	OPENAI_BASE_URL env	Provider endpoint. e.g. "https://api.groq.com/openai/v1" or "http://localhost:11434/v1"
organization	str	None	OpenAI organization ID (OpenAI only)
project	str	None	OpenAI project ID (OpenAI only)
system_prompt	str	None	System prompt prepended to every request
prompt_template	str	None	Template with {variable} placeholders
temperature	float	None	Sampling temperature 0 to 2. Higher = more random
top_p	float	None	Nucleus sampling 0 to 1
max_tokens	int	None	Maximum tokens to generate
output_schema	BaseModel / dict	None	Pydantic model or JSON schema for structured output
response_mime_type	str	None	"application/json" enables JSON object mode
structured_output	bool	False	If True, invoke() returns a metadata dict
streaming	bool	False	If True, invoke() streams internally and joins
max_retries	int	3	Retry attempts on transient API errors
timeout	float	60.0	Request timeout in seconds
backoff_factor	float	0.5	Exponential back-off base (wait = factor × 2^attempt)
input_pricing	float	None	USD per 1 million input tokens
output_pricing	float	None	USD per 1 million output tokens
circuit_failure_threshold	int	5	Consecutive failures before the circuit opens
circuit_cooldown_time	float	30.0	Seconds the circuit stays open before probing
fallback_providers	list[dict]	None	Ordered backup providers, each {"model", "api_key"?, "base_url"?, "organization"?, "project"?}, tried after the primary exhausts its retries
ledger_path	str	None	If set, path to a local SQLite file that records every logged call (see Call Ledger)
ledger_store_content	bool	True	If False, the ledger omits prompt/response text and logs only metadata
max_session_cost	float	None	USD hard cap — blocks further calls once session_cost_used reaches it. Requires input_pricing/output_pricing
redact_pii	bool	False	Scan the resolved prompt for likely secrets/PII before sending (see PII / Secret Redaction)
redact_categories	list[str]	None	Which built-in categories to scan (email/credit_card/ssn/phone/api_key); default = all
redact_mode	str	"mask"	"mask" replaces matches and proceeds; "block" raises instead of sending
redact_custom_patterns	dict[str, str]	None	Extra {name: regex} entries merged in alongside the built-ins
redact_custom_terms	dict[str, list[str]]	None	Exact literal values to redact, {category: [values]} — no regex needed
redact_patterns_file	str	None	Path to a JSON file with "patterns"/"terms" keys — a team-maintained dictionary outside code
redact_restore_in_response	bool	False	Swap echoed placeholders back for their original values in the returned text/ledger-excluded response. Requires redact_pii=True and redact_mode="mask"
shadow_providers	list[dict]	None	Backup providers dispatched concurrently for observation only (see Shadow-Mode Dual Dispatch)
on_shadow_result	Callable[[dict], None]	None	Callback invoked with each shadow result dict as it completes
extra_body	dict	None	Raw provider-specific request fields merged into every request (see Constrained Decoding)

---

API Reference

What Each Method Returns

Method	Returns
invoke(prompt, **overrides)	str, generated text (or dict if structured_output=True). **overrides (e.g. temperature=, top_p=, max_tokens=, stop=) apply to this call only, across the fallback chain; "messages"/"model"/"stream" can't be overridden this way
ainvoke(prompt, **overrides)	same as invoke, async
stream(prompt, **overrides)	Iterator[str], text chunks. Same per-call **overrides as invoke
astream(prompt, **overrides)	AsyncIterator[str], text chunks. Same per-call **overrides as invoke
batch_invoke(prompts)	list[str], one result per prompt
abatch_invoke(prompts)	list[str], concurrent results
invoke_with_tools(prompt, tools)	ToolCallResponse, .tool_calls list or .text
ainvoke_with_tools(prompt, tools)	same as invoke_with_tools, async
invoke_structured(prompt)	Validated instance of output_schema (raises OpenAIChatModelValidationError on exhaustion)
ainvoke_structured(prompt)	same as invoke_structured, async
create(messages)	Raw OpenAI ChatCompletion response object
acreate(messages)	same as create, async

ToolCallResponse fields

Field	Type	Description
.tool_calls	list[FunctionCall]	Tool calls the model wants to make (empty if final answer)
.text	str | None	Final text answer (None if tool calls present)
.raw	Any	Raw provider response object
.has_tool_calls	bool	True when tool_calls is non-empty
.is_final_answer	bool	True when text is present and tool_calls is empty

FunctionCall fields

Field	Type	Description
.name	str	Tool function name
.arguments	dict	Parsed JSON arguments ({} if parsing failed — see .arguments_parse_error)
.call_id	str | None	Call ID for multi-turn tracking
.arguments_parse_error	str | None	Set to the parse error message when the model's JSON arguments failed to parse; None on success

Metadata dict (when structured_output=True, or via llm.last_metadata)

Key	Type	Description
"model"	str	Model name used
"response"	str	Generated text
"input_tokens"	int | None	Input token count
"output_tokens"	int | None	Output token count
"total_tokens"	int | None	Total token count
"input_cost"	float	Input cost in USD (only if input_pricing set)
"output_cost"	float	Output cost in USD (only if output_pricing set)
"total_cost"	float	Total cost in USD (only if both pricing set)
"latency_ms"	float	Request round-trip time in milliseconds
"provider_used"	str	"primary" or "fallback[N]:<model>" — which provider actually served the request
"validation_retries"	int	Only set after invoke_structured()/ainvoke_structured() — number of correction attempts needed (0 = valid on first try)

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License

Apache License 2.0, Copyright (c) 2026 Jitin Kumar Sengar