guidellm.backends
Backend infrastructure for GuideLLM language model interactions.
Provides abstract base classes, concrete backend implementations, and response handlers for standardized communication with generative AI model providers. The backend system supports distributed execution across worker processes with pluggable response handlers for different API formats. Key components include the abstract Backend base class, OpenAI-compatible HTTP backend, and response handlers for processing streaming and non-streaming API responses.
AudioRequestHandler
Bases: ChatCompletionsRequestHandler
Request handler for audio transcription and translation endpoints.
Processes responses from audio processing APIs that convert speech to text, handling both transcription and translation services. Manages audio-specific usage metrics including audio tokens and processing duration.
Example: :: handler = AudioResponseHandler() response = handler.compile_non_streaming(request, api_response)
Source code in src/guidellm/backends/openai/request_handlers.py
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__init__()
Initialize the audio response handler.
Sets up internal state for accumulating streaming response data including audio buffers, text chunks, and usage metrics.
Source code in src/guidellm/backends/openai/request_handlers.py
compile_non_streaming(request, arguments, response)
Process a complete audio transcription or translation response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
arguments | GenerationRequestArguments | The request arguments that were sent | required |
response | dict | Complete API response containing top-level text and usage | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with extracted text and metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
extract_metrics(usage, text)
Extract input and output usage metrics from audio API response usage data.
Handles audio-specific metrics including processing duration and audio tokens in addition to standard text token counts.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
usage | dict[str, int | dict[str, int]] | None | Usage data dictionary from audio API response | required |
text | str | None | Generated text for calculating word and character counts. None means text is not applicable (metrics will be None); empty string means text was applicable but empty (metrics will be 0). | required |
Returns:
| Type | Description |
|---|---|
tuple[UsageMetrics, UsageMetrics] | Tuple of input_metrics and output_metrics as UsageMetrics objects |
Source code in src/guidellm/backends/openai/request_handlers.py
format(data, history=None, **kwargs)
Format the audio transcription generation request into the appropriate structure.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
data | GenerationRequest | The generation request to format | required |
**kwargs | Additional keyword arguments for request formatting | {} |
Returns:
| Type | Description |
|---|---|
GenerationRequestArguments | The formatted request arguments |
Source code in src/guidellm/backends/openai/request_handlers.py
post_validation(response)
Reject audio responses that omit the transcription text field.
An empty string is a valid transcription for silent or VAD-filtered audio.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
response | GenerationResponse | The compiled audio response to validate. | required |
Raises:
| Type | Description |
|---|---|
ValueError | If the response has no transcription text field. |
Source code in src/guidellm/backends/openai/request_handlers.py
Backend
Bases: RegistryMixin['type[Backend]'], BackendInterface[GenerationRequest, GenerationResponse]
Base class for generative AI backends with registry and lifecycle management.
Provides a standard interface for backends that communicate with generative AI models. Combines the registry pattern for automatic discovery with a defined lifecycle for process-based distributed execution. Backend state must be pickleable for distributed execution across process boundaries.
Backend lifecycle phases: 1. Creation and configuration 2. Process startup - Initialize resources in worker process 3. Validation - Verify backend readiness 4. Request resolution - Process generation requests 5. Process shutdown - Clean up resources
Example: :: @Backend.register("my_backend") class MyBackend(Backend): def init(self, args: MyBackendArgs): super().init(args) self.api_key = args.api_key
async def process_startup(self):
self.client = MyAPIClient(self.api_key)
args = MyBackendArgs(api_key="secret")
backend = Backend.create(args)
Source code in src/guidellm/backends/backend.py
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info property
Return a snapshot of backend configuration for logging or debugging.
processes_limit property
Returns:
| Type | Description |
|---|---|
int | None | Maximum number of worker processes supported, None if unlimited |
requests_limit property
Returns:
| Type | Description |
|---|---|
int | None | Maximum number of concurrent requests supported globally, None if unlimited |
__init__(args)
Initialize a backend instance.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
args | BackendArgs | The backend arguments object | required |
create(args) classmethod
Create a backend instance based on the backend type.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
type_ | The type of backend to create | required | |
kwargs | Additional arguments for backend initialization | required |
Returns:
| Type | Description |
|---|---|
Backend | An instance of a subclass of Backend |
Raises:
| Type | Description |
|---|---|
ValueError | If the backend type is not registered |
Source code in src/guidellm/backends/backend.py
default_model() abstractmethod async
BackendArgs
Bases: PydanticClassRegistryMixin['BackendArgs'], ABC
Base class for backend creation arguments.
This class serves as a base for defining argument models used in the creation of backend instances. It inherits from PydanticClassRegistryMixin to enable automatic registration of subclasses, allowing for flexible and extensible backend configurations.
Attributes:
| Name | Type | Description |
|---|---|---|
schema_discriminator | str | Field name for polymorphic deserialization |
Source code in src/guidellm/backends/backend.py
__pydantic_schema_base_type__() classmethod
Return base type for polymorphic validation hierarchy.
Returns:
| Type | Description |
|---|---|
type[BackendArgs] | Base BackendArgs class for schema validation |
Source code in src/guidellm/backends/backend.py
ChatCompletionsRequestHandler
Bases: TextCompletionsRequestHandler
Request handler for OpenAI-style chat completion endpoints.
Extends TextCompletionsResponseHandler to handle chat completion requests where generated text is nested within message objects in the choices array. Processes both streaming and non-streaming chat completion responses, including tool call responses where the model outputs tool_calls instead of text content.
Source code in src/guidellm/backends/openai/request_handlers.py
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last_iteration_had_content property
Returns:
| Type | Description |
|---|---|
bool | True if the last chunk carried output (text/tool-call) tokens, not solely reasoning tokens. |
add_streaming_line(line)
Process a single line from a chat completion streaming response.
Handles the chat completion specific delta structure where content is nested within delta objects in the streaming response chunks. Also accumulates tool_calls deltas when the model streams function call output.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
line | str | Raw SSE line from the streaming response | required |
Returns:
| Type | Description |
|---|---|
int | None | 1 if content was extracted, 0 if line ignored, None if done |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_non_streaming(request, arguments, response)
Process a complete chat completion response.
Extracts content from the message object within choices, handling the nested structure specific to chat completion endpoints.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
arguments | GenerationRequestArguments | The request arguments that were sent | required |
response | dict | Complete API response containing choices and usage data | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with extracted content and metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_streaming(request, arguments)
Compile accumulated streaming chat completion content into a final response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with concatenated content and metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
format(data, history=None, **kwargs)
Format the chat completion generation request into the appropriate structure.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
data | GenerationRequest | The generation request to format | required |
history | HistoryT[GenerationRequest, GenerationResponse] | None | Prior (request, response) pairs in the conversation | None |
**kwargs | Additional keyword arguments for request formatting | {} |
Returns:
| Type | Description |
|---|---|
GenerationRequestArguments | The formatted request arguments |
Source code in src/guidellm/backends/openai/request_handlers.py
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OpenAIHTTPBackend
Bases: Backend
HTTP backend for OpenAI-compatible servers.
Supports OpenAI API, vLLM servers, and other compatible endpoints with text/chat completions, streaming, authentication, and multimodal inputs. Handles request formatting, response parsing, error handling, and token usage tracking with flexible parameter customization.
Example: :: backend_args = OpenAIHTTPBackendArgs( target="http://localhost:8000", model="gpt-3.5-turbo", api_key="your-api-key", ) backend = OpenAIHTTPBackend(backend_args)
await backend.process_startup()
async for response, request_info in backend.resolve(request, info):
process_response(response)
await backend.process_shutdown()
Source code in src/guidellm/backends/openai/http.py
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__init__(arguments)
Initialize OpenAI HTTP backend with server configuration.
Source code in src/guidellm/backends/openai/http.py
available_models() async
Get available models from the target server.
Returns:
| Type | Description |
|---|---|
list[str] | List of model identifiers |
Raises:
| Type | Description |
|---|---|
httpx.HTTPError | If models endpoint returns an error |
RuntimeError | If backend is not initialized |
Source code in src/guidellm/backends/openai/http.py
default_model() async
Get the default model for this backend.
Returns:
| Type | Description |
|---|---|
str | Model name or None if no model is available |
Source code in src/guidellm/backends/openai/http.py
process_shutdown() async
Clean up HTTP client and backend resources.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend was not properly initialized |
httpx.RequestError | If HTTP client cannot be closed |
Source code in src/guidellm/backends/openai/http.py
process_startup() async
Initialize HTTP client and backend resources.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend is already initialized |
httpx.RequestError | If HTTP client cannot be created |
Source code in src/guidellm/backends/openai/http.py
resolve(request, request_info, history=None) async
Process generation request and yield progressive responses.
Handles request formatting, timing tracking, API communication, and response parsing with streaming support.
:yields: Tuples of (response, updated_request_info) as generation progresses
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Generation request with content and parameters | required |
request_info | RequestInfo | Request tracking info updated with timing metadata | required |
history | list[tuple[GenerationRequest, GenerationResponse | None]] | None | Conversation history (currently not supported) | None |
Raises:
| Type | Description |
|---|---|
NotImplementedError | If history is provided |
RuntimeError | If backend is not initialized |
ValueError | If request type is unsupported |
Source code in src/guidellm/backends/openai/http.py
validate() async
Validate backend connectivity and configuration.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend cannot connect or validate configuration |
Source code in src/guidellm/backends/openai/http.py
OpenAIRequestHandler
Bases: Protocol
Protocol for handling OpenAI request endpoint
Defines the interface to format the request for a given endpoint and to process both streaming and non-streaming responses from backend APIs, converting them into standardized GenerationResponse objects with consistent metrics extraction.
Source code in src/guidellm/backends/openai/request_handlers.py
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last_iteration_had_content property
Whether the last chunk carried output (text/tool-call) tokens, not solely reasoning tokens.
Used by the HTTP streaming loop to detect the first output token for TTFOT measurement.
Returns:
| Type | Description |
|---|---|
bool | True if the last chunk carried output tokens, not solely reasoning tokens. |
add_streaming_line(line)
Process a single line from a streaming response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
line | str | Raw line from the streaming response | required |
Returns:
| Type | Description |
|---|---|
int | None | 1 if content was updated, 0 if line was ignored, None if done |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_non_streaming(request, arguments, response)
Process a complete non-streaming API response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
response | Any | Raw API response data from the backend | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with extracted metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_streaming(request, arguments)
Compile accumulated streaming data into a final response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with extracted metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
format(data, history=None, **kwargs)
Format the generation request into the appropriate structure for the backend API.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
data | GenerationRequest | The generation request to format | required |
history | HistoryT[GenerationRequest, GenerationResponse] | None | Prior (request, response) pairs in the conversation | None |
**kwargs | Additional keyword arguments for request formatting | {} |
Returns:
| Type | Description |
|---|---|
GenerationRequestArguments | The formatted request arguments |
Source code in src/guidellm/backends/openai/request_handlers.py
post_validation(response)
Validate a compiled response before returning it.
Default implementation is permissive (no-op). Handlers override this to reject responses that lack usable output for their endpoint type.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
response | GenerationResponse | The compiled generation response to validate. | required |
Raises:
| Type | Description |
|---|---|
ValueError | If the response is unusable. |
Source code in src/guidellm/backends/openai/request_handlers.py
OpenAIRequestHandlerFactory
Bases: RegistryMixin[type[OpenAIRequestHandler]]
Factory for registering and creating OpenAI request handlers by request type.
Registry-based system for associating handler classes with specific API types, enabling automatic selection of the appropriate handler for processing responses from different generation services.
Source code in src/guidellm/backends/openai/request_handlers.py
create(request_type, handler_overrides=None) classmethod
Create a request handler class for the given request type.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request_type | str | The type of generation request (e.g., "/chat/completions") | required |
handler_overrides | dict[str, type[OpenAIRequestHandler]] | None | Optional mapping of request types to handler classes to override the default registry by checking first and then falling back to the registered handlers. | None |
Returns:
| Type | Description |
|---|---|
OpenAIRequestHandler | The corresponding instantiated GenerationResponseHandler |
Raises:
| Type | Description |
|---|---|
ValueError | When no handler is registered for the request type |
Source code in src/guidellm/backends/openai/request_handlers.py
OpenAIWebSocketBackend
Bases: Backend
WebSocket client for realtime (streaming) audio transcription.
Connects to a vLLM-style /v1/realtime WebSocket, streams PCM16 audio chunks, and maps transcription.* events into GenerationResponse with timings.
Example: :: args = OpenAIWebSocketBackendArgs( target="http://localhost:8000", model="my-model", ) backend = OpenAIWebSocketBackend(args)
await backend.process_startup()
async for response, request_info in backend.resolve(request, info):
...
await backend.process_shutdown()
Source code in src/guidellm/backends/openai/websocket.py
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info property
Return a snapshot of backend configuration for logging or debugging.
Returns:
| Type | Description |
|---|---|
dict[str, Any] | Dict of target, model, WebSocket path, timeouts, and validation opts. |
websocket_path property
HTTP path segment on the host used for the WebSocket URL.
Returns:
| Type | Description |
|---|---|
str | Resolved path from |
__init__(arguments)
Initialize the WebSocket backend from validated args.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
arguments | OpenAIWebSocketBackendArgs | Typed configuration including target, model, and paths. | required |
Source code in src/guidellm/backends/openai/websocket.py
available_models() async
List model IDs from GET /v1/models on the HTTP target.
Returns:
| Type | Description |
|---|---|
list[str] | Model identifiers from the OpenAI-style payload. |
Raises:
| Type | Description |
|---|---|
RuntimeError | If the client is not started or the response is invalid. |
Source code in src/guidellm/backends/openai/websocket.py
default_model() async
Return the configured model, or the first from available_models if empty.
Returns:
| Type | Description |
|---|---|
str | Non-empty model name when discoverable; otherwise |
Source code in src/guidellm/backends/openai/websocket.py
process_shutdown() async
Close the HTTP client and reset process-local state.
Raises:
| Type | Description |
|---|---|
RuntimeError | If the backend was not started. |
Source code in src/guidellm/backends/openai/websocket.py
process_startup() async
Create the shared :class:httpx.AsyncClient used for health and /v1/models.
Raises:
| Type | Description |
|---|---|
RuntimeError | If the backend was already started in this process. |
Source code in src/guidellm/backends/openai/websocket.py
resolve(request, request_info, history=None) async
Stream one realtime transcription over WebSocket for a single audio column.
Delegates event interpretation to the registered :class:~guidellm.backends.openai.request_handlers.OpenAIWSRequestHandler via add_streaming_event / compile_streaming, while this method handles only I/O and timing.
:yields: (response_or_none, request_info) until stream completion.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Must contain exactly one | required |
request_info | RequestInfo | Timings updated as events arrive. | required |
history | list[tuple[GenerationRequest, GenerationResponse | None]] | None | Not supported; raises | None |
Raises:
| Type | Description |
|---|---|
NotImplementedError | If |
RuntimeError | If the client is not started, model is missing, or the peer returns an error event. |
Source code in src/guidellm/backends/openai/websocket.py
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validate() async
Run the configured HTTP probe (same semantics as openai_http).
Raises:
| Type | Description |
|---|---|
RuntimeError | If the client is not started or the probe fails. |
Source code in src/guidellm/backends/openai/websocket.py
OpenAIWebSocketBackendArgs
Bases: BackendArgs
Typed configuration for :class:OpenAIWebSocketBackend.
Source code in src/guidellm/backends/openai/websocket.py
strip_target(value) classmethod
Strip trailing slashes and /v1 suffix from the target URL.
validate_request_format(v) classmethod
Validate request_format against allowed WebSocket paths.
Source code in src/guidellm/backends/openai/websocket.py
TextCompletionsRequestHandler
Bases: OpenAIRequestHandler
Request handler for OpenAI-style legacy completion endpoints.
Processes responses from text completion APIs that return generated text in the 'choices' array with 'text' fields. Handles both streaming and non-streaming responses, extracting usage metrics for input and output tokens.
Example: :: handler = TextCompletionsResponseHandler() response = handler.compile_non_streaming(request, api_response)
Source code in src/guidellm/backends/openai/request_handlers.py
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last_iteration_had_content property
Text completions (/v1/completions) have no reasoning concept, so every token is content. ChatCompletionsRequestHandler and ResponsesRequestHandler override this with a tracked flag that starts False and only becomes True when a content or tool call delta arrives.
Returns:
| Type | Description |
|---|---|
bool | Always True for the text completions base class |
__init__()
Initialize the text completions response handler.
Sets up internal state for accumulating streaming response data including text chunks and usage metrics.
Source code in src/guidellm/backends/openai/request_handlers.py
add_streaming_line(line)
Process a single line from a text completion streaming response.
Parses Server-Sent Events (SSE) formatted lines, extracting text content and usage metrics. Accumulates text chunks for final response compilation.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
line | str | Raw SSE line from the streaming response | required |
Returns:
| Type | Description |
|---|---|
int | None | 1 if text content was extracted, 0 if line ignored, None if done |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_non_streaming(request, arguments, response)
Process a complete text completion response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
response | dict | Complete API response containing choices and usage data | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with extracted text and metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
compile_streaming(request, arguments)
Compile accumulated streaming text chunks into a final response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request | required |
Returns:
| Type | Description |
|---|---|
GenerationResponse | Standardized GenerationResponse with concatenated text and metrics |
Source code in src/guidellm/backends/openai/request_handlers.py
extract_choices_and_usage(response)
Extract choices and usage data from the API response.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
response | dict | Complete API response containing choices and usage data | required |
Returns:
| Type | Description |
|---|---|
tuple[list[dict], dict[str, int | dict[str, int]]] | Tuple of choices list and usage dictionary |
Source code in src/guidellm/backends/openai/request_handlers.py
extract_line_data(line)
Extract JSON data from a streaming response line.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
line | str | Raw line from the streaming response | required |
Returns:
| Type | Description |
|---|---|
dict[str, Any] | None | Parsed JSON data as dictionary, or None if line indicates completion |
Source code in src/guidellm/backends/openai/request_handlers.py
extract_metrics(usage, text)
Extract input and output usage metrics from API response usage data.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
usage | dict[str, int | dict[str, int]] | None | Usage data dictionary from API response | required |
text | str | None | Generated text for calculating word and character counts. None means text is not applicable (metrics will be None); empty string means text was applicable but empty (metrics will be 0). | required |
Returns:
| Type | Description |
|---|---|
tuple[UsageMetrics, UsageMetrics] | Tuple of input_metrics and output_metrics as UsageMetrics objects |
Source code in src/guidellm/backends/openai/request_handlers.py
format(data, history=None, **kwargs)
Format the text completion generation request into the appropriate structure.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
data | GenerationRequest | The generation request to format | required |
**kwargs | Additional keyword arguments for request formatting | {} |
Returns:
| Type | Description |
|---|---|
GenerationRequestArguments | The formatted request arguments |
Source code in src/guidellm/backends/openai/request_handlers.py
post_validation(response)
Reject responses with no text, tool calls, or output tokens.
VLLMPythonBackend
Bases: Backend
Python API backend for VLLM inference engine.
Engine parameters not set in vllm_config use vLLM's AsyncEngineArgs defaults. Example: :: backend = VLLMPythonBackend(model="meta-llama/Llama-2-7b-chat-hf") # Or: vllm_config={"tensor_parallel_size": 1, "gpu_memory_utilization": 0.9}
await backend.process_startup()
async for response, request_info in backend.resolve(request, info):
process_response(response)
await backend.process_shutdown()
Source code in src/guidellm/backends/vllm_python/vllm.py
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processes_limit property
Limits VLLM Python to a single process, since it starts up an entire VLLM engine.
__init__(arguments)
Initialize VLLM Python backend with model and configuration.
Source code in src/guidellm/backends/vllm_python/vllm.py
available_models() async
Get available models from this backend.
Returns:
| Type | Description |
|---|---|
list[str] | List containing the configured model identifier |
Source code in src/guidellm/backends/vllm_python/vllm.py
backend_args() classmethod
default_model() async
Get the default model for this backend.
Returns:
| Type | Description |
|---|---|
str | Model name or identifier |
process_shutdown() async
Clean up VLLM AsyncLLMEngine instance and resources.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend was not properly initialized |
Source code in src/guidellm/backends/vllm_python/vllm.py
process_startup() async
Initialize VLLM AsyncLLMEngine instance with configured parameters.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend is already initialized |
Source code in src/guidellm/backends/vllm_python/vllm.py
resolve(request, request_info, history=None) async
Process generation request and yield a single response.
Resolves the request (chat template, placeholders, multimodal data), then runs async generation via AsyncLLMEngine. For streaming, records per-token timings. In both cases the caller receives exactly one (response, request_info) pair.
:yields: Single tuple of (response, updated_request_info)
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Generation request with content and parameters | required |
request_info | RequestInfo | Request tracking info updated with timing metadata | required |
history | list[tuple[GenerationRequest, GenerationResponse]] | None | Conversation history (currently not supported) | None |
Raises:
| Type | Description |
|---|---|
NotImplementedError | If history is provided |
RuntimeError | If backend is not initialized |
Source code in src/guidellm/backends/vllm_python/vllm.py
validate() async
Validate backend readiness by attempting a test generation.
Raises:
| Type | Description |
|---|---|
RuntimeError | If backend cannot generate or is not initialized |
Source code in src/guidellm/backends/vllm_python/vllm.py
VLLMResponseHandler
Stateless response builder for the vLLM Python backend.
Converts (text, usage dict) pairs into GenerationResponse with proper UsageMetrics. All methods are static; no per-request accumulation state.
Source code in src/guidellm/backends/vllm_python/vllm_response.py
build_response(request, text, usage, response_id=None) staticmethod
Build a GenerationResponse from text and usage extracted from vLLM output.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
request | GenerationRequest | Original generation request (provides request_id) | required |
text | str | Generated text | required |
usage | dict[str, int] | None | Token usage dict (prompt_tokens, completion_tokens, total_tokens) | required |
response_id | str | None | Optional response/request ID from vLLM | None |
Returns:
| Type | Description |
|---|---|
GenerationResponse | GenerationResponse with text and metrics |