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This SDK documentation applies to version 0.19.20 and earlier. The Build SDK will be deprecated and replaced with version 1.0.0 of the SDK (see our changelog for more details). Please migrate to the new SDK.

Resource types

The SDK currently supports four types of resources: LLM, Dataset, SupervisedFineTuningJob, and BatchInferenceJob.

LLM

Properties:
  • deployment_name str - The full name of the deployment (e.g., accounts/my-account/deployments/my-custom-deployment)
  • deployment_display_name str - The display name of the deployment, defaults to the filename where the LLM was instantiated unless otherwise specified
  • deployment_url str - The URL to view the deployment in the Fireworks dashboard
  • temperature float - The temperature for generation
  • model str - The model associated with this LLM (e.g., accounts/fireworks/models/llama-v3p2-3b-instruct)
  • base_deployment_name str - If a LoRA addon, the deployment name of the base model deployment
  • peft_base_model str - If this is a LoRA addon, the base model identifier (e.g., accounts/fireworks/models/llama-v3p2-3b-instruct)
  • addons_enabled bool - Whether LoRA addons are enabled for this LLM
  • model_id str - The identifier used under the hood to query this model (e.g., accounts/my-account/deployments/my-deployment-12345678)
  • deployment_id str - The deployment ID (e.g., my-custom-deployment)
  • base_deployment_id str - The base deployment ID for LoRA addons
  • perf_metrics_in_response bool - Whether performance metrics are included in responses

Instantiation

The LLM(*args, **kwargs) class constructor initializes a new LLM instance.

Required Arguments

  • model str - The model identifier to use (e.g., accounts/fireworks/models/llama-v3p2-3b-instruct)
  • deployment_type str - The type of deployment to use. Must be one of:
    • "serverless": Uses Fireworks’ shared serverless infrastructure
    • "on-demand": Uses dedicated resources for your deployment
    • "auto": Automatically selects the most cost-effective option (recommended for experimentation)
    • "on-demand-lora": For LoRA addons that require dedicated resources

Optional Arguments

Deployment Configuration
  • id str, optional - Deployment ID to identify the deployment. Required when deployment_type is “on-demand”. Can be any simple string (e.g., "my-deployment") - does not need to follow the format "accounts/account_id/deployments/deployment_id".
  • deployment_display_name str, optional - Display name for the deployment. Defaults to the filename where the LLM was instantiated. If a deployment with the same display name and model already exists, the SDK will try and re-use it.
  • base_id str, optional - Base deployment ID for LoRA addons. Required when deployment_type is “on-demand-lora”.
Authentication & API
  • api_key str, optional - Your Fireworks API key
  • base_url str, optional - Base URL for API calls. Defaults to “https://api.fireworks.ai/inference/v1
  • max_retries int, optional - Maximum number of retry attempts. Defaults to 10
Scaling Configuration
  • scale_up_window timedelta, optional - Time to wait before scaling up after increased load. Defaults to 1 second
  • scale_down_window timedelta, optional - Time to wait before scaling down after decreased load. Defaults to 1 minute
  • scale_to_zero_window timedelta, optional - Time of inactivity before scaling to zero. Defaults to 5 minutes
Hardware & Performance
  • accelerator_type str, optional - Type of GPU accelerator to use
  • region str, optional - Region for deployment
  • multi_region str, optional - Multi-region configuration
  • min_replica_count int, optional - Minimum number of replicas
  • max_replica_count int, optional - Maximum number of replicas
  • replica_count int, optional - Fixed number of replicas
  • accelerator_count int, optional - Number of accelerators per replica
  • precision str, optional - Model precision (e.g., “FP16”, “FP8”)
  • world_size int, optional - World size for distributed training
  • generator_count int, optional - Number of generators
  • disaggregated_prefill_count int, optional - Number of disaggregated prefill instances
  • disaggregated_prefill_world_size int, optional - World size for disaggregated prefill
  • max_batch_size int, optional - Maximum batch size for inference
  • max_peft_batch_size int, optional - Maximum batch size for PEFT operations
  • kv_cache_memory_pct int, optional - Percentage of memory for KV cache
Advanced Features
  • enable_addons bool, optional - Enable LoRA addons support
  • live_merge bool, optional - Enable live merging
  • draft_token_count int, optional - Number of tokens to generate per step for speculative decoding
  • draft_model str, optional - Model to use for speculative decoding
  • ngram_speculation_length int, optional - Length of previous input sequence for N-gram speculation
  • long_prompt_optimized bool, optional - Optimize for long prompts
  • temperature float, optional - Sampling temperature for generation
  • num_peft_device_cached int, optional - Number of PEFT devices to cache
Monitoring & Metrics
  • enable_metrics bool, optional - Enable metrics collection. Currently supports time to last token for non-streaming requests.
  • perf_metrics_in_response bool, optional - Include performance metrics in API responses
Additional Configuration
  • description str, optional - Description of the deployment
  • annotations dict[str, str], optional - Annotations for the deployment
  • cluster str, optional - Cluster identifier
  • enable_session_affinity bool, optional - Enable session affinity
  • direct_route_api_keys list[str], optional - List of API keys for direct routing
  • direct_route_type str, optional - Type of direct routing
  • direct_route_handle str, optional - Direct route handle

apply(wait: bool = True)

Ensures the deployment is ready and returns the deployment. Like Terraform apply, this will ensure the deployment is ready.

create_supervised_fine_tuning_job()

Creates a new supervised fine-tuning job and blocks until it is ready. See the SupervisedFineTuningJob section for details on the parameters. Returns:
  • An instance of SupervisedFineTuningJob.

reinforcement_step()

Performs a reinforcement learning step for training. This method creates a new model checkpoint by fine-tuning the current model on the provided dataset with reinforcement learning. Arguments:
  • dataset Dataset - The dataset containing training examples with rewards
  • output_model str - The name of the output model to create
  • lora_rank int, optional - Rank for LoRA fine-tuning. Defaults to 16
  • learning_rate float, optional - Learning rate for training. Defaults to 0.0001
  • max_context_length int, optional - Maximum context length for the model. Defaults to 8192
  • epochs int, optional - Number of training epochs. Defaults to 1
  • batch_size int, optional - Batch size for training. Defaults to 32768
  • accelerator_count int, optional - Number of accelerators to use for training. Defaults to 1
  • accelerator_type str, optional - Type of GPU accelerator to use for training. Supported values: "NVIDIA_A100_80GB", "NVIDIA_H100_80GB", "NVIDIA_H200_141GB". Defaults to "NVIDIA_A100_80GB"
When running on a trained LoRA (i.e., when using a model that is already a LoRA fine-tuned checkpoint), the training parameters (lora_rank, learning_rate, max_context_length, epochs, batch_size) must always be the same as those used in the original LoRA training. Changing these parameters when continuing training from a LoRA checkpoint is not supported and will result in an error.
Returns: Note: The output model name must not already exist. If a model with the same name exists, a ValueError will be raised.

delete_deployment(ignore_checks: bool = False, wait: bool = True)

Deletes the deployment associated with this LLM instance if one exists. Arguments:
  • ignore_checks bool, optional - Whether to ignore safety checks. Defaults to False.
  • wait bool, optional - Whether to wait for deletion to complete. Defaults to True.

get_time_to_last_token_mean()

Returns the mean time to last token for non-streaming requests. If no metrics are available, returns None. Returns:
  • A float representing the mean time to last token, or None if no metrics are available.

with_deployment_type()

Returns a new LLM instance with the specified deployment type. Arguments:
  • deployment_type str - The deployment type to use (“serverless”, “on-demand”, “auto”, or “on-demand-lora”). Note: For LoRA models, only “on-demand” and “on-demand-lora” are supported.
Returns:
  • A new LLM instance with the specified deployment type

with_temperature()

Returns a new LLM instance with the specified temperature. Arguments:
  • temperature float - The temperature for generation
Returns:
  • A new LLM instance with the specified temperature

with_perf_metrics_in_response()

Returns a new LLM instance with the specified performance metrics setting. Arguments:
  • perf_metrics_in_response bool - Whether to include performance metrics in responses
Returns:
  • A new LLM instance with the specified performance metrics setting

scale_to_zero()

Sends a request to scale the deployment to 0 replicas but does not wait for it to complete. Returns:
  • The deployment object, or None if no deployment exists

scale_to_1_replica()

Scales the deployment to at least 1 replica.

get_deployment()

Returns the deployment associated with this LLM instance, or None if no deployment exists. Returns:
  • The deployment object, or None if no deployment exists

is_peft_addon()

Checks if this LLM is a PEFT (Parameter-Efficient Fine-Tuning) addon. Returns:
  • True if this LLM is a PEFT addon, False otherwise

list_models()

Lists all models available to your account. Returns:
  • A list of model objects

get_model()

Gets the model object for this LLM’s model. Returns:
  • The model object, or None if the model doesn’t exist

is_available_on_serverless()

Checks if the model is available on serverless infrastructure. Returns:
  • True if the model is available on serverless, False otherwise

model_id()

Returns the model ID, which is the model name plus the deployment name if it exists. This is used for the “model” arg when calling the model. Returns:
  • The model ID string

list_fireworks_models()

Lists all models available on the Fireworks account. Returns:
  • A list of model objects from the Fireworks account

is_model_on_fireworks_account()

Checks if the model is on the Fireworks account. Arguments:
  • model str - The model identifier to check
Returns:
  • The model object if it exists on the Fireworks account, None otherwise

is_model_available_on_serverless()

Checks if a specific model is available on serverless infrastructure. Arguments:
  • model str - The model identifier to check
Returns:
  • True if the model is available on serverless, False otherwise

is_model_deployed_on_serverless_account()

Checks if a model is deployed on a serverless-enabled account. Arguments:
  • model SyncModel - The model object to check
Returns:
  • True if the model is deployed on a supported serverless account, False otherwise

completions.create() and completions.acreate()

Creates a text completion using the LLM. These methods are OpenAI compatible and follow the same interface as described in the OpenAI Completions API. Use create() for synchronous calls and acreate() for asynchronous calls. Arguments:
  • prompt str - The prompt to complete
  • stream bool, optional - Whether to stream the response. Defaults to False
  • images list[str], optional - List of image URLs for multimodal models
  • max_tokens int, optional - The maximum number of tokens to generate
  • logprobs int, optional - Number of log probabilities to return
  • echo bool, optional - Whether to echo the prompt in the response
  • temperature float, optional - Sampling temperature between 0 and 2. If not provided, uses the LLM’s default temperature
  • top_p float, optional - Nucleus sampling parameter
  • top_k int, optional - Top-k sampling parameter (must be between 0 and 100)
  • frequency_penalty float, optional - Frequency penalty for repetition
  • presence_penalty float, optional - Presence penalty for repetition
  • repetition_penalty float, optional - Repetition penalty
  • reasoning_effort str, optional - How much effort the model should put into reasoning
  • mirostat_lr float, optional - Mirostat learning rate
  • mirostat_target float, optional - Mirostat target entropy
  • n int, optional - Number of completions to generate
  • ignore_eos bool, optional - Whether to ignore end-of-sequence tokens
  • stop str or list[str], optional - Stop sequences
  • response_format dict, optional - An object specifying the format that the model must output
  • context_length_exceeded_behavior str, optional - How to handle context length exceeded
  • user str, optional - User identifier
  • extra_headers dict, optional - Additional headers to include in the request
  • **kwargs - Additional parameters supported by the OpenAI API
Returns:
  • Completion when stream=False (default)
  • Generator[Completion, None, None] when stream=True (sync version)
  • AsyncGenerator[Completion, None] when stream=True (async version)

chat.completions.create() and chat.completions.acreate()

Creates a chat completion using the LLM. These methods are OpenAI compatible and follow the same interface as described in the OpenAI Chat Completions API. Use create() for synchronous calls and acreate() for asynchronous calls. Note: The Fireworks chat completions API includes additional request and response fields beyond the standard OpenAI API. See the Fireworks Chat Completions API reference for the complete set of available parameters and response fields. Arguments:
  • messages list - A list of messages comprising the conversation so far
  • stream bool, optional - Whether to stream the response. Defaults to False
  • response_format dict, optional - An object specifying the format that the model must output
  • reasoning_effort str, optional - How much effort the model should put into reasoning
  • max_tokens int, optional - The maximum number of tokens to generate
  • temperature float, optional - Sampling temperature between 0 and 2. If not provided, uses the LLM’s default temperature. Note that temperature can also be set once during LLM instantiation if preferred
  • tools list, optional - A list of tools the model may call
  • extra_headers dict, optional - Additional headers to include in the request
  • **kwargs - Additional parameters supported by the OpenAI API
Returns:
  • ChatCompletion when stream=False (default)
  • Generator[ChatCompletionChunk, None, None] when stream=True (sync version)
  • AsyncGenerator[ChatCompletionChunk, None] when stream=True (async version)
For details on the ChatCompletion object structure, see the OpenAI Chat Completion Object documentation. For the ChatCompletionChunk object structure used in streaming, see the OpenAI Chat Streaming documentation.

Dataset

The Dataset class provides a convenient way to manage datasets for fine-tuning on Fireworks. It offers smart features like automatic naming and uploading of datasets. You do not instantiate a Dataset object directly. Instead, you create a Dataset object by using one of the class methods below. Properties:
  • name str - The full name of the dataset (e.g., accounts/my-account/datasets/dataset-12345-my-data)
  • id str - The dataset identifier (e.g., dataset-12345-my-data)
  • url str - The URL to view the dataset in the Fireworks dashboard

from_list()

Creates a Dataset from a list of training examples. Each example should be compatible with OpenAI’s chat completion format.

from_file()

Creates a Dataset from a local JSONL file. The file should contain training examples in OpenAI’s chat completion format.

from_string()

Creates a Dataset from a string containing JSONL-formatted training examples.

from_id()

Creates a Dataset from an existing dataset ID on Fireworks.

sync()

Uploads the dataset to Fireworks if it doesn’t already exist. This method automatically:
  1. Checks if a dataset with the same content hash already exists
  2. If it exists, skips the upload to avoid duplicates
  3. If it doesn’t exist, creates and uploads the dataset to Fireworks
  4. Validates the dataset after upload

delete()

Deletes the dataset from Fireworks.

head(n: int = 5, as_dataset: bool = False)

Returns the first n rows of the dataset. Arguments:
  • n int, optional - Number of rows to return. Defaults to 5.
  • as_dataset bool, optional - If True, return a Dataset object; if False, return a list. Defaults to False.
Returns:
  • list or Dataset - List of dictionaries if as_dataset=False, Dataset object if as_dataset=True

create_evaluation_job(reward_function: Callable, samples: Optional[int] = None)

Creates an evaluation job using a reward function for this dataset. Arguments:
  • reward_function Callable - A callable decorated with @reward_function
  • samples int, optional - Optional number of samples to evaluate (creates a subset dataset)
Returns:
  • EvaluationJob - The created evaluation job

preview_evaluator(reward_function: Callable, samples: Optional[int] = None)

Previews the evaluator for the dataset. Arguments:
  • reward_function Callable - A callable decorated with @reward_function
  • samples int, optional - Optional number of samples to preview
Returns:
  • SyncPreviewEvaluatorResponse - Preview response from the evaluator

Data Format

The Dataset class expects data in OpenAI’s chat completion format. Each training example should be a JSON object with a messages array containing message objects. Each message object should have:
  • role: One of "system", "user", or "assistant"
  • content: The message content as a string
Example format:

SupervisedFineTuningJob

The SupervisedFineTuningJob class manages fine-tuning jobs on Fireworks. It provides a convenient interface for creating, monitoring, and managing fine-tuning jobs.
Properties:
  • output_model str - The identifier of the output model (e.g., accounts/my-account/models/my-finetuned-model)
  • output_llm LLM - An LLM instance associated with the output model
  • id str - The job ID
  • display_name str - The display name of the job
  • name str - The full name of the job
  • url str - The URL to view the job in the Fireworks dashboard

Instantiation

You do not need to directly instantiate a SupervisedFineTuningJob object. Instead, you should use the .create_supervised_fine_tuning_job() method on the LLM object and pass in the following required and optional arguments.

Required Arguments

  • display_name str - A unique name for the fine-tuning job. Must only contain lowercase a-z, 0-9, and hyphen (-).
  • dataset_or_id Union[Dataset, str] - The dataset to use for fine-tuning, either as a Dataset object or dataset ID

Optional Arguments

Training Configuration
  • epochs int, optional - Number of training epochs
  • learning_rate float, optional - Learning rate for training
  • lora_rank int, optional - Rank for LoRA fine-tuning
  • jinja_template str, optional - Template for formatting training examples
  • early_stop bool, optional - Whether to enable early stopping
  • max_context_length int, optional - Maximum context length for the model
  • base_model_weight_precision str, optional - Precision for base model weights
  • batch_size int, optional - Batch size for training
Hardware Configuration
  • accelerator_type str, optional - Type of GPU accelerator to use
  • accelerator_count int, optional - Number of accelerators to use
  • is_turbo bool, optional - Whether to use turbo mode for faster training
  • region str, optional - Region for deployment
  • nodes int, optional - Number of nodes to use
Evaluation & Monitoring
  • evaluation_dataset str, optional - Dataset ID to use for evaluation
  • eval_auto_carveout bool, optional - Whether to automatically carve out evaluation data
  • wandb_config WandbConfig, optional - Configuration for Weights & Biases integration
Job Management
  • output_model str, optional - The name of the output model to create. If not provided, it will be the same as the display_name argument.

sync()

Creates the job if it doesn’t exist, otherwise returns the existing job. If previous job failed, deletes it and creates a new one. Returns:
  • SupervisedFineTuningJob - The synced job object

wait_for_completion()

Polls the job status until it is complete and returns the job object. Returns:
  • SupervisedFineTuningJob - The completed job object

await_for_completion()

Asynchronously polls the job status until it is complete and returns the job object. Returns:
  • SupervisedFineTuningJob - The completed job object

delete()

Deletes the job.

adelete()

Asynchronously deletes the job.

ReinforcementStep

The ReinforcementStep class represents a reinforcement learning training step. It provides methods to monitor and manage the training process.
Properties:
  • state str - The current state of the training job (e.g., “JOB_STATE_RUNNING”, “JOB_STATE_COMPLETED”)
  • output_model str - The identifier of the output model (e.g., accounts/my-account/models/my-improved-model)
  • is_completed bool - Whether the training job has completed successfully

get()

Retrieves the current state of the training job from the server. Returns:
  • A ReinforcementStep object with updated state, or None if the job no longer exists

raise_if_bad_state()

Raises a RuntimeError if the job is in a failed, cancelled, or otherwise bad state. This is useful for error handling during training. Raises:
  • RuntimeError - If the job is in a bad state (failed, cancelled, expired, etc.)

Usage Example

Iterative Reinforcement Learning Workflow

The reinforcement_step method is designed to support iterative reinforcement learning workflows. Here’s a complete example showing how to perform multiple reinforcement learning steps:
This workflow demonstrates the iterative nature of reinforcement learning, where each step:
  1. Uses the current model snapshot to generate rollouts
  2. For each prompt, generates multiple responses (required for Policy Optimization)
  3. Evaluates each response and computes rewards
  4. Creates a dataset with the rollouts and rewards (each sample contains multiple generations)
  5. Performs a reinforcement learning step to create an improved model
Each sample in the dataset must contain multiple trajectories for the same prompt. This is required for policy optimization to work.

BatchInferenceJob

The BatchInferenceJob class provides a convenient way to manage batch inference jobs on Fireworks. It allows you to perform bulk asynchronous inference on large datasets, reducing costs by up to 50%.
Properties:
  • name str - The full name of the batch inference job (e.g., accounts/my-account/batchInferenceJobs/test-job-123)
  • id str - The job identifier (e.g., test-job-123)
  • model str - The model used for inference
  • input_dataset_id str - The input dataset identifier
  • output_dataset_id str - The output dataset identifier
  • state str - The current state of the job
  • created_by str - Email of the user who created the job
  • create_time str - Creation timestamp
  • update_time str - Last update timestamp

create()

Creates a new batch inference job. Arguments:
  • model str - The model to use for inference (e.g., llama-v3p1-8b-instruct or accounts/fireworks/models/llama-v3p1-8b-instruct)
  • input_dataset_id str - The input dataset ID containing JSONL formatted requests
  • output_dataset_id str, optional - The output dataset ID. If not provided, one will be auto-generated
  • job_id str, optional - The job ID. If not provided, one will be auto-generated
  • display_name str, optional - Display name for the job
  • inference_parameters dict, optional - Dict of inference parameters:
    • max_tokens int - Maximum number of tokens to generate
    • temperature float - Sampling temperature (0-2)
    • top_p float - Top-p sampling parameter
    • top_k int - Top-k sampling parameter
    • n int - Number of completions per request
    • extra_body str - Additional parameters as JSON string
  • api_key str, optional - The API key to use
Returns:
  • A BatchInferenceJob object

get()

Retrieves a batch inference job by its ID. Arguments:
  • job_id str - The job ID or full resource name
  • account str - Account ID
  • api_key str, optional - The API key to use
Returns:
  • A BatchInferenceJob object if found, None otherwise

list()

Lists batch inference jobs in an account. Arguments:
  • account str - Account ID
  • api_key str, optional - The API key to use
  • page_size int, optional - Number of jobs to return per page. Defaults to 50
Returns:
  • A list of BatchInferenceJob objects

delete()

Deletes a batch inference job. Arguments:
  • job_id str - The job ID or full resource name
  • account str - Account ID
  • api_key str, optional - The API key to use

to_dict()

Converts a batch inference job proto to a friendly dictionary representation. Arguments:
  • proto BatchInferenceJob - The batch inference job proto object
Returns:
  • A dictionary with human-readable field values