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Python API Reference

Create a new LLM client with simple scalar configuration.

This is the primary binding entry-point. All parameters except api_key are optional — omitting them uses the same defaults as ClientConfigBuilder.

Errors:

Returns LiterLlmError if the underlying HTTP client cannot be constructed, or if the resolved provider configuration is invalid.

Signature:

def create_client(api_key: str, base_url: str = None, timeout_secs: int = None, max_retries: int = None, model_hint: str = None) -> DefaultClient

Example:

result = create_client("value", base_url="value", timeout_secs=42, max_retries=42, model_hint="value")

Parameters:

Name Type Required Description
api_key str Yes The api key
base_url str | None No The base url
timeout_secs int | None No The timeout secs
max_retries int | None No The max retries
model_hint str | None No The model hint

Returns: DefaultClient

Errors: Raises LiterLlmError.


Create a new LLM client from a JSON string.

The JSON object accepts the same fields as liter-llm.toml (snake_case).

Errors:

Returns LiterLlmError.BadRequest if json is not valid JSON or contains unknown fields.

Signature:

def create_client_from_json(json: str) -> DefaultClient

Example:

result = create_client_from_json("value")

Parameters:

Name Type Required Description
json str Yes The json

Returns: DefaultClient

Errors: Raises LiterLlmError.


Encode bytes as a base64 data URL: data:<mime>;base64,<b64>.

mime defaults to IMAGE_PNG when None.

Signature:

def encode_data_url(bytes: bytes, mime: str = None) -> str

Example:

result = encode_data_url(b"data", mime="value")

Parameters:

Name Type Required Description
bytes bytes Yes The bytes
mime str | None No The mime

Returns: str


Decode a base64 data URL into DecodedDataUrl.

Returns None for:

  • Non-data URLs (strings that do not start with "data:").
  • Malformed prefixes (missing ";base64," marker).
  • Invalid base64 payloads.

The returned MIME string is extracted verbatim from the URL prefix — it is not validated or normalised.

Signature:

def decode_data_url(url: str) -> DecodedDataUrl | None

Example:

result = decode_data_url("value")

Parameters:

Name Type Required Description
url str Yes The URL to fetch

Returns: DecodedDataUrl | None


Register a custom provider in the global runtime registry.

The provider will be checked before all built-in providers during model detection. If a provider with the same name already exists it is replaced.

Errors:

Returns an error if the config is invalid (empty name, empty base_url, or no model prefixes).

Signature:

def register_custom_provider(config: CustomProviderConfig) -> None

Example:

register_custom_provider(CustomProviderConfig())

Parameters:

Name Type Required Description
config CustomProviderConfig Yes The configuration options

Returns: No return value.

Errors: Raises LiterLlmError.


Remove a previously registered custom provider by name.

Returns True if a provider with the given name was found and removed, False if no such provider existed.

Errors:

Returns an error if the custom-provider registry cannot be updated.

Signature:

def unregister_custom_provider(name: str) -> bool

Example:

result = unregister_custom_provider("value")

Parameters:

Name Type Required Description
name str Yes The name

Returns: bool

Errors: Raises LiterLlmError.


Return the capability flags for a named provider.

Performs an O(n) linear scan over the embedded registry (165 entries). Returns an owned value so bindings can pass capability data without borrowing registry internals.

For unknown provider_name values the function returns an all-False sentinel so callers never need to handle Option.

Signature:

def capabilities(provider_name: str) -> ProviderCapabilities

Example:

result = capabilities("value")

Parameters:

Name Type Required Description
provider_name str Yes The provider name

Returns: ProviderCapabilities


Return all provider configs from the registry.

Useful for tooling, documentation generation, or runtime enumeration. Returns the public ProviderConfig slice (without capability flags). To query capability flags for a specific provider use capabilities.

Signature:

def all_providers() -> list[ProviderConfig]

Example:

result = all_providers()

Returns: list[ProviderConfig]

Errors: Raises LiterLlmError.


Return the set of complex provider names.

Complex providers require custom auth/routing logic beyond simple bearer tokens (e.g. AWS Bedrock SigV4, Vertex AI OAuth2).

The returned reference points into the static registry — no allocation.

Signature:

def complex_provider_names() -> list[str]

Example:

result = complex_provider_names()

Returns: list[str]

Errors: Raises LiterLlmError.


Calculate the estimated cost of a completion given a model name and token counts.

Returns None if the model is not present in the embedded pricing registry. Returns Some(cost_usd) otherwise, where the value is in US dollars.

When an exact model name match is not found, progressively shorter prefixes are tried by stripping from the last - or . separator. For example, gpt-4-0613 will match gpt-4 if no gpt-4-0613 entry exists.

Signature:

def completion_cost(model: str, prompt_tokens: int, completion_tokens: int) -> float | None

Example:

result = completion_cost("value", 42, 42)

Parameters:

Name Type Required Description
model str Yes The model
prompt_tokens int Yes The prompt tokens
completion_tokens int Yes The completion tokens

Returns: float | None


Calculate the estimated cost of a completion, accounting for cached (cache-hit) prompt tokens billed at the provider’s discounted rate.

cached_tokens is the count of prompt tokens served from the provider’s prompt cache. It must be <= prompt_tokens (cached tokens are a subset of the prompt). The non-cached portion is billed at input_cost_per_token and the cached portion at cache_read_input_token_cost when the model has cache pricing; otherwise the entire prompt is billed at the regular input rate.

Returns None if the model is not present in the embedded pricing registry, mirroring completion_cost.

When the model has ModelPricing.tiers, the tier whose min_context_tokens is the highest value <= prompt_tokens supplies the input/output/cache rates for the whole call; models without tiers (or when prompt_tokens is below every tier threshold) use the base rates unchanged, matching the original flat-rate behaviour.

Signature:

def completion_cost_with_cache(model: str, prompt_tokens: int, cached_tokens: int, completion_tokens: int) -> float | None

Example:

result = completion_cost_with_cache("value", 42, 42, 42)

Parameters:

Name Type Required Description
model str Yes The model
prompt_tokens int Yes The prompt tokens
cached_tokens int Yes The cached tokens
completion_tokens int Yes The completion tokens

Returns: float | None


Look up FFI-friendly pricing and capability metadata for a model.

Returns None if the model is not present in the active pricing registry. Uses the same exact-match-then-prefix-fallback resolution as model_pricing; unlike model_pricing, the result is an owned ModelInfo value safe to hand across the FFI boundary.

When a runtime catalog refresh has succeeded, this reflects the refreshed (overlay) catalog; otherwise it reflects the embedded catalog. See model_pricing for the embedded-only alternative.

Signature:

def model_info(model: str) -> ModelInfo | None

Example:

result = model_info("value")

Parameters:

Name Type Required Description
model str Yes The model

Returns: ModelInfo | None


Remove all guardrails from the global registry.

Primarily useful in tests to reset state between test cases.

Panics:

Panics if the global registry lock is poisoned.

Signature:

def clear() -> None

Example:

clear()

Returns: No return value.


Count tokens in a text string using the tokenizer for the given model.

The tokenizer is resolved from the model name prefix (e.g. "gpt-4o" maps to the Xenova/gpt-4o HuggingFace tokenizer). Tokenizers are cached after first load.

Errors:

Returns LiterLlmError.BadRequest if the tokenizer cannot be loaded (e.g. network failure on first use) or if tokenization itself fails.

Signature:

def count_tokens(model: str, text: str) -> int

Example:

result = count_tokens("value", "value")

Parameters:

Name Type Required Description
model str Yes The model
text str Yes The text

Returns: int

Errors: Raises LiterLlmError.


Count tokens for a full ChatCompletionRequest.

Sums tokens across all message text contents plus a per-message overhead of ~4 tokens (for role, separators, and formatting metadata). Tool definitions and multimodal content parts (images, audio, documents) are not counted — only textual content contributes to the token total.

Errors:

Returns LiterLlmError.BadRequest if the tokenizer cannot be loaded or if tokenization fails for any message.

Signature:

def count_request_tokens(model: str, req: ChatCompletionRequest) -> int

Example:

result = count_request_tokens("value", ChatCompletionRequest())

Parameters:

Name Type Required Description
model str Yes The model
req ChatCompletionRequest Yes The chat completion request

Returns: int

Errors: Raises LiterLlmError.


Assert that current_len + incoming does not exceed limit.

Call this before appending incoming bytes to any buffer that must stay below limit. Returns Err(LiterLlmError.Streaming) on overflow and emits a tracing.warn! with context.

Signature:

def check_bound(context: str, current_len: int, incoming: int, limit: int) -> None

Example:

check_bound("value", 42, 42, 42)

Parameters:

Name Type Required Description
context str Yes The context
current_len int Yes The current len
incoming int Yes The incoming
limit int Yes The limit

Returns: No return value.

Errors: Raises LiterLlmError.


Install the ring crypto provider as the rustls process default, idempotently.

rustls 0.23+ removed the implicit default provider. This function installs ring once per process. Subsequent calls are no-ops. Calling it after another rustls crypto provider has already been installed is safe: the Err from install_default() is silently ignored.

Called automatically by every internal reqwest.Client constructor (auth providers, default HTTP client). Bindings and downstream consumers reach those constructors transitively, so no manual init is required.

WASM builds are exempt — the WASM target uses the browser/Node.js fetch API instead of rustls, so no crypto provider is needed.

Windows builds use native-tls (SChannel) via reqwest, so rustls is not present and no crypto provider installation is needed.

Signature:

def ensure_crypto_provider() -> None

Example:

ensure_crypto_provider()

Returns: No return value.


No-op on Windows: reqwest uses native-tls (SChannel), so no rustls provider installation is needed. All callers use the same call site regardless of platform.

Signature:

def ensure_crypto_provider() -> None

Example:

ensure_crypto_provider()

Returns: No return value.


Install the overlay registry from a raw catalog JSON string, bypassing the network and disk cache entirely.

Parses and flattens catalog_json with the same registry_from_catalog_str logic used for the embedded catalog and the network refresh path, then atomically swaps it in as the active overlay. A parse failure returns CatalogRefreshError.Parse and leaves any existing overlay untouched.

This is primarily a testable seam: it lets tests exercise overlay installation and the embedded/overlay fallback behavior in completion_cost / model_info without a real network call.

Signature:

def install_catalog_overlay_from_str(catalog_json: str) -> None

Example:

install_catalog_overlay_from_str("value")

Parameters:

Name Type Required Description
catalog_json str Yes The catalog json

Returns: No return value.

Errors: Raises CatalogRefreshError.


Clear the overlay registry, reverting completion_cost, completion_cost_with_cache, and model_info to the embedded catalog.

Primarily a test seam (see install_catalog_overlay_from_str); also usable by long-running processes that want to abandon a runtime refresh.

Signature:

def clear_catalog_overlay() -> None

Example:

clear_catalog_overlay()

Returns: No return value.


Refresh the runtime catalog overlay per config.

  • config.enabled == false: returns Ok(RefreshOutcome.Disabled) immediately. No network, filesystem, or overlay activity.

  • A fresh on-disk cache (age < config.ttl_seconds) exists at the resolved cache path (config.cache_path, or a default under std.env.temp_dir()): read + flatten it and install the overlay, returning Ok(RefreshOutcome.FromCache). No network request is made.

  • Otherwise: validate config.source_url uses https (CatalogRefreshError.InsecureUrl otherwise), fetch it, flatten it, install the overlay, best-effort write the raw JSON to the cache path (a cache write failure does not fail the refresh), and return Ok(RefreshOutcome.Fetched).

On any error return, the overlay is left untouched: the previously active registry (a prior successful overlay, or the embedded catalog if none was ever installed) remains in effect. This is what makes the feature air-gap-safe — an unreachable or invalid source_url never degrades completion_cost / model_info below embedded-catalog availability.

Signature:

def refresh_catalog(config: CatalogRefreshConfig) -> RefreshOutcome

Example:

result = refresh_catalog(CatalogRefreshConfig())

Parameters:

Name Type Required Description
config CatalogRefreshConfig Yes The configuration options

Returns: RefreshOutcome

Errors: Raises CatalogRefreshError.


Assistant’s response to a user message.

Field Type Default Description
content AssistantContent | None None The assistant’s response: plain text, structured parts, or absent. None is valid when the model replies with tool calls only.
name str | None None Optional name for the assistant.
tool_calls list\[ToolCall\] | None \[\] Tool calls the model wants to execute, if any.
refusal str | None None Refusal reason, if the model declined to respond per safety policies.
function_call FunctionCall | None None Deprecated legacy function_call field; retained for API compatibility.
reasoning_content str | None None Reasoning/thinking tokens returned by the provider, if any (e.g. DeepSeek R1, Qwen reasoning_content, or Anthropic extended thinking).

Return the assistant’s textual response, concatenating all Text parts if the content is structured.

Returns None for Refusal-only or OutputImage-only responses.

Signature:

def text(self) -> str | None

Example:

result = instance.text()

Returns: str | None

Return the refusal message, if the model declined to respond.

Checks both the top-level refusal field and any Refusal parts inside a structured content.

Signature:

def refusal_text(self) -> str | None

Example:

result = instance.refusal_text()

Returns: str | None

Return the model’s reasoning/thinking tokens, if the provider returned any.

Signature:

def reasoning_text(self) -> str | None

Example:

result = instance.reasoning_text()

Returns: str | None

Return all AssistantPart.OutputImage parts in the response.

Signature:

def output_images(self) -> list[ImageUrl]

Example:

result = instance.output_images()

Returns: list[ImageUrl]

Return all AssistantPart.OutputAudio parts in the response.

Signature:

def output_audio(self) -> list[AudioContent]

Example:

result = instance.output_audio()

Returns: list[AudioContent]


Audio content part for speech-capable models.

Field Type Default Description
data str Base64-encoded audio data.
format str Audio format (e.g., “wav”, “mp3”, “ogg”).

Auth configuration block.

Field Type Default Description
auth_type AuthType Auth scheme classification.
env_var str | None None Name of the environment variable that holds the API key (e.g. "OPENAI_API_KEY"). Holds the variable name, never the secret value.

Query parameters for listing batches.

Field Type Default Description
limit int | None None Maximum number of results to return. Defaults to 20.
after str | None None Pagination cursor: return results after this batch ID.

Response from listing batches.

Field Type Default Description
object str Object type (always "list").
data list\[BatchObject\] \[\] List of batch objects.
has_more bool | None None Whether more results are available.
first_id str | None None First batch ID in the result set (for pagination).
last_id str | None None Last batch ID in the result set (for pagination).

A batch job object.

Field Type Default Description
id str Unique batch ID.
object str Object type (always "batch").
endpoint str API endpoint (e.g., "/v1/chat/completions").
input_file_id str ID of the input file.
completion_window str Completion window (e.g., "24h").
status BatchStatus BatchStatus.VALIDATING Current job status.
output_file_id str | None None ID of the output file (present when completed).
error_file_id str | None None ID of the error file (present if some requests failed).
created_at int Unix timestamp of batch creation.
completed_at int | None None Unix timestamp of completion (if completed).
failed_at int | None None Unix timestamp of failure (if failed).
expired_at int | None None Unix timestamp of expiration (if expired).
request_counts BatchRequestCounts | None None Request processing counts.
metadata dict\[str, Any\] | None None Metadata attached to the batch.

Request processing counts for a batch.

Field Type Default Description
total int Total requests in the batch.
completed int Completed requests.
failed int Failed requests.

AWS Bedrock configuration.

All fields are optional; anything left unset falls back to the standard AWS environment variables (AWS_DEFAULT_REGION / AWS_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN, BEDROCK_CROSS_REGION).

Field Type Default Description
region str | None None AWS region (e.g. "us-east-1").
cross_region_prefix str | None None Cross-region inference profile prefix (e.g. "us").
access_key_id str | None None Explicit AWS access key ID.
secret_access_key str | None None Explicit AWS secret access key.
session_token str | None None Explicit AWS session token (temporary credentials).

Configuration for budget enforcement.

Field Type Default Description
global_limit float | None None Maximum total spend across all models, in USD. None means unlimited.
model_limits dict\[str, float\] {} Per-model spending limits in USD. Models not listed here are only constrained by global_limit.
enforcement Enforcement Enforcement.HARD Whether to reject requests or merely warn when a limit is exceeded.

Signature:

@staticmethod
def default() -> BudgetConfig

Example:

result = BudgetConfig.default()

Returns: BudgetConfig


Configuration for the response cache.

Field Type Default Description
max_entries int 256 Maximum number of cached entries.
ttl float 300000ms Time-to-live for each cached entry.
backend CacheBackend CacheBackend.MEMORY Storage backend to use.

Signature:

@staticmethod
def default() -> CacheConfig

Example:

result = CacheConfig.default()

Returns: CacheConfig


Plain-data configuration for refresh_catalog.

Deliberately FFI/binding-friendly: no Duration or PathBuf, just primitives that translate directly across language boundaries.

Field Type Default Description
enabled bool False Runtime catalog refresh is entirely opt-in: when False, refresh_catalog is a no-op that returns Ok(RefreshOutcome.Disabled) without touching the network, the filesystem, or the overlay registry.
source_url str Source URL to fetch catalog.json from. Must be https. Defaults to DEFAULT_CATALOG_URL; configurable so self-hosted mirrors work.
ttl_seconds int 86400 How long a cached catalog.json remains valid before a network refetch is attempted, in seconds.
cache_path str | None None Filesystem path for the on-disk cache. None uses a default path under std.env.temp_dir().

Signature:

@staticmethod
def default() -> CatalogRefreshConfig

Example:

result = CatalogRefreshConfig.default()

Returns: CatalogRefreshConfig


A streamed chunk of a chat completion response.

Field Type Default Description
id str Unique identifier for this stream.
object str Always "chat.completion.chunk" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not fail parsing.
created int Unix timestamp of chunk creation.
model str Model used to generate the chunk.
choices list\[StreamChoice\] \[\] Streaming choices (delta updates).
usage Usage | None None Token usage (typically only in the final chunk).
system_fingerprint str | None None Fingerprint of the system configuration (OpenAI-specific).
service_tier str | None None Service tier used (OpenAI-specific).

Chat completion request (compatible with OpenAI and similar APIs).

Field Type Default Description
model str Model ID (e.g., "gpt-4o-mini", "claude-3-5-sonnet").
messages list\[Message\] \[\] Conversation history from oldest to newest.
temperature float | None None Sampling temperature in \[0.0, 2.0\]. Higher increases randomness. Defaults to 1.0.
top_p float | None None Nucleus sampling parameter in \[0.0, 1.0\]. Lower is more focused.
n int | None None Number of chat completions to generate. Defaults to 1.
stream bool | None None Whether to stream the response. Managed by the client layer — do not set directly.
stop StopSequence | None None Stop sequence(s) that halt token generation.
max_tokens int | None None Max output tokens. Different from max_completion_tokens in some providers.
presence_penalty float | None None Presence penalty in \[-2.0, 2.0\]. Positive discourages repeated topics.
frequency_penalty float | None None Frequency penalty in \[-2.0, 2.0\]. Positive discourages repeated tokens.
logit_bias dict\[str, float\] | None {} Token bias map. Uses BTreeMap (sorted keys) for deterministic serialization order — important when hashing or signing requests.
user str | None None User identifier for request tracking and abuse detection.
tools list\[ChatCompletionTool\] | None \[\] Tools the model can invoke.
tool_choice ToolChoice | None None Tool usage mode (auto, required, none, or specific tool).
parallel_tool_calls bool | None None Whether the model can call multiple tools in parallel. Defaults to true.
response_format ResponseFormat | None None Output format constraint (text, JSON, JSON schema).
stream_options StreamOptions | None None Streaming options (e.g., include_usage).
seed int | None None Random seed for reproducible outputs. Provider support varies.
reasoning_effort ReasoningEffort | None None Reasoning effort level (minimal, low, medium, high, max) for extended-thinking models.
modalities list\[Modality\] | None \[\] Output modalities to request from the model. For OpenAI audio models, pass \["text", "audio"\]. Vertex AI / Gemini translates these to generationConfig.responseModalities (uppercase).
extra_body dict\[str, Any\] | None None Provider-specific extra parameters merged into the request body. Use for guardrails, safety settings, grounding config, etc.

Chat completion response from the API.

Field Type Default Description
id str Unique identifier for this response.
object str Always "chat.completion" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not break deserialization.
created int Unix timestamp of response creation.
model str Model used to generate the response.
choices list\[Choice\] \[\] List of completion choices.
usage Usage | None None Token usage statistics.
system_fingerprint str | None None Fingerprint of the system configuration (OpenAI-specific).
service_tier str | None None Service tier used (OpenAI-specific).

A tool the model can invoke (currently, all tools are functions).

Field Type Default Description
tool_type ToolType Tool type (always “function” in OpenAI spec).
function FunctionDefinition Function definition with name, description, and JSON schema parameters.

A single completion choice.

Field Type Default Description
index int Index of this choice in the choices array.
message AssistantMessage The assistant’s message response.
finish_reason FinishReason | None None Why the model stopped generating (stop, length, tool_calls, content_filter, etc.).

A per-chunk transformation in the StreamPipeline.

Each middleware receives a typed chunk and returns Ok(Some(chunk)) to pass it through (optionally modified), Ok(None) to drop the chunk, or Err(e) to propagate a stream error.

The trait is object-safe so multiple middleware implementations can be chained inside StreamPipeline.

Process a single chunk.

  • Ok(Some(chunk)) — emit (possibly transformed) chunk.
  • Ok(None) — drop this chunk silently.
  • Err(e) — propagate as a stream error.

Signature:

def process(self, chunk: ChatCompletionChunk) -> ChatCompletionChunk | None

Example:

result = instance.process(ChatCompletionChunk())

Parameters:

Name Type Required Description
chunk ChatCompletionChunk Yes The chat completion chunk

Returns: ChatCompletionChunk | None

Errors: Raises LiterLlmError.


Request to create a batch job.

Field Type Default Description
input_file_id str ID of the uploaded input file (JSONL format).
endpoint str API endpoint (e.g., "/v1/chat/completions").
completion_window str Completion window (e.g., "24h").
metadata dict\[str, Any\] | None None Optional metadata to attach to the batch.

Request to upload a file.

Field Type Default Description
file str Base64-encoded file data.
purpose FilePurpose FilePurpose.ASSISTANTS Purpose for the file.
filename str | None None Optional filename to associate with the upload.

Request to create images from a text prompt.

Field Type Default Description
prompt str Text description of the image to generate.
model str | None None Model ID (e.g., "dall-e-3"). Optional; API may use default if unset.
n int | None None Number of images to generate. Defaults to 1.
size str | None None Image size (e.g., "1024x1024", "1792x1024").
quality str | None None Image quality: "standard" or "hd".
style str | None None Style: "natural" or "vivid" (DALL-E 3 only).
response_format str | None None Response format: "url" or "b64_json".
user str | None None User identifier for request tracking.

Request to create a structured response.

Field Type Default Description
model str Model ID.
input dict\[str, Any\] Input data to process (e.g., a document to extract from).
instructions str | None None Instructions for processing the input.
tools list\[ResponseTool\] | None \[\] Available tools the model can use.
temperature float | None None Sampling temperature in \[0.0, 2.0\]. Defaults to 1.0.
max_output_tokens int | None None Maximum output tokens.
metadata dict\[str, Any\] | None None Optional metadata.
stream bool | None None Whether to stream the response. Managed by the client layer — do not set directly.

Request to generate speech audio from text.

Field Type Default Description
model str Model ID (e.g., "tts-1", "tts-1-hd").
input str Text to synthesize into speech.
voice str Voice name (e.g., "alloy", "echo", "fable", "onyx", "nova", "shimmer").
response_format str | None None Audio format (e.g., "mp3", "opus", "aac", "flac", "wav", "pcm").
speed float | None None Playback speed in \[0.25, 4.0\]. Defaults to 1.0.

Request to transcribe audio into text.

Field Type Default Description
model str Model ID (e.g., "whisper-1").
file str Base64-encoded audio file data.
language str | None None Language ISO-639-1 code (e.g., "en", "fr", "de"). Optional; model auto-detects.
prompt str | None None Optional text to guide the model (improves accuracy for domain-specific terms).
response_format str | None None Output format (e.g., "json", "text", "vtt", "srt", "verbose_json").
temperature float | None None Sampling temperature in \[0.0, 1.0\]. Higher increases variability. Defaults to 0.

Configuration for registering a custom LLM provider at runtime.

Field Type Default Description
name str Unique name for this provider (e.g., “my-provider”).
base_url str Base URL for the provider’s API (e.g., <https://api.my-provider.com/v1>).
auth_header AuthHeaderFormat Authentication header format.
model_prefixes list\[str\] Model name prefixes that route to this provider (e.g., \["my-"\]).

Result of decoding a data: URL — MIME type and the decoded byte payload.

Named struct (rather than a tuple) so polyglot bindings can extract decode_data_url with a typed return rather than a sanitized scalar.

Field Type Default Description
mime str MIME type extracted from the URL prefix (verbatim, not normalised).
data bytes Decoded base64 payload.

Default client implementation backed by reqwest.

Sends requests to 165 LLM providers with automatic provider detection and per-request routing. The provider is resolved at construction time from model_hint (or defaults to OpenAI), but individual requests can override the provider via model name prefix (e.g. "anthropic/claude-3-5-sonnet" routes to Anthropic regardless of construction-time setting).

When the model prefix does not match any known provider, the construction-time provider is used as the fallback. This enables seamless migration between providers by changing only the model name.

The provider is stored behind an Arc so it can be shared cheaply into async closures and streaming tasks. Pre-computed auth headers and extra headers are cached at construction to avoid redundant encoding on every request.

Signature:

def fetch_batch_for_polling(self, batch_id: str) -> BatchObject

Example:

result = instance.fetch_batch_for_polling("value")

Parameters:

Name Type Required Description
batch_id str Yes The batch id

Returns: BatchObject

Errors: Raises LiterLlmError.

Poll a batch until it reaches a terminal status (Completed, Failed, Expired, Cancelled).

Uses exponential backoff with configurable initial interval, maximum interval, and backoff multiplier. Optionally supports a timeout that aborts polling if exceeded.

Errors:

Returns BatchWaitError.Failed if the batch reaches a failure terminal status. Returns BatchWaitError.Timeout if the configured timeout is exceeded. Returns BatchWaitError.Client for underlying client errors.

Signature:

def wait_for_batch(self, batch_id: str, config: WaitForBatchConfig) -> BatchObject

Example:

result = instance.wait_for_batch("value", WaitForBatchConfig())

Parameters:

Name Type Required Description
batch_id str Yes The batch id
config WaitForBatchConfig Yes The configuration options

Returns: BatchObject

Errors: Raises BatchWaitError.


Response from a delete operation.

Field Type Default Description
id str ID of the deleted resource.
object str Object type.
deleted bool Confirmation that the resource was deleted.

Developer message (system-like message for Claude models).

Field Type Default Description
content str Developer-specific instructions or context.
name str | None None Optional name for the developer message source.

PDF/document content part for vision-capable models.

Field Type Default Description
data str Base64-encoded document data or URL.
media_type str MIME type (e.g., “application/pdf”, “text/csv”).

A single embedding vector.

Field Type Default Description
object str Always "embedding" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not break deserialization.
embedding list\[float\] The embedding vector. Providers may return this as a JSON float array or, when encoding_format: "base64" was requested, as a base64 string of little-endian f32 bytes. Base64 responses are decoded on read; this field always serializes back out as a JSON float array.
index int Index in the batch (corresponds to input order).

Embedding request.

Field Type Default Description
model str Model ID (e.g., "text-embedding-3-small").
input EmbeddingInput EmbeddingInput.SINGLE Text or texts to embed.
encoding_format EmbeddingFormat | None None Output format: float (native) or base64.
dimensions int | None None Requested embedding dimensions (if supported by the model).
user str | None None User identifier for request tracking.

Embedding response.

Field Type Default Description
object str Always "list" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not break deserialization.
data list\[EmbeddingObject\] List of embeddings.
model str Model used to generate embeddings.
usage Usage | None /* serde(default) */ Token usage (input tokens only; embeddings have zero output tokens).

Query parameters for listing files.

Field Type Default Description
purpose str | None None Filter by file purpose (e.g., "batch", "fine-tune").
limit int | None None Maximum number of results to return. Defaults to 20.
after str | None None Pagination cursor: return results after this file ID.

Response from listing files.

Field Type Default Description
object str Object type (always "list").
data list\[FileObject\] \[\] List of file objects.
has_more bool | None None Whether more results are available.

An uploaded file object.

Field Type Default Description
id str Unique file ID.
object str Object type (always "file").
bytes int File size in bytes.
created_at int Unix timestamp of file creation.
filename str Filename.
purpose str File purpose.
status str | None None Processing status (e.g., "uploaded", "processed").

Function call details.

Field Type Default Description
name str Function name.
arguments str Arguments as a JSON string (parse with serde_json.from_str).

Function definition exposed to the model.

Field Type Default Description
name str Name of the function. Required and must be alphanumeric + underscores.
description str | None /* serde(default) */ Human-readable description explaining what the function does.
parameters dict\[str, Any\] | None /* serde(default) */ JSON Schema defining the function’s parameters.
strict bool | None /* serde(default) */ If true, enforce strict JSON schema validation for arguments.

Deprecated legacy function-role message body.

Field Type Default Description
content str The extracted text content
name str The name

Abstraction over a health probe strategy.

Implementors issue a lightweight probe against upstream (typically a provider base URL or named identifier) and report HealthStatus.

Probe upstream and return its current HealthStatus.

The parameter is taken by value (String) so that implementations can move it into the returned future without a clone, making the 'static + Send bound on the future trivially satisfiable.

Signature:

def check(self, upstream: str) -> HealthStatus

Example:

result = instance.check("value")

Parameters:

Name Type Required Description
upstream str Yes The upstream

Returns: HealthStatus


A single generated image, returned as either a URL or base64 data.

Field Type Default Description
url str | None None Image URL (if response_format was “url”).
b64_json str | None None Base64-encoded image data (if response_format was “b64_json”).
revised_prompt str | None None The final prompt used to generate the image (DALL-E 3).

An image URL reference with optional detail level for processing.

Field Type Default Description
url str URL of the image (data URI or HTTP/HTTPS URL).
detail ImageDetail | None None Detail level: low (512x512), high (2x2 tiles), or auto (model-selected).

Response containing generated images.

Field Type Default Description
created int Unix timestamp of image creation.
data list\[Image\] \[\] List of generated images.

An intent prototype: (intent_name, prototype_embedding, target_model_id).

Field Type Default Description
name str Human-readable name for the intent (used in logs/metrics).
embedding list\[float\] Pre-computed embedding vector for this intent.
model str Model to route to when this intent is detected.

JSON Schema specification for constrained output.

Field Type Default Description
name str Name of the schema (must be unique in the request).
description str | None None Description of what the schema represents.
schema dict\[str, Any\] JSON Schema object defining the output structure.
strict bool | None None If true, enforce strict schema validation.

Budget enforcement configuration.

Field Type Default Description
global_limit float | None None Global spend limit in USD.
model_limits dict\[str, float\] | None {} Per-model spend limits in USD, keyed by model name.
enforcement str | None None Enforcement mode: "hard" (reject over-budget requests) or "soft" (log only).

Response cache configuration.

Field Type Default Description
max_entries int | None None Maximum number of cached entries.
ttl_seconds int | None None Cache entry time-to-live, in seconds.
backend str | None None Cache backend name (e.g. "memory", or an opendal scheme).
backend_config dict\[str, str\] | None {} Backend-specific configuration key/value pairs.

Canonical configuration for an LLM client.

All fields except model are optional so that partially-specified configs (e.g. from environment-driven defaults) round-trip cleanly. Convert to a runtime client configuration via LlmConfig.into_client_builder.

temperature and max_tokens are request-time parameters rather than client-level settings; they are carried on this struct for callers to read when building individual requests, and are intentionally not mapped by LlmConfig.into_client_builder.

Field Type Default Description
model str Model identifier (e.g. "gpt-4o", "bedrock/anthropic.claude-3-sonnet-20240229-v1:0").
api_key str | None None API key for authentication.
base_url str | None None Override base URL. When set, all requests go here and provider auto-detection is skipped.
timeout_secs int | None None Request timeout, in seconds.
max_retries int | None None Maximum number of retries on 429 / 5xx responses.
temperature float | None None Sampling temperature for requests built from this config.
max_tokens int | None None Maximum number of tokens to generate for requests built from this config.
load_env bool | None None Automatically load the API key from the provider’s environment variable when no explicit key is provided (default: True).
headers dict\[str, str\] | None {} Extra headers sent on every request.
providers list\[LlmProviderConfig\] | None \[\] Custom provider configurations, in addition to the built-in providers.
cache LlmCacheConfig | None None Response cache configuration.
budget LlmBudgetConfig | None None Budget enforcement configuration.
rate_limit LlmRateLimitConfig | None None Per-model rate limiting configuration.
cost_tracking bool | None None Enable per-request cost tracking.
tracing bool | None None Enable OpenTelemetry-compatible tracing spans.
cooldown_secs int | None None Cooldown duration after transient errors, in seconds.
health_check_secs int | None None Background health check interval, in seconds.
bedrock BedrockConfig | None None AWS Bedrock configuration (region, credentials, cross-region routing).

Get the custom provider configurations from this config.

Signature:

def providers(self) -> list[LlmProviderConfig]

Example:

result = instance.providers()

Returns: list[LlmProviderConfig]


A custom provider configuration entry.

Field Type Default Description
name str Provider name, used to key model prefix matching.
base_url str Base URL for the provider’s OpenAI-compatible API.
auth_header str | None None Header name used to carry the API key (defaults to Authorization when unset).
model_prefixes list\[str\] \[\] Model name prefixes routed to this provider (e.g. \["my-provider/"\]).

Per-model rate limiting configuration.

Field Type Default Description
rpm int | None None Requests per minute limit.
tpm int | None None Tokens per minute limit.
window_seconds int | None None Rate limit window, in seconds.

Public, FFI-friendly snapshot of a model’s pricing and capability metadata, projected from ModelPricing.

Unlike ModelPricing (which is excluded from binding generation), ModelInfo is an owned plain-data DTO safe to hand across the FFI boundary — see model_info.

Field Type Default Description
input_cost_per_token float Cost in USD per input (prompt) token.
output_cost_per_token float Cost in USD per output (completion) token.
cache_read_input_token_cost float | None None Cost in USD per cached input token (cache hit / read).
cache_creation_input_token_cost float | None None Cost in USD per token written to the prompt cache.
input_cost_per_audio_token float | None None Cost in USD per input audio token.
output_cost_per_audio_token float | None None Cost in USD per output audio token.
output_cost_per_reasoning_token float | None None Cost in USD per reasoning (extended-thinking) output token.
max_tokens int | None None Total context window size in tokens (input + output).
max_input_tokens int | None None Maximum input (prompt) tokens accepted.
max_output_tokens int | None None Maximum output (completion) tokens the model can generate.
mode str | None None Best-effort operating mode, e.g. "chat", "embedding".
supports_vision bool | None None The model accepts image input.
supports_function_calling bool | None None The model supports tool / function calling.
supports_reasoning bool | None None The model supports extended-thinking / reasoning tokens.
supports_structured_output bool | None None The model supports JSON-mode or response_format structured output.
supports_audio_input bool | None None The model accepts audio input.
supports_audio_output bool | None None The model can generate audio output.
supports_prompt_caching bool | None None The model supports prompt caching.
tiers list\[ModelTier\] \[\] Context-tiered pricing overrides, sorted by ascending min_context_tokens. Empty when the model has flat pricing.

A model available from the API.

Field Type Default Description
id str Model ID (e.g., "gpt-4o", "claude-3-5-sonnet").
object str Always "model" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not break deserialization. Defaults to empty when a provider omits the field.
created int Unix timestamp of model creation (or release date). Defaults to 0 when a provider omits it — DeepSeek and some other OpenAI-compatible providers do not return created from /v1/models.
owned_by str Organization or entity that owns the model. Defaults to empty when a provider omits the field.

Public, FFI-friendly snapshot of a single context-window pricing tier, projected from PricingTier.

Field Type Default Description
min_context_tokens int The tier applies when the prompt/context token count is at least this value.
input_cost_per_token float Cost in USD per input (prompt) token within this tier.
output_cost_per_token float Cost in USD per output (completion) token within this tier.
cache_read_input_token_cost float | None None Cost in USD per cached input token within this tier.
cache_creation_input_token_cost float | None None Cost in USD per cache-write token within this tier.
input_cost_per_audio_token float | None None Cost in USD per input audio token within this tier.
output_cost_per_audio_token float | None None Cost in USD per output audio token within this tier.
output_cost_per_reasoning_token float | None None Cost in USD per reasoning output token within this tier.

Response listing available models.

Field Type Default Description
object str Always "list" from OpenAI-compatible APIs. Stored as a plain String so non-standard provider values do not break deserialization. Defaults to empty when a provider omits the field.
data list\[ModelObject\] \[\] List of available models.

Boolean flags for each moderation category.

Field Type Default Description
sexual bool Sexual content.
hate bool Hate speech.
harassment bool Harassment.
self_harm bool Self-harm content.
sexual_minors bool Sexual content involving minors.
hate_threatening bool Hate speech that threatens violence.
violence_graphic bool Graphic violence.
self_harm_intent bool Intent to self-harm.
self_harm_instructions bool Instructions for self-harm.
harassment_threatening bool Harassment that threatens violence.
violence bool Non-graphic violence.

Confidence scores for each moderation category.

Field Type Default Description
sexual float Sexual content score.
hate float Hate speech score.
harassment float Harassment score.
self_harm float Self-harm content score.
sexual_minors float Sexual content involving minors score.
hate_threatening float Hate speech that threatens violence score.
violence_graphic float Graphic violence score.
self_harm_intent float Intent to self-harm score.
self_harm_instructions float Instructions for self-harm score.
harassment_threatening float Harassment that threatens violence score.
violence float Non-graphic violence score.

Request to classify content for policy violations.

Field Type Default Description
input ModerationInput ModerationInput.SINGLE Text or texts to check.
model str | None None Model ID (e.g., "text-moderation-latest"). Optional; API uses default if unset.

Response from the moderation endpoint.

Field Type Default Description
id str Unique identifier for this moderation request.
model str Model used for classification.
results list\[ModerationResult\] Results for each input string.

A single moderation classification result.

Field Type Default Description
flagged bool True if any category was flagged.
categories ModerationCategories Boolean flags for each moderation category.
category_scores ModerationCategoryScores Confidence scores for each category.

An image extracted from an OCR page.

Field Type Default Description
id str Unique image identifier within the document.
image_base64 str | None /* serde(default) */ Base64-encoded image data (if include_image_base64 was true).

A single page of OCR output.

Field Type Default Description
index int Page index (0-based).
markdown str Extracted page content as Markdown.
images list\[OcrImage\] | None /* serde(default) */ Embedded images extracted from the page (if include_image_base64 was true).
dimensions PageDimensions | None /* serde(default) */ Page dimensions in pixels, if available.

An OCR request.

Field Type Default Description
model str The model/provider to use (e.g. "mistral/mistral-ocr-latest").
document OcrDocument OcrDocument.URL The document to process (URL or base64).
pages list\[int\] | None \[\] Specific pages to process (1-indexed). None means all pages.
include_image_base64 bool | None None Whether to include base64-encoded images of each processed page.

An OCR response.

Field Type Default Description
pages list\[OcrPage\] Extracted pages in order.
model str Model/provider used for OCR.
usage Usage | None /* serde(default) */ Token usage, if reported by the provider.

Page dimensions in pixels.

Field Type Default Description
width int Width in pixels.
height int Height in pixels.

Breakdown of tokens used in the prompt portion of a request.

cached_tokens is included in Usage.prompt_tokens — it is not an additional charge on top of the prompt token count. When pricing supports a cache_read_input_token_cost, the cached portion is billed at the discounted rate and the remainder at the regular input rate.

Field Type Default Description
cached_tokens int Cached tokens present in the prompt. Defaults to 0 when absent.
audio_tokens int Audio input tokens present in the prompt. Defaults to 0 when absent.

Static capability flags for a provider.

Each flag indicates whether the provider’s models generally support that feature. For providers that aggregate many underlying models (e.g. Bedrock, OpenRouter, vLLM) the flags reflect the superset of available model capabilities — a flag being True means at least one model supports the feature, not every model.

All flags default to False so that newly added providers are safe.

Access via the crate-level capabilities function:

Field Type Default Description
vision bool The provider accepts image input in chat messages.
reasoning bool The provider supports extended-thinking / reasoning tokens.
structured_output bool The provider supports JSON-mode or response_format structured output.
function_calling bool The provider supports tool / function calling.
audio_in bool The provider accepts audio as input.
audio_out bool The provider can generate audio / TTS output.
video_in bool The provider accepts video as input.

Static configuration for a single provider entry in providers.json.

This struct deliberately does not include capability flags or streaming format, which are accessed via the capabilities function.

Field Type Default Description
name str Provider identifier (matches the entry key in providers.json).
display_name str | None None Human-readable provider name shown in UIs.
base_url str | None None Base URL used as the default for this provider’s HTTP client.
auth AuthConfig | None None Authentication scheme metadata (auth type + env var holding the key).
endpoints list\[str\] | None None Supported endpoint kinds (e.g. chat, embeddings).
model_prefixes list\[str\] | None None Model-name prefixes claimed by this provider (e.g. \["gpt-", "o1-"\]).
param_mappings dict\[str, str\] | None None Parameter key renaming for this provider. Each entry maps an OpenAI-spec field name (e.g. "max_completion_tokens") to the name this provider expects (e.g. "max_tokens"). Applied automatically by ConfigDrivenProvider.transform_request.

Configuration for per-model rate limits.

Field Type Default Description
rpm int | None None Maximum requests per window. None means unlimited.
tpm int | None None Maximum tokens per window. None means unlimited.
window float 60000ms Fixed window duration (defaults to 60 s).

Signature:

@staticmethod
def default() -> RateLimitConfig

Example:

result = RateLimitConfig.default()

Returns: RateLimitConfig


Request to rerank documents by relevance to a query.

Field Type Default Description
model str Model ID (e.g., "cohere/rerank-english-v3.0").
query str The search query.
documents list\[RerankDocument\] \[\] Documents to rerank.
top_n int | None None Return only the top N results. Optional.
return_documents bool | None None Include the document content in results. Defaults to false.

Response from the rerank endpoint.

Field Type Default Description
id str | None None Unique identifier for this rerank request.
results list\[RerankResult\] Reranked documents in order of relevance.
meta dict\[str, Any\] | None /* serde(default) */ Optional metadata about the reranking operation.

A single reranked document with its relevance score.

Field Type Default Description
index int Original document index in the input list.
relevance_score float Relevance score in \[0, 1\]. Higher indicates more relevant.
document RerankResultDocument | None /* serde(default) */ Original document content (if return_documents was true).

The text content of a reranked document, returned when return_documents is true.

Field Type Default Description
text str Document text.

Response from a structured response request.

Field Type Default Description
id str Unique response ID.
object str Object type (e.g., "response").
created_at int Unix timestamp of response creation.
model str Model used to generate the response.
status str Status (e.g., "succeeded", "failed").
output list\[ResponseOutputItem\] \[\] Output items from the response.
usage ResponseUsage | None None Token usage.
error dict\[str, Any\] | None None Error details (if status is “failed”).

A single output item from the response.

Field Type Default Description
item_type str Output type (e.g., "text", "object", "error").
content dict\[str, Any\] Output content (flattened into the object).

A tool available for the response request.

Field Type Default Description
tool_type str Tool type (e.g., “extractor”, “search”).
config dict\[str, Any\] Tool configuration (flattened into the object).

Token usage for a response.

Field Type Default Description
input_tokens int Input tokens used.
output_tokens int Output tokens used.
total_tokens int Total tokens used.

A search request.

Field Type Default Description
model str The model/provider to use (e.g. "brave/web-search", "tavily/search").
query str The search query string.
max_results int | None None Maximum number of results to return.
search_domain_filter list\[str\] | None \[\] Domain filter — restrict results to specific domains.
country str | None None Country code for localized results (ISO 3166-1 alpha-2, e.g., "US", "FR").

A search response.

Field Type Default Description
results list\[SearchResult\] List of search results.
model str Model/provider that performed the search.

An individual search result.

Field Type Default Description
title str Result title.
url str Result URL.
snippet str Text snippet or excerpt from the page.
date str | None /* serde(default) */ Publication or last-updated date, if available.

The value broadcast from a singleflight leader to all followers.

The error value is shared so every follower receives the same upstream failure without cloning the underlying error.


Name of the specific function to invoke.

Field Type Default Description
name str Function name.

Directive to call a specific tool.

Field Type Default Description
choice_type ToolType ToolType.FUNCTION Tool type (always “function”).
function SpecificFunction The specific function to invoke.

A streaming choice with incremental delta.

Field Type Default Description
index int Index of this choice in the choices array.
delta StreamDelta Incremental update to the message (content, tool calls, etc.).
finish_reason FinishReason | None None Why the stream ended (present only in final chunk).

Incremental delta in a stream chunk.

Field Type Default Description
role str | None None Role (typically present only in the first chunk).
content str | None None Partial content chunk (e.g., a few words of the response).
tool_calls list\[StreamToolCall\] | None \[\] Partial tool calls being streamed.
function_call StreamFunctionCall | None None Deprecated legacy function_call delta; retained for API compatibility.
refusal str | None None Partial refusal message.
reasoning_content str | None None Partial reasoning/thinking tokens (OpenAI-compatible extension used by DeepSeek R1, Qwen, etc.).

Partial function call details in a stream.

Field Type Default Description
name str | None None Function name (typically in the first chunk).
arguments str | None None Partial JSON arguments chunk.

Options for streaming responses.

Field Type Default Description
include_usage bool | None None If true, include token usage in the final stream chunk.

A streaming tool call being built incrementally.

Field Type Default Description
index int Index of this tool call in the tool_calls array.
id str | None None Tool call ID (typically in the first chunk for this call).
call_type ToolType | None None Tool type (typically “function”).
function StreamFunctionCall | None None Partial function name and arguments.

System message guiding model behavior for the entire conversation.

Field Type Default Description
content UserContent UserContent.TEXT Instructions or context that apply throughout the conversation. Accepts either a plain text string or an array of content parts, mirroring UserContent so that Message.system_with_parts works.
name str | None None Optional name for the system message source.

A tool call the model wants to execute.

Field Type Default Description
id str Unique ID for this call, used to reference in tool result messages.
call_type ToolType Tool type (always “function”).
function FunctionCall Function name and arguments.

Tool execution result returned to the model.

Field Type Default Description
content UserContent UserContent.TEXT Result of the tool execution as plain text or an array of content parts (text, images, documents, audio), mirroring UserMessage.content. #\[serde(untagged)\] on UserContent means a bare JSON string still deserialises into Text, so tool results persisted before this field carried structured content continue to round-trip.
tool_call_id str ID of the tool call this result responds to.
name str | None None Optional tool/function name.

Response from a transcription request.

Field Type Default Description
text str The transcribed text.
language str | None None Detected language (ISO-639-1 code).
duration float | None None Total audio duration in seconds.
segments list\[TranscriptionSegment\] | None \[\] Detailed segment-level transcription (if response_format is “verbose_json”).

A segment of transcribed audio with timing information.

Field Type Default Description
id int Segment index (0-based).
start float Start time in seconds.
end float End time in seconds.
text str Transcribed text for this segment.

Token-usage accounting returned by the provider on each completion / embedding call.

Field Type Default Description
prompt_tokens int Prompt tokens used. Defaults to 0 when absent (some providers omit this).
completion_tokens int Completion tokens used. Defaults to 0 when absent (e.g. embedding responses).
total_tokens int Total tokens used. Defaults to 0 when absent (some providers omit this).
prompt_tokens_details PromptTokensDetails | None None Breakdown of tokens used in the prompt, including cached tokens served at the provider’s discounted cache-read rate. Absent when the provider does not return prompt-token details.

User message in the conversation.

Field Type Default Description
content UserContent UserContent.TEXT Message content as plain text or array of content parts (text, images, documents, audio).
name str | None None Optional name for the user.

Configuration for polling a batch until terminal status.

All time values are in seconds as f64 so the struct bridges across FFI boundaries without requiring a Duration shim.

Field Type Default Description
initial_interval_secs float 5 Initial interval between polls, in seconds.
max_interval_secs float 60 Maximum interval between polls (backoff plateau), in seconds.
backoff_multiplier float 1.5 Exponential backoff multiplier (e.g., 1.5 increases delay by 50% each poll).
timeout_secs float | None None Optional timeout in seconds — polling fails if this duration is exceeded.

Signature:

@staticmethod
def default() -> WaitForBatchConfig

Example:

result = WaitForBatchConfig.default()

Returns: WaitForBatchConfig


A chat message in a conversation.

Value Description
SYSTEM System — Fields: 0: SystemMessage
USER User — Fields: 0: UserMessage
ASSISTANT Assistant — Fields: 0: AssistantMessage
TOOL Tool — Fields: 0: ToolMessage
DEVELOPER Developer — Fields: 0: DeveloperMessage
FUNCTION Deprecated legacy function-role message; retained for API compatibility. — Fields: 0: FunctionMessage

User message content as either plain text or a list of multimodal parts.

Value Description
TEXT Plain text content. — Fields: 0: str
PARTS Array of content parts (text, images, documents, audio). — Fields: 0: list\[ContentPart\]

A single content part in a user message — text, image, document, or audio.

Value Description
TEXT Plain text. — Fields: text: str
IMAGE_URL Image identified by URL (with optional detail level). — Fields: image_url: ImageUrl
DOCUMENT Document file (PDF, CSV, etc.) as base64 or URL. — Fields: document: DocumentContent
INPUT_AUDIO Audio input as base64. — Fields: input_audio: AudioContent

Image detail level controlling token cost and processing.

Value Description
LOW Low detail: scales image to 512x512, uses fewer tokens.
HIGH High detail: processes up to 2x2 grid of tiles, higher token cost.
AUTO Auto: model chooses low or high based on image dimensions.

Content shape for assistant messages.

#[serde(untagged)] means providers returning a plain scalar string for the content field still deserialise correctly into AssistantContent.Text(_). Providers returning an array of typed parts (e.g. after an image-generation or audio-synthesis request) deserialise into AssistantContent.Parts(_).

Value Description
TEXT Plain text response (the common case for text-only models). — Fields: 0: str
PARTS Structured parts — text, refusals, output images, output audio. — Fields: 0: list\[AssistantPart\]

One part of a structured assistant response.

#[serde(tag = "type", rename_all = "snake_case")] matches OpenAI’s parts-spec discriminator ("type": "text", "type": "output_image", …).

Value Description
TEXT A text segment of the response. — Fields: text: str
REFUSAL A refusal — the model declined to respond. — Fields: refusal: str
OUTPUT_IMAGE An image produced by the model (e.g. gpt-image-1, Gemini Imagen). — Fields: image_url: ImageUrl
OUTPUT_AUDIO Audio produced by the model (e.g. gpt-4o-audio-preview). — Fields: audio: AudioContent

The type discriminator for tool/tool-call objects.

Per the OpenAI spec this is always "function". Using an enum enforces that constraint at the type level and rejects any other value on deserialization.

Value Description
FUNCTION Function

Tool usage mode or a specific tool to call.

Value Description
MODE Predefined mode: auto, required, or none. — Fields: 0: ToolChoiceMode
SPECIFIC Force a specific tool to be called. — Fields: 0: SpecificToolChoice

Tool choice mode.

Value Description
AUTO Model may or may not call tools; default behavior.
REQUIRED Model must call at least one tool.
NONE Model must not call any tools.

Wire format for the chat completions response_format field.

  • OpenAI (and OpenAI-compatible providers): emitted verbatim as {"type": "json_schema", "json_schema": {...}} per the chat-completions spec.

  • Gemini / Vertex AI: translated to generationConfig.responseMimeType = "application/json" and generationConfig.responseSchema = <schema>. The name, description, and strict fields are dropped — Gemini’s structured-output API does not consume them.

  • Anthropic: no native JSON mode. A system instruction is prepended asking the model to respond with valid JSON. strict is advisory only; callers should still validate the returned JSON if the schema is load-bearing.

Value Description
TEXT Plain text output (default).
JSON_OBJECT Output must be valid JSON object (no schema validation).
JSON_SCHEMA Output must conform to the specified JSON schema. — Fields: json_schema: JsonSchemaFormat

Stop sequence(s) that cause the model to stop generating.

Value Description
SINGLE Single stop sequence. — Fields: 0: str
MULTIPLE Multiple stop sequences. — Fields: 0: list\[str\]

Output modality requested from the model.

Passed as modalities: ["text", "audio"] (OpenAI) or translated to generationConfig.responseModalities (Gemini / Vertex AI).

Value Description
TEXT Text output (the default for all providers).
AUDIO Audio / speech output.
IMAGE Image output (Gemini Imagen, gpt-image-1).

Why a choice stopped generating tokens.

Value Description
STOP Stop
LENGTH Length
TOOL_CALLS Tool calls
CONTENT_FILTER Content filter
FUNCTION_CALL Deprecated legacy finish reason; retained for API compatibility.
OTHER Catch-all for unknown finish reasons returned by non-OpenAI providers. Note: this intentionally does not carry the original string (e.g. Other(String)). Using #\[serde(other)\] requires a unit variant, and switching to #\[serde(untagged)\] would change deserialization semantics for all variants. The original value can be recovered by inspecting the raw JSON if needed.

Controls how much reasoning effort the model should use.

Value Description
LOW Low
MEDIUM Medium
HIGH High
MINIMAL Minimal
MAX Max

The format in which the embedding vectors are returned.

Value Description
FLOAT 32-bit floating-point numbers (default).
BASE64 Base64-encoded string representation of the floats.

Text or texts to embed.

Value Description
SINGLE Single text string. — Fields: 0: str
MULTIPLE Multiple text strings (batch embedding). — Fields: 0: list\[str\]

Input to the moderation endpoint — a single string or multiple strings.

Value Description
SINGLE Single text string. — Fields: 0: str
MULTIPLE Multiple text strings (batch moderation). — Fields: 0: list\[str\]

A document to be reranked — either a plain string or an object with a text field.

Value Description
TEXT Plain text document content. — Fields: 0: str
OBJECT Document with explicit text field (may include metadata). — Fields: text: str

Document input for OCR — either a URL or inline base64 data.

Value Description
URL A publicly accessible document URL. — Fields: url: str
BASE64 Inline base64-encoded document data. — Fields: data: str, media_type: str

Purpose of an uploaded file.

Value Description
ASSISTANTS File for use with Assistants API.
BATCH File for batch processing.
FINE_TUNE File for fine-tuning.
VISION File for vision/image tasks.

Status of a batch job.

Value Description
VALIDATING Validating the input file.
FAILED Job failed.
IN_PROGRESS Job is running.
FINALIZING Finalizing results.
COMPLETED Job completed successfully.
EXPIRED Job expired before completion.
CANCELLING Job is being cancelled.
CANCELLED Job has been cancelled.

How the API key is sent in the HTTP request.

Value Description
BEARER Bearer token: Authorization: Bearer <key>
API_KEY Custom header: e.g., X-Api-Key: <key> — Fields: 0: str
NONE No authentication required.

The streaming wire format a provider uses for its response stream.

Most providers use standard Server-Sent Events (SSE). AWS Bedrock uses a proprietary binary EventStream framing.

Deserialized from the streaming_format JSON field via serde.

Value Description
SSE Standard Server-Sent Events (text/event-stream).
AWS_EVENT_STREAM AWS EventStream binary framing (application/vnd.amazon.eventstream).

Auth scheme used by a provider.

Value Description
BEARER Standard Authorization: Bearer <key> header.
API_KEY x-api-key: <key> header (also handles "header" and "x-api-key" aliases).
NONE No authentication header required.
UNKNOWN Unrecognised auth scheme — falls back to bearer.

How budget limits are enforced.

Value Description
HARD Reject requests that would exceed the budget with LiterLlmError.BudgetExceeded.
SOFT Allow requests through but emit a tracing.warn! when the budget is exceeded.

Storage backend for the response cache.

Value Description
MEMORY In-memory LRU cache (default). No external dependencies.
OPEN_DAL OpenDAL-backed storage. Supports 40+ backends (S3, Redis, GCS, local FS, etc.). — Fields: scheme: str, config: dict\[str, str\]

Observable state of a circuit breaker.

Value Description
CLOSED Requests flow through normally.
OPEN All requests are rejected; the circuit is waiting for the backoff to elapse.
HALF_OPEN One probe request is allowed through to test service health.

The result of a single health probe.

Value Description
HEALTHY The probe succeeded; the upstream is reachable.
UNHEALTHY The probe failed; the upstream may be down.

Result of a refresh_catalog call.

Value Description
DISABLED config.enabled was False; no network, filesystem, or overlay activity occurred.
FROM_CACHE The on-disk cache was fresh (age < ttl_seconds); the overlay was installed from the cached file without a network request.
FETCHED The catalog was fetched over the network, the cache file was (best-effort) refreshed, and the overlay was installed from the fetched catalog.

All errors that can occur when using liter-llm.

Base class: LiterLlmError(Exception)

Exception Description
Authentication(LiterLlmError) status preserves the exact HTTP status code received (401 or 403).
RateLimited(LiterLlmError) rate limited: {message}
BadRequest(LiterLlmError) status preserves the exact HTTP status code received (400, 405, 413, 422, …).
ContextWindowExceeded(LiterLlmError) context window exceeded: {message}
ContentPolicy(LiterLlmError) content policy violation: {message}
NotFound(LiterLlmError) not found: {message}
ServerError(LiterLlmError) status preserves the exact HTTP status code received (500, or other 5xx not covered by ServiceUnavailable).
ServiceUnavailable(LiterLlmError) status preserves the exact HTTP status code received (502, 503, or 504).
Timeout(LiterLlmError) request timeout
Streaming(LiterLlmError) A catch-all for errors that occur during streaming response processing. This variant covers multiple sub-conditions including UTF-8 decoding failures, CRC/checksum mismatches (AWS EventStream), JSON parse errors in individual SSE chunks, and buffer overflow conditions. The message field contains a human-readable description of the specific failure.
EndpointNotSupported(LiterLlmError) provider {provider} does not support {endpoint}
InvalidHeader(LiterLlmError) invalid header {name:?}: {reason}
Serialization(LiterLlmError) serialization error: {0}
BudgetExceeded(LiterLlmError) budget exceeded: {message}
HookRejected(LiterLlmError) hook rejected: {message}
InternalError(LiterLlmError) An internal logic error (e.g. unexpected Tower response variant). This should never surface in normal operation — if it does, it indicates a bug in the library.
OutboundForbidden(LiterLlmError) An outbound request was blocked by the active OutboundPolicy. Returned when register_custom_provider is called with a base_url that violates the policy (e.g. a private-range IP under DenyPrivate), or when the per-connection DNS resolver detects a forbidden address at connect time.
IdempotencyConflict(LiterLlmError) A different request body was submitted for an existing Idempotency-Key. Per the OpenAI Idempotency-Key convention, once a key is used with a particular request body, subsequent requests using the same key must carry an identical body. A body mismatch is a hard error (not retryable). HTTP equivalent: 409 Conflict.
IdempotencyInFlight(LiterLlmError) The same Idempotency-Key is already in-flight (another request with the same key is currently being processed). The caller should wait briefly and retry. The response is not yet available, and this request has been short-circuited to avoid running the operation twice. HTTP equivalent: 409 Conflict (retryable after a brief delay).

Errors from refresh_catalog and install_catalog_overlay_from_str.

On every variant, the overlay registry is left untouched: a previously installed overlay (or the embedded catalog, if none was ever installed) remains active. This is the air-gap-safety contract — a failed refresh never degrades pricing/model-info availability.

Base class: CatalogRefreshError(Exception)

Exception Description
Disabled(CatalogRefreshError) Runtime catalog refresh was not enabled. refresh_catalog itself never returns this — it returns Ok(RefreshOutcome.Disabled) instead — but the variant is part of the public error surface for callers that want to treat “disabled” as a hard error.
InsecureUrl(CatalogRefreshError) source_url did not use the https scheme, or failed to parse as a URL at all. There is no host allowlist: the URL is user-configurable for self-hosted catalog mirrors, so only the scheme is enforced.
Fetch(CatalogRefreshError) The network fetch failed, timed out, or returned a non-success status.
Parse(CatalogRefreshError) The fetched or cached catalog JSON failed to parse.
Cache(CatalogRefreshError) A cache file read failed on an otherwise-fresh cache file. Cache write failures are best-effort and never surface as this error (see refresh_catalog).