cubepi.providers

AssistantMessage

class

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Attributes

• role: Literal['assistant']
• content: list[Content | ThinkingContent | ToolCall]
• stop_reason: str
• error_message: str | None
• usage: Usage | None
• timestamp: float | None
• provider_id: str
• model_id: str
• response_id: str | None
• metadata: JsonObject
• run_id: str | None

BaseProvider

class

BaseProvider(self, *, provider_id: str = '')

Concrete base class for built-in cubepi providers.

Built-in providers (Anthropic, OpenAI, OpenAI Responses, Faux) inherit from this class to gain the persistent listener registry used by cubepi.tracing and other observers. User-defined providers should inherit from BaseProvider unless they implement the full Provider protocol themselves.

Concrete subclasses must implement stream() and call _fire_listeners at three points: after the request payload is finalized, for each StreamEvent pushed onto the stream, and exactly once in a finally block after the stream terminates.

Per-call mutators (StreamOptions.on_payload, StreamOptions.on_response) retain their existing single-slot semantics and fire independently of the persistent listener registry below.

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Attributes

• provider_id

Methods

model

model(id: str, *, api: str = '', reasoning: bool = False, context_window: int = 200000, max_tokens: int = 8192, temperature: float = 0.7, cost: ModelCost | None = None, thinking_level_map: dict[str, str | None] | None = None) -> BoundModel

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stream

stream(model: Model, messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None) -> MessageStream

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generate

generate(model: Model, messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None, max_output_tokens: int | None = None, temperature: float | None = None, thinking: ThinkingLevel | None = None, thinking_budgets: ThinkingBudgets | None = None) -> AssistantMessage

Run a single provider call and return the final assistant message.

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subscribe_request

subscribe_request(cb: OnRequestCallback) -> Callable[[], None]

Register a persistent observer for request payloads.

Returns a detach callable that removes this specific subscription.

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subscribe_chunk

subscribe_chunk(cb: OnChunkCallback) -> Callable[[], None]

Register a persistent observer for stream chunks.

Returns a detach callable.

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subscribe_response

subscribe_response(cb: OnResponseBodyCallback) -> Callable[[], None]

Register a persistent observer for assembled responses.

Returns a detach callable.

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BoundModel

class

BoundModel(self, provider: Provider, spec: Model)

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Attributes

• provider: Provider
• spec: Model

Methods

stream

stream(messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None) -> MessageStream

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generate

generate(messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None, max_output_tokens: int | None = None, temperature: float | None = None, thinking: ThinkingLevel | None = None, thinking_budgets: ThinkingBudgets | None = None) -> AssistantMessage

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Content

attribute

Content = TextContent | ImageContent

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ImageContent

class

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Attributes

• type: Literal['image']
• source: str
• media_type: str

Message

attribute

Message = UserMessage | AssistantMessage | ToolResultMessage

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MessageStream

class

MessageStream(self)

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Methods

attach_task

attach_task(task: asyncio.Task) -> None

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push

push(event: StreamEvent) -> None

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set_result

set_result(message: AssistantMessage) -> None

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result

result() -> AssistantMessage

Return the final assistant message.

Blocks not just on the result future, but also on the producer task's completion — the producer's finally block runs _fire_response_listeners (after set_result), so without waiting for the task, callers under asyncio.run teardown could exit before async response listeners have run. Producer exceptions are NOT re-raised here; they were already surfaced via the result future or the stream's error events.

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Model

class

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Attributes

• id: str
• provider_id: str
• api: str
• reasoning: bool
• context_window: int
• max_tokens: int
• temperature: float
• cost: ModelCost | None
• thinking_level_map: dict[str, str | None] | None

ModelCost

class

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Attributes

• input: float
• output: float
• cache_read: float
• cache_write: float

OnChunkCallback

attribute

OnChunkCallback = Callable[['StreamEvent', Model], Awaitable[None] | None]

Persistent observer. Fires for every StreamEvent pushed onto the stream (start, text_delta, thinking_delta, toolcall_delta, done, error, ...). Heavy listeners should early-return on irrelevant event types — this hook fires hot. Return value is ignored.

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OnPayloadCallback

attribute

OnPayloadCallback = Callable[[dict, Model], Awaitable[dict | None] | dict | None]

Optional callback for inspecting/replacing provider payloads before sending. Return a dict to replace the payload, or None to keep unchanged.

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OnRequestCallback

attribute

OnRequestCallback = Callable[[dict, Model], Awaitable[None] | None]

Persistent observer. Fires just before HTTP send, after any per-call StreamOptions.on_payload mutation has been applied. Receives the final wire payload dict and the Model. Return value is ignored.

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OnResponseBodyCallback

attribute

OnResponseBodyCallback = Callable[[dict | None, Model, BaseException | None], Awaitable[None] | None]

Persistent observer. Fires exactly once per stream() call, in a finally block, after the stream terminates.

• body: assembled provider response as a dict (same shape a non-streaming call to the provider would have returned), or None if the stream failed before a response could be assembled.
• exc: the exception that ended the stream (including asyncio.CancelledError), or None on normal completion. Return value is ignored.

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OnResponseCallback

attribute

OnResponseCallback = Callable[['ProviderResponse', Model], Awaitable[None] | None]

Optional callback invoked after an HTTP response is received.

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Provider

class

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Methods

stream

stream(model: Model, messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None) -> MessageStream

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generate

generate(model: Model, messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None, max_output_tokens: int | None = None, temperature: float | None = None, thinking: ThinkingLevel | None = None, thinking_budgets: ThinkingBudgets | None = None) -> AssistantMessage

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ProviderResponse

class

ProviderResponse(self, status: int, headers: dict[str, str] = dict())

HTTP response metadata exposed to on_response callbacks.

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Attributes

• status: int
• headers: dict[str, str]

StreamEvent

class

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Attributes

• type: Literal['start', 'text_start', 'text_delta', 'text_end', 'thinking_start', 'thinking_delta', 'thinking_end', 'toolcall_start', 'toolcall_delta', 'toolcall_end', 'done', 'error']
• content_index: int | None
• delta: str | None
• partial: AssistantMessage | None
• error_message: str | None

StreamOptions

class

Options bag for Provider.stream(), transparent to the agent loop.

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Attributes

• model_config
• thinking: ThinkingLevel
• thinking_budgets: ThinkingBudgets | None
• signal: asyncio.Event | None
• on_payload: OnPayloadCallback | None
• on_response: OnResponseCallback | None

TextContent

class

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Attributes

• type: Literal['text']
• text: str

ThinkingBudgets

class

Token budgets for each thinking level.

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Attributes

• minimal: int
• low: int
• medium: int
• high: int

ThinkingContent

class

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Attributes

• type: Literal['thinking']
• thinking: str

ThinkingLevel

attribute

ThinkingLevel = Literal['off', 'minimal', 'low', 'medium', 'high', 'xhigh']

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ToolCall

class

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Attributes

• type: Literal['tool_call']
• id: str
• name: str
• arguments: JsonObject

ToolDefinition

class

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Attributes

• name: str
• description: str
• parameters: JsonObject

ToolResultMessage

class

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Attributes

• role: Literal['tool_result']
• tool_call_id: str
• tool_name: str
• content: list[Content]
• details: StructuredValue
• is_error: bool
• timestamp: float | None
• metadata: JsonObject
• run_id: str | None

Usage

class

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Attributes

• input_tokens: int
• output_tokens: int
• cache_read_tokens: int
• cache_write_tokens: int

UserMessage

class

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Attributes

• role: Literal['user']
• content: list[Content]
• timestamp: float | None
• metadata: JsonObject
• run_id: str | None

adjust_max_tokens_for_thinking

function

adjust_max_tokens_for_thinking(base_max_tokens: int, model_max_tokens: int, reasoning_level: ThinkingLevel, custom_budgets: ThinkingBudgets | None = None) -> tuple[int, int]

Adjust max_tokens to reserve space for a thinking budget.

Given a base max_tokens (the desired output capacity), increases it to accommodate the thinking budget while respecting the model's hard cap. If the model cap is too small to fit both, the thinking budget is reduced to leave at least min_output_tokens (1024) for output.

Returns

• A (max_tokens, thinking_budget) tuple.

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FauxProvider

class

FauxProvider(self, *, tokens_per_second: float | None = None, token_size_min: int = 3, token_size_max: int = 5, provider_id: str = '')

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Attributes

• call_count
• pending_response_count: int
• prompt_cache: dict[str, str] — Read-only access to the prompt cache for test assertions.

Methods

set_responses

set_responses(responses: list[FauxResponseStep]) -> None

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append_responses

append_responses(responses: list[FauxResponseStep]) -> None

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clear_prompt_cache

clear_prompt_cache() -> None

Clear the prompt cache, useful between test scenarios.

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stream

stream(model: Model, messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None) -> MessageStream

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faux_assistant_message

function

faux_assistant_message(content: str | FauxContentBlock | list[FauxContentBlock], *, stop_reason: str = 'stop', error_message: str | None = None) -> AssistantMessage

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faux_text

function

faux_text(text: str) -> TextContent

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faux_thinking

function

faux_thinking(thinking: str) -> ThinkingContent

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faux_tool_call

function

faux_tool_call(name: str, arguments: dict[str, Any], *, id: str | None = None) -> ToolCall

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DEFAULT_TRIGGER_ERRORS

attribute

DEFAULT_TRIGGER_ERRORS: frozenset[type[ProviderError]] = frozenset({RateLimited, ProviderUnavailable, ContextLengthExceeded})

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FallbackBoundModel

class

FallbackBoundModel(self, chain: tuple[BoundModel, ...], trigger_errors: frozenset[type[ProviderError]] = DEFAULT_TRIGGER_ERRORS, on_failover: Callable[[BoundModel, BoundModel | None, BaseException | str], Awaitable[None] | None] | None = None)

Ordered chain of BoundModels — tries each in turn on retriable errors.

chain[0] is the primary model. On a trigger_errors exception or a first-event error from stream(), the next model in the chain is tried transparently. For generate(), an error AssistantMessage (stop_reason="error") also triggers failover. Mid-stream errors (after the first non-error event) are forwarded as-is.

provider and spec proxy chain[0] so tracing/billing code that reads agent._model.provider / agent._model.spec continues to work unchanged.

Known limitation: Tracer.attach() and Meter.attach() subscribe only to chain[0].provider. Successful fallback calls (chain[1..]) are invisible to provider-level observability (chat spans, token/cost metrics). Tracked as a follow-up: update recorder.py and meter.py to iterate chain and subscribe to every unique BaseProvider.

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Attributes

• chain: tuple[BoundModel, ...]
• trigger_errors: frozenset[type[ProviderError]]
• on_failover: Callable[[BoundModel, BoundModel | None, BaseException | str], Awaitable[None] | None] | None
• provider: Provider
• spec: Model

Methods

stream

stream(messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None) -> MessageStream

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generate

generate(messages: list[Message], *, system_prompt: str = '', tools: list[ToolDefinition] | None = None, options: StreamOptions | None = None, max_output_tokens: int | None = None, temperature: float | None = None, thinking: ThinkingLevel | None = None, thinking_budgets: ThinkingBudgets | None = None) -> AssistantMessage

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THINKING_LEVELS

attribute

THINKING_LEVELS: list[ThinkingLevel] = ['off', 'minimal', 'low', 'medium', 'high', 'xhigh']

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clamp_thinking_level

function

clamp_thinking_level(model: Model, level: ThinkingLevel) -> ThinkingLevel

Clamp level to the nearest supported level for model.

If level is already supported, return it unchanged. Otherwise search upward first (higher intensity), then downward, through the ordered level list to find the closest available level.

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get_supported_thinking_levels

function

get_supported_thinking_levels(model: Model) -> list[ThinkingLevel]

Return the thinking levels supported by model.

• Non-reasoning models only support ["off"].
• For reasoning models, levels are filtered through the model's thinking_level_map. A level mapped to None is unsupported. "xhigh" is only included when it has an explicit (non-None) mapping. All other levels are included by default when the map omits them.

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models_are_equal

function

models_are_equal(a: Model | None, b: Model | None) -> bool

Return True if a and b refer to the same model.

Comparison is by id and provider_id. Returns False when either argument is None.

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