fireworks-ai

Provides a standardized Python client interface that abstracts multiple LLM providers (Fireworks, OpenAI-compatible endpoints, and other inference backends) behind a single API. Uses a provider-agnostic request/response schema that maps to each backend's native API format, enabling seamless model switching without code changes. Implements connection pooling and request batching for efficient resource utilization across distributed inference endpoints.

Implements server-sent events (SSE) streaming for real-time token generation with built-in backpressure handling to prevent memory overflow when consuming tokens faster than they arrive. Uses async iterators and generator patterns to allow incremental token consumption without buffering entire responses. Handles connection interruptions and partial token sequences gracefully with automatic reconnection and state recovery.

Provides structured logging and observability hooks for monitoring API calls, latency, errors, and token usage. Integrates with standard Python logging and supports custom handlers for metrics collection. Logs include request/response metadata, timing information, and error details for debugging and performance analysis.

Provides a batch processing interface that accepts large lists of prompts and automatically chunks them into API-compliant batch sizes, submitting them in parallel while respecting rate limits. Aggregates results back into the original order and handles partial failures with retry logic. Implements exponential backoff for transient errors and exposes detailed error reporting per-batch item.

Provides a structured function-calling interface that accepts Python function signatures or JSON schemas, validates LLM-generated tool calls against the schema, and automatically coerces response types to match declared parameter types. Uses Python's inspect module to extract type hints from functions and converts them to OpenAI-compatible tool schemas. Implements a call dispatcher that routes validated function calls to registered handlers with type safety.

Manages conversation history and context windows by tracking token counts, automatically truncating or summarizing older messages when approaching model limits, and maintaining semantic coherence across truncation boundaries. Uses token counting APIs to estimate message sizes and implements configurable truncation strategies (sliding window, importance-based, or LLM-generated summaries). Preserves system prompts and recent messages while compressing historical context.

Enforces structured output formats (JSON, YAML, or custom schemas) by specifying response_format parameters and validating LLM outputs against declared schemas before returning to the application. Uses JSON schema validation libraries to check structure, type, and constraint compliance. Implements fallback parsing strategies (e.g., extracting JSON from markdown code blocks) when LLM outputs are malformed.

Automatically routes requests to different models or providers based on configurable criteria (prompt complexity, latency requirements, cost budgets, or model capabilities). Implements a routing policy engine that evaluates conditions at request time and selects the optimal model. Supports A/B testing by probabilistically routing requests to different models and collecting performance metrics.

Provides accurate token counting for prompts and completions using model-specific tokenizers, enabling cost estimation before making API calls. Implements caching of tokenizer instances and supports batch token counting for efficiency. Calculates estimated costs based on model pricing and token counts, with support for different pricing tiers and volume discounts.

Implements automatic retry logic for transient failures (rate limits, timeouts, temporary service unavailability) using exponential backoff with jitter to prevent thundering herd problems. Configurable retry budgets and maximum wait times prevent infinite retries. Distinguishes between retryable errors (429, 503) and permanent failures (401, 404) to avoid wasting retries on unrecoverable errors.

Provides full async/await support using Python's asyncio, allowing concurrent inference requests without blocking. Implements connection pooling with configurable concurrency limits to prevent overwhelming the API or local resources. Supports both async context managers and traditional callback patterns for flexibility.