Mirascope is an open-source Python library described as "The LLM Anti-Framework," designed to give developers a unified, provider-agnostic interface for working with large language models without the heavy abstractions of traditional agent frameworks. It supports providers including OpenAI, Anthropic, Mistral, Gemini, Groq, Cohere, LiteLLM, Azure AI, Vertex AI, and AWS Bedrock under a single consistent API surface. The library positions itself as a "Goldilocks API" that preserves the fine-grained control of raw provider SDKs while adding type safety, structured outputs via Pydantic models, and ergonomic tooling for chaining LLM calls, streaming responses, and building agentic pipelines. Developers can define Response Models with strict type hints so LLMs return structured, validated data rather than raw text. Mirascope is accompanied by Lilypad, a companion open-source project for LLM observability, versioning, tracing, and annotation. Lilypad wraps LLM functions with automatic versioning (capturing the full closure context) and produces OpenTelemetry-compatible traces, enabling teams to replay inputs, audit prompt changes, and run a playground for non-technical prompt editing. The hosted Mirascope platform offers tiered plans (Free, Pro at $49/month, Team at $199/month) that layer managed tracing quotas, longer retention, and team collaboration on top of the open-source core. As of early 2026, the main mirascope PyPI package was at version 2.4.0 with ~1.4k GitHub stars and the repository last updated in February 2026, indicating active maintenance. Mirascope targets Python developers building production LLM applications who want provider flexibility without vendor lock-in and without sacrificing type safety or observability. It is distributed under the MIT License. Key features: - Unified provider-agnostic API covering OpenAI, Anthropic, Gemini, Groq, Cohere, Azure AI, Vertex AI, Bedrock, and LiteLLM - Structured outputs via Pydantic Response Models with strict type hints and JSON Mode - Lilypad companion: automatic versioning and tracing of LLM function closures with OpenTelemetry support - Decorators for LLM calls, streaming, chaining, and tool/function-call definitions - Support for locally hosted open-source models via OpenAI-compatible client override - Hosted platform with managed tracing, longer retention, and team collaboration (Pro/Team plans) - Playground UI for non-technical users to edit prompts without touching code - MIT-licensed open-source core with active PyPI releases (v2.4.0 as of early 2026)
Free ($0/month, 1 seat, 1 project); Pro ($49/month); Team ($199/month)