EmberLM

EmberLM provides a specialized developer workspace for prompt engineering, streamlining the entire lifecycle from experimentation to deployment. Key capabilities include: * Side-by-side output comparison across multiple language models * Customizable evaluation rules for response quality assessment * Regression testing to detect quality degradation * Visual debugger for MCP servers * Detailed cost tracking per model and prompt * Seamless production deployment with a concise SDK This platform allows developers to compare responses from leading language models such as Claude, GPT-5, and Gemini, viewing speed, cost, and quality metrics in a single interface. Users can define specific evaluation rules, including LLM-as-a-Judge scoring, regex checks, and JSON schema validation, to ensure outputs meet desired criteria. Full prompt versioning with diffs enables branching, tagging, and rolling back changes like traditional code. The workspace integrates a visual inspector for debugging MCP servers, auto-discovering tools and displaying full JSON-RPC traces. It supports regression testing by saving 'golden responses' and running tests on every prompt modification to instantly identify quality drops. Additionally, developers can track spending across all providers, gaining insights into cost per prompt, feature, and model. Batch testing with CSV uploads allows for scalable evaluation of hundreds of inputs. EmberLM is designed for engineering teams focused on building and optimizing language model applications. It serves as a comprehensive environment for robust testing, precise evaluation, and confident deployment of prompting strategies, ensuring consistent performance and cost-efficiency.