What's New in Mellea 0.4.0 + Granite Libraries Release

Back to Articles What's New in Mellea 0.4.0 + Granite Libraries Release Enterprise Article Published March 20, 2026 Upvote 3 Abraham Daniels abedaniels Follow ibm-granite Overview We have released Mellea 0.4.0 alongside three Granite Libraries: granitelib-rag-r1.0,granitelib-core-r1.0,granitelib-guardian-r1.0. Together, these releases make it easier to build structured, verifiable, and safety-aware AI workflows on top of IBM Granite models. Mellea is an open-source Python library for writing generative programs -- replacing probabilistic prompt behavior with structured, maintainable AI workflows. Unlike general-purpose orchestration frameworks, Mellea is designed to make LLM-based programs maintainable and predictable through constrained decoding, structured repair loops, and composable pipelines (New to Mellea? Start with our introductory blog and meet the team) Mellea 0.4.0 Mellea 0.4.0 is the latest release of an open-source research project initiated and developed by IBM Research. Building on 0.3.0 foundational libraries and workflow primitives, 0.4.0 expands the library's integration surface and introduces new architectural patterns for structuring generative workflows. What’s included: Native integration with the Granite Libraries, offering a standardized API that relies on constrained decoding to guarantee schema correctness. Instruct-validate-repair pattern via rejection sampling strategies Observability hooks for event-driven callbacks to monitor and track workflo...