FastAgency is an open-source framework maintained by AIRT Technologies (airtai / ag2ai on GitHub) that bridges the gap between prototype and production for multi-agent AI applications. It provides a unified programming interface so developers write their core AG2 (formerly AutoGen) workflow logic once and run it across multiple interface targets without rewriting code. The framework supports three deployment targets out of the box: ConsoleUI for command-line interaction, MesopUI for a browser-based web interface (with no-auth, basic-auth, or Firebase auth modes), and a distributed FastAPI + NATS.io setup for high-scale production workloads. The NATS.io adapter uses FastStream under the hood to fan out tasks across multiple workers in multiple datacenters, making it the recommended path for large production deployments. A standout capability is one-line OpenAPI integration: point FastAgency at any OpenAPI spec and it auto-generates the API client and wires it directly into agent workflows. This dramatically reduces the boilerplate needed to connect agents to external services such as REST APIs, internal microservices, or third-party platforms. FastAgency is free and open-source (Apache 2.0 on PyPI as the `fastagency` package). The project is actively maintained under the ag2ai GitHub organization (mirrored from airtai), has a Discord community, and reached version 0.10.x as of 2025-2026. A companion project, fastagency-studio (airtai/fastagency-studio), provides a visual studio interface for building and managing workflows. Key features: - Unified programming interface: write workflow logic once, deploy to Console, Mesop web UI, or FastAPI - MesopUI web interface with no-auth, basic-auth, and Firebase authentication modes - NATS.io distributed adapter (via FastStream) for horizontally scalable production deployments - FastAPI adapter for serving workflows as authenticated REST endpoints - One-line OpenAPI spec import to auto-generate and attach external API clients to agents - CLI for running and managing workflows without a full GUI, suitable for DevOps pipelines - Built on top of AG2 (formerly Microsoft AutoGen) multi-agent runtime - Free and open-source under Apache 2.0; available via PyPI as `fastagency`
Free and open-source (Apache 2.0). No paid tiers listed.