6 Best Agency Alternatives in 2026 (Open Source)

Agency — 🕵️‍♂️ Library designed for developers eager to explore the potential of Large Language Models (LLMs) and other generative AI through a clean, effective, and Go-idiomatic approach. vs LangChainGo: Go-native design from scratch (not a Python port) — composable operations, interceptors, and multimodal support with clean Go-idiomatic architecture

Short answer

  • Closest match to Agency: LangChain Go.
  • Most actively developed: txtai (235 commits in the last 90 days).
  • Fastest growing: Semantic Kernel (+165 GitHub stars in the last 30 days).
  • No commit in 6+ months: LangChain Go, Agentflow and LangChain Rust.

These 6 open-source tools do the same job. They are ordered by how closely they match Agency, with live GitHub data so you can see which projects are actively maintained.

ToolGitHub starsStars / 30dLast commit
Agency(original)515+12024-12-30
LangChain Go9.7k+1172026-01-11
Agency Swarm4.6k+742026-10-02
Agentflow32102023-08-11
Semantic Kernel28.6k+1652026-10-01
txtai13.0k+1012026-10-02
LangChain Rust1.3k+132025-04-30
  1. 1. LangChain Go

    LangChain for Go, the easiest way to write LLM-based programs in Go

    What sets it apart: It brings LangChain's composable LLM application model to the Go ecosystem.

    Best for: Go developers building LLM applications; Teams implementing LangChain-style agents and workflows in Go

  2. 2. Agency Swarm

    Reliable Multi-Agent Orchestration Framework

    What sets it apart: Multi-agent framework modeling real-world organizational structures with directional communication flows — vs CrewAI (role-based but less control) or AutoGen (conversation-centric)

    Best for: Building multi-agent systems modeled as organizational structures; Teams wanting full control over agent instructions and communication; Production multi-agent deployments with typed tools

  3. 3. Agentflow

    Complex LLM Workflows from Simple JSON.

    What sets it apart: vs AutoGPT / LangChain agents: deterministic step-by-step workflow execution from JSON definitions — balanced between chat flexibility and autonomous agent unpredictability, with custom function support

    Best for: Developers wanting structured, repeatable LLM workflows vs. freeform chat; Multi-step content generation pipelines (e.g., market research → analysis → report); Teams needing predictable LLM execution with human-readable workflow definitions

  4. 4. Semantic Kernel

    Integrate cutting-edge LLM technology quickly and easily into your apps

    What sets it apart: vs LangChain: enterprise-grade with native .NET/C#/Java support and Microsoft backing; vs CrewAI: more flexible plugin architecture with MCP support and process framework

    Best for: Enterprise .NET/C# shops building AI agents; Multi-agent systems requiring complex orchestration; Teams already invested in Azure ecosystem

  5. 5. txtai

    💡 All-in-one AI framework for semantic search, LLM orchestration and language model workflows

    What sets it apart: All-in-one framework combining vector search, LLM orchestration, agents, and multi-modal pipelines — unlike LangChain (orchestration-only) or Weaviate (DB-only), txtai covers the full stack from indexing to agents

    Best for: Building end-to-end semantic search + RAG applications in Python; Teams wanting a single framework for embeddings, LLM orchestration, and agents; Multi-modal search across text, images, audio, and video

  6. 6. LangChain Rust

    🦜️🔗LangChain for Rust, the easiest way to write LLM-based programs in Rust

    What sets it apart: vs Python LangChain: native Rust with compile-time type safety, zero-cost abstractions, and memory safety for performance-critical LLM applications

    Best for: Rust teams building LLM-powered applications with type safety; Performance-critical LLM services in Rust backend systems

FAQ

What are the best alternatives to Agency?
The closest open-source alternatives to Agency are LangChain Go, Agency Swarm and Agentflow, followed by Semantic Kernel, txtai and LangChain Rust. They are ranked by how closely they match what Agency does.
Which Agency alternative is the most popular?
Semantic Kernel has the most GitHub stars among Agency alternatives, with 28,620 stars.
Which Agency alternative is the most actively maintained?
By recent activity, txtai (235 commits in the last 90 days) is the most actively developed alternative.