Agctor

A .NET 8 actor-model framework for building agentic systems: isolated actors, async message passing, LLM agents, tools, and an HTTP + MCP host.

If you use Agctor, please keep the copyright notices and NOTICE file, and cite the project with CITATION.cff.

Why actor model

Agents in Agctor are actors. Each one owns its state, receives messages one at a time, and talks to other agents only through envelopes. That keeps LLM calls, tool execution, and human input isolated instead of sharing a global workflow object.

Features

• Actor runtime with a pluggable adapter (in-memory is implemented; Orleans and Proto.Actor adapters are placeholders)
• Agents: LLM (Ollama), human/CLI, and tool actors
• Tools: C# and Python code execution, filesystem, code editor
• Timeouts as a supervisor actor, with progress and partial results
• Host: REST API, Swagger, and a TCP MCP listener
• CLI for sending a prompt to a root agent
• Observability: logging, metrics, and visualization helpers

Requirements

• .NET 8 SDK
• Optional: Ollama with a local model (default mistral) for LLM agents

Quick start

dotnet restore Agctor.sln
dotnet build Agctor.sln

Run the host:

dotnet run --project AgctorSDK.Host

• REST / Swagger: http://localhost:5000/swagger (see launchSettings.json for the exact URL)
• MCP: 127.0.0.1:8080 (loopback by default — see SECURITY.md)

Run a prompt through the CLI:

dotnet run --project AgctorCLI -- "Summarize the actor model in one sentence"

Testing

dotnet test AgctorSDK.Core.Tests
dotnet test AgctorSDK.Core.IntegrationTests
dotnet test AgctorSDK.Host.IntegrationTests

Tests tagged RequiresOllama need a running Ollama daemon. CI runs everything else.

Repository layout

AgctorSDK.Core/                 # Contracts, messages, timeouts, observability
AgctorSDK.Agents/               # Agent actors and in-memory runtime
AgctorSDK.Tools/                # Tool actors (code, files)
AgctorSDK.Extensions/           # DI: AddAgctor()
AgctorSDK.Host/                 # HTTP + MCP gateway
AgctorCLI/                      # Command-line runner
AgctorSDK.Core.Tests/           # Unit tests
AgctorSDK.Core.IntegrationTests/
AgctorSDK.Host.IntegrationTests/
Demo/                           # Visualization samples
Project/                        # Product requirements (not source)

Using it as a library

using AgctorSDK.Core.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;

var services = new ServiceCollection();
services.AddAgctor(); // in-memory runtime by default

Packable projects (Core, Agents, Tools, Extensions) are Apache-2.0 and include LICENSE + NOTICE in the nupkg.

Security

Code execution and filesystem tools run in-process with no sandbox. The host has no authentication yet. Use Agctor only in environments you trust. Details: SECURITY.md.

Contributing

Please read CONTRIBUTING.md. Bug reports and small, tested PRs are the fastest path to a merge.

Citation

# GitHub: use "Cite this repository" from CITATION.cff

License

Copyright 2026 Raha Mohebbi and Agctor contributors.

Licensed under the Apache License, Version 2.0. You must retain attribution (copyright headers / NOTICE) when you redistribute. See NOTICE.