Praxo.Core 0.9.1

PRAXO-CORE C# Core

PRAXO-CORE is an embeddable, MIT-licensed agent framework. This package is its native .NET Core: an agent loop with tool registration and dispatch, policy hooks, typed events, memory, checkpoints, context budgets, middleware, JSON Schema validation, and plugin manifest parsing. It runs in-process and does not require a hosted service.

• SPEC_VERSION: 0.2.0
• Source version: 0.9.0 (latest source tag csharp/v0.9.0)
• License: MIT
• Dependencies: none beyond the .NET base class library
• The latest NuGet package is Praxo.Core@0.8.0.

Registry and Coding-Agent Entry

• Registry introduction: REGISTRY.md
• Machine-readable entry: llms.txt and llms.md
• Examples: runnable language-specific examples.
• Coding-agent contract: docs/getting-started/coding-agents.md
• Registry: NuGet
• Community: (https://x.com/axisvela) · Weibo

Get started

Install the published package:

dotnet add package Praxo.Core --version 0.9.0

Then run the smallest deterministic example:

• Consumer starter: explicit tool scope and a deny check.
• Live model: connect an OpenAI-compatible endpoint and register get_time.

See the C# documentation for the full API and the language matrix for current scope.

Examples

Runnable examples live under language/csharp/examples.

Install

dotnet add package Praxo.Core --version 0.9.0

Scope

The Core implements all eleven vector groups: toolcall, jsonschema, plugin, checkpoint, event, memory, policy, stream, context, middleware, and agent loop. It also includes a synchronous OpenAiCompatibleModel and a streaming variant. The agent loop supports RunStream, cooperative cancellation through AgentOptions.CancellationToken, bounded parallel tool execution through AgentOptions.MaxParallelTools, and human-in-the-loop interrupt decisions through AgentOptions.InterruptOn and OnInterruptDecision. The public API is idiomatic C#; wire shapes keep the Go casing (image_url, runId, plugin_id).

Build and test

dotnet build language/csharp/Praxo.Core/Praxo.Core.csproj
dotnet run --project language/csharp/Praxo.Conformance
dotnet run --project language/csharp/Praxo.Tests
dotnet run --project language/csharp/Praxo.Conformance -- --check-api
dotnet run --project language/csharp/samples/VbSample

Local toolchain used by the repository maintainers lives at D:\dev\dotnet. On CI, use the standard actions/setup-dotnet job.

Quickstart

using Praxo.Core;

var model = new StaticModel("hello");
var agent = new Agent(new AgentOptions(model));
var result = agent.Run(new Session("demo"), "hello");
Console.WriteLine(result.Output);

Tools are registered on AgentOptions.Tools:

var registry = new ToolRegistry();
registry.Register(new FuncTool("echo", "Echo arguments", args => args.DeepClone()));

var agent = new Agent(new AgentOptions(model)
{
    Tools = registry,
    MaxSteps = 8,
});

Model adapters

• OpenAiCompatibleModel for OpenAI, DeepSeek, Kimi/Moonshot, OpenRouter, Groq, and Together endpoints.
• AnthropicModel for the Anthropic Messages API.
• GeminiModel for the Gemini generateContent API.

Each adapter accepts an injected HttpClient so tests can use a fake transport.

Harmovela event sink

HarmovelaSink posts lifecycle events to {BaseUrl}/events as JSON envelopes with spec_version, id, type, source, created_at, and a payload that merges the event data with session_id and run_id when present.

using Praxo.Core;

var options = new AgentOptions(model)
{
    Events = new HarmovelaSink(new HarmovelaSinkOptions
    {
        BaseUrl = "http://127.0.0.1:8790/aep/api",
    }),
};
var agent = new Agent(options);

Pass a HarmovelaTransport to inject a fake for tests. Limits: the sink adds no authentication, retries, buffering, acknowledgements, ordering, or exactly-once delivery. Filter sensitive event data at the caller, and use HTTPS for remote endpoints.

MCP stdio client

McpClient spawns a child process and speaks newline-delimited JSON-RPC 2.0. It performs the initialize / notifications/initialized handshake, follows tools/list cursors, rejects repeated cursors and duplicate names, preserves inputSchema, and maps tools/call structured or text content.

using System.Text.Json.Nodes;
using Praxo.Core;

using var client = new McpClient(new McpServerOptions
{
    Command = "my-mcp-server",
});
client.Connect();

var registry = new ToolRegistry();
client.RegisterTools(registry);

var result = client.CallTool("echo", new JsonObject { ["text"] = "hi" });

Registering MCP tools does not bypass policy: the agent still authorizes every tool.invoke action and applies its allowlist and middleware. Limits: stdio transport only, no remote transport or authentication, and MCP output remains untrusted content. Operations are bounded by the client timeout (default 30 seconds), timeouts send notifications/cancelled, and Close terminates the child process.

Layout

• Praxo.Core/ library.
• Praxo.Conformance/ vector runner and API snapshot tool.
• Praxo.Tests/ dependency-free core tests.
• samples/VbSample/ VB.NET consumer sample.
• api-snapshot.txt checked-in public API snapshot.

Release

Latest source tag: csharp/v0.9.0. It targets SPEC_VERSION 0.2.0. See CHANGELOG.md for per-release changes and compatibility notes.