Pi.Server 1.4.0

Pi.NET

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Pi.NET is a .NET 10 port of Pi. Pi is a minimal, extensible Agent harness (TypeScript monorepo, ~171k lines); this project ports its core libraries one by one to net10.0, bringing the same capabilities to the .NET ecosystem.

Pi's philosophy is "make Pi fit your workflow, not the other way around": each library does one minimal-but-complete thing, and you compose the layers above it yourself. This project carries that philosophy over — rather than mechanically translating TS into C#, it rebuilds everything in idiomatic C# with semantic equivalence (discriminated unions → abstract records with pattern matching, JS Proxy → explicit verb APIs).

<p align="center"> <a href="https://github.com/xuzeyu91/pi.net/blob/main/docs/media/pi-net-promo.mp4"> <img src="https://raw.githubusercontent.com/xuzeyu91/pi.net/main/docs/media/pi-net-promo-poster.png" alt="Pi.NET product promo" width="820"> </a> <br> _{39-second promo (with voice-over) · click the cover to play (1080p / MP4 / 5.4 MB)} </p>

What It Does

• Unified multi-provider LLM API — 10 built-in API implementations (openai-completions / openai-responses / openai-codex-responses / azure-openai-responses / anthropic-messages / google-generative-ai / google-vertex / mistral-conversations / bedrock-converse-stream / pi-messages) plus a full catalog of 42 built-in providers; streaming events, tool calls, thinking budgets, deferred responses, image generation (images) and text classification (classify); OAuth login flows for 9 providers (PKCE / RFC 8628 device code / loopback callback / refresh orchestration).
• Agent runtime — agent state machine with dual queues, the agent-loop main loop, sequential / parallel tool execution, abort / reset.
• MCP client — JSON-RPC protocol layer + in-memory / stdio / streamable-http transports + a complete OAuth layer (metadata discovery, PKCE authorization code, dynamic registration, credential-invalidation retry).
• Application orchestration runtime (Chord) — services and replicated state, delta engine, facets dependency graph with topological activation, external service source bindings.
• TCP RPC channel — handshake validation, request dispatch, cancellation, push — prepared for remotely controlling the coding-agent.
• Vendor-neutral telemetry — contracts + reference adapter + conformance test suite.

Packages

The TypeScript monorepo remains the behavioral reference. Bundled upstream docs and examples are retained as TypeScript references; use the .NET extension guide for C# extension APIs. The authoritative phase ledger, validation evidence, and documented TypeScript/.NET differences are in migration-execution-status.md.

Getting Started

Install from NuGet

All 13 libraries ship to nuget.org under their project names, targeting net10.0:

dotnet add package Pi.Ai        # unified multi-provider LLM API
dotnet add package Pi.Agent     # agent loop
dotnet add package Pi.Mcp       # MCP client
dotnet add package Pi.CodingAgent   # the whole stack, including the CLI runtime

Usage docs and samples

• docs/usage — how to consume each package from C#: which package for which job, minimal working code, credentials, and the traps worth knowing.
• samples — four runnable console projects, compiled by CI so they cannot silently rot:

dotnet run --project samples/Pi.Samples.FauxAgent      # full agent loop, no API key
dotnet run --project samples/Pi.Samples.RealModel -- anthropic   # streaming from a real model
dotnet run --project samples/Pi.Samples.CodingSession  # embedded coding agent (SDK)
dotnet run --project samples/Pi.Samples.McpClient      # standalone MCP client

Package contents, release process and rollback are documented in docs/publishing.md.

Build from source

Requires the .NET 10 SDK.

dotnet build Pi.slnx --no-restore
dotnet run --project src/Pi.Cli/Pi.Cli.csproj -- --help

Test projects use xUnit v3 with Microsoft.Testing.Platform. Run a test project directly:

dotnet run --project tests/Pi.Evals.Tests/Pi.Evals.Tests.csproj --no-restore

Migration Status

Implementation progress, phase-by-phase evidence, and known TypeScript/.NET differences are tracked in docs/migration-execution-status.md.