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symfonic-core

New code starts with symfonic.Agent and symfonic.platform.AgentHost.

SymfonicAgent and AgentBuilder: removed in 11.3.0

From 11.3.0, SymfonicAgent(...) and AgentBuilder().build() raise EntryPointRemovedError, a migration error, before anything is built, with no compatibility shim. symfonic-core==9.12.* is the newest public PyPI line on which both still construct (private 11.0 to 11.2.6 did too), but it predates the 11.x features, so pinning it does not migrate an 11.x application. Read Moving to 11.0 and Guide 22 to migrate.

The Agent Graph Framework. Build AI agents with a five-layer Hierarchical Memory System, streaming, tool routing, fabrication detection, and durable persistence — all default-preserving, so you adopt one knob at a time.

  • Get started in minutes

    Install the package and compose your first agent with the kernel.

    The Simple Agent

  • Understand the model

    The agent, the 5-Pentad memory system, streaming, and the runtime graph.

    Core Concepts

  • Every feature, mapped

    One page listing all 11 capability clusters with minimal and opt-in snippets.

    Feature Catalog

  • Reference the source

    Auto-generated API docs for every public module, always in sync with the code.

    API Reference

Install

This site may describe a newer private Gitea release than public PyPI offers. By default, the commands below install from PyPI and may lack features documented here. For a private release, use your approved registry configuration and pin the verified wheel.

pip install symfonic-core

Add the provider you use as an extra:

pip install "symfonic-core[anthropic]"

pip install "symfonic-core[openai]"

pip install "symfonic-core[google]"

pip install "symfonic-core[aws]"

pip install "symfonic-core[openrouter]"

pip install "symfonic-core[ollama]"

Your first agent

from symfonic import Agent
from symfonic.core.testing import MockModelProvider

agent = Agent(MockModelProvider(response="Hello!"))

result = await agent.run("Hi there")
print(result.text)

One required dependency, no configuration object, no tenant scope, no context manager. That is the whole first rung — Guide 00 is the ten-minute version.

The ladder

Everything else is one rung up, and you climb only as far as you need.

Rung What you get Start here
1 The simple agent — one provider, tools, one turn The Simple Agent
2 Capabilities — tools, prompts, memory, knowledge, delegation, safety Memory · Writing Tools
3 Runtime services — sessions, checkpoints, budgets, cost Conversation Persistence
4 Platform — tenancy, HTTP and SSE, privacy, billing Production
5 Integrations — providers, backends, MCP, plugins, OpenTelemetry Model Providers
6 Low-level core — the kernel, contracts, the event stream Architecture

Already running SymfonicAgent? From 11.3.0 it refuses construction (see the notice above), so move before you upgrade: Guide 22 maps the legacy patterns it covers to Agent capabilities, and Agent does not accept the same arguments, so migrate by composition rather than by renaming the call.

Where to go next

I want to… Start here
Write my first agent The Simple Agent · Quickstart
Run an agent and stream its output Quickstart · Streaming & Callbacks
Give my agent durable memory Memory & Persistence · Memory concept
Add tools and route to them Intent & Tool Routing · Lazy Tooling
Build a business domain plugin Plugins & Domains
Ship to production Production · Production Adopter Pattern
Scaffold a full app Scaffold a Project · Store Starter
Find where a feature I use lives now Feature Preservation Reference · Guide 22