Overview - Pantheon Documentation

Pantheon today

Pantheon runs stateful agents behind a REST API. Your application owns its UI and business data.

Pantheon stores session events, streams live output, and pauses runs for application tools.

Base URL
https://pantheon-todo.alethiconsulting.com/pantheon-api

Object	What you use it for
Agent	Set instructions, model, tool requirements, and sandbox policy.
Tool	Describe an application tool with input and output schemas.
Deployment	Publish one agent version with its tool definitions.
Session	Keep conversation state and a pinned deployment.
Run	Process one turn. A session allows one active run.
Event	Report durable state or ephemeral live output.

Create an API key. Then set the two required variables.

Terminal

export PANTHEON_BASE_URL="https://pantheon-todo.alethiconsulting.com/pantheon-api"
export PANTHEON_API_KEY="PANTHEON_API_KEY"

Give your agent the docs link: https://pantheon-todo.alethiconsulting.com/docs/.

Include llms-full.txt for all page content. Use llms.txt for the page index.

Install the SDK. Copy a starter file from the chat components page.

Follow Build on Pantheon to publish your agent and connect your application.

Goal	Guide
Build the complete first flow	Quickstart
Create and revoke an API key	Get an API key
Run Pantheon on your infrastructure	Self-host
Add a ready-made chat surface	Chat components
Execute tools in your application	Application tools
Manage state and concurrency	Sessions and runs
Render and reconnect streams	Events
Recover from failures	Errors
Check current limitations	Known issues
Inspect routes and schemas	API reference

MCP tools do not run: Use application tools. Stored MCP server settings are not dispatched by the runtime.
A session rejects a second run: Finish, resume, or cancel the active run before sending another.
New contract examples are thin: Use the API reference with the task guides.