Stream markdown
This example shows how to stream markdown from an agent, using the rich library to highlight the output in the terminal.
It'll run the example with both OpenAI and Google Gemini models if the required environment variables are set.
Demonstrates:
Running the Example
With dependencies installed and environment variables set, run:
python -m pydantic_ai_examples.stream_markdown uv run -m pydantic_ai_examples.stream_markdown Example Code
stream_markdown.py
"""This example shows how to stream markdown from an agent, using the `rich` library to display the markdown. Run with: uv run -m pydantic_ai_examples.stream_markdown """ import asyncio import os import logfire from rich.console import Console, ConsoleOptions, RenderResult from rich.live import Live from rich.markdown import CodeBlock, Markdown from rich.syntax import Syntax from rich.text import Text from pydantic_ai import Agent from pydantic_ai.models import KnownModelName # 'if-token-present' means nothing will be sent (and the example will work) if you don't have logfire configured logfire.configure(send_to_logfire='if-token-present') logfire.instrument_pydantic_ai() agent = Agent() # models to try, and the appropriate env var models: list[tuple[KnownModelName, str]] = [ ('google-gla:gemini-2.5-flash', 'GEMINI_API_KEY'), ('openai:gpt-5-mini', 'OPENAI_API_KEY'), ('groq:llama-3.3-70b-versatile', 'GROQ_API_KEY'), ] async def main(): prettier_code_blocks() console = Console() prompt = 'Show me a short example of using Pydantic.' console.log(f'Asking: {prompt}...', style='cyan') for model, env_var in models: if env_var in os.environ: console.log(f'Using model: {model}') with Live('', console=console, vertical_overflow='visible') as live: async with agent.run_stream(prompt, model=model) as result: async for message in result.stream_output(): live.update(Markdown(message)) console.log(result.usage()) else: console.log(f'{model} requires {env_var} to be set.') def prettier_code_blocks(): """Make rich code blocks prettier and easier to copy. From https://github.com/samuelcolvin/aicli/blob/v0.8.0/samuelcolvin_aicli.py#L22 """ class SimpleCodeBlock(CodeBlock): def __rich_console__( self, console: Console, options: ConsoleOptions ) -> RenderResult: code = str(self.text).rstrip() yield Text(self.lexer_name, style='dim') yield Syntax( code, self.lexer_name, theme=self.theme, background_color='default', word_wrap=True, ) yield Text(f'/{self.lexer_name}', style='dim') Markdown.elements['fence'] = SimpleCodeBlock if __name__ == '__main__': asyncio.run(main())