Agentic workflows

Insert a message. The model picks a tool, invoke_tools runs it, and both results are columns on that row. Create the tables with pxt schema update app.py my_app, then open them with t = pxt.get_table('my_app.assistant'). Cookbooks on this topic use pxt.create_table() so you can run cells without a project. An app puts the same columns on a TableModel in app.py and creates the tables with pxt schema update.

import pixeltable as pxt
import pixeltable.functions as pxtf
from pixeltable.serving import FastAPIRouter

TableModel = pxt.model_base()


@pxt.udf
def get_weather(city: str) -> str:
    return f'Weather in {city}: 72°F, sunny'


tools = pxt.tools(get_weather)


class Assistant(TableModel, name='assistant'):
    message: pxt.String
    response = pxtf.openai.chat_completions(
        messages=[{'role': 'user', 'content': message}],
        model='gpt-4o-mini',
        tools=tools,
    )
    tool_output = pxtf.openai.invoke_tools(tools, response)


ask = FastAPIRouter(name='ask')
ask.add_insert_route(
    Assistant, path='/ask', inputs=[Assistant.message], outputs=[Assistant.tool_output]
)

pxt schema update app.py my_app
pxt service update app.py my_app

assistant = pxt.get_table('my_app.assistant')
assistant.insert([{'message': 'Weather in Paris?'}])
assistant.select(assistant.message, assistant.tool_output).collect()

pxt service list prints the URL. POST /ask with {"message": "..."}. Chat history is another table with an embedding index: Agent memory. MCP tools load with pxt.mcp_udfs(...) and go into the same pxt.tools() list. A full chat app: uvx pixeltable-new copies the starter kit agent. Pass agent as the last argument to pxt schema update. /ask needs ANTHROPIC_API_KEY. On Cloud, create an API key in the dashboard, set PIXELTABLE_API_KEY, then run pxt db update, pxt schema update, and pxt service update against pxt://org:mydb. Search over chunks instead of tools: RAG and live APIs. Coming from LangGraph: Migrate.

Tool calling

Agentic patterns

Patterns for agents as tables.

RAG pipeline

Search over chunks instead of tools.

HTTP serving

POST /ask from the same file.

Use Cases

Topics

Tool calling

Agentic patterns

RAG pipeline

HTTP serving