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Context Management for Pydantic AI

Automatic conversation summarization and context management for Pydantic AI agents.

Context Management for Pydantic AI helps your agents handle long conversations without exceeding model context limits. Choose between intelligent LLM summarization or fast sliding window trimming.

  • Intelligent Summarization

    LLM-powered compression that preserves key information

  • Sliding Window

    Zero-cost message trimming for maximum speed

  • Safe Cutoff

    Never breaks tool call/response pairs

  • Flexible Configuration

    Message, token, or fraction-based triggers

Available Processors

Processor LLM Cost Latency Context Preservation Best For
SummarizationProcessor High High Intelligent summary Quality-focused apps
SlidingWindowProcessor Zero ~0ms Discards old messages Speed/cost-focused apps

Quick Start

Intelligent Summarization

Uses an LLM to create summaries of older messages:

Python
from pydantic_ai import Agent
from pydantic_ai_summarization import create_summarization_processor

processor = create_summarization_processor(
    trigger=("tokens", 100000),
    keep=("messages", 20),
)

agent = Agent(
    "openai:gpt-4o",
    history_processors=[processor],
)

result = await agent.run("Hello!")

Zero-Cost Sliding Window

Simply discards old messages — no LLM calls:

Python
from pydantic_ai import Agent
from pydantic_ai_summarization import create_sliding_window_processor

processor = create_sliding_window_processor(
    trigger=("messages", 100),
    keep=("messages", 50),
)

agent = Agent(
    "openai:gpt-4o",
    history_processors=[processor],
)

result = await agent.run("Hello!")

Choosing a Processor

Use SummarizationProcessor when:

  • Context quality is critical
  • You need to preserve key information from long conversations
  • LLM cost is acceptable for your use case

Use SlidingWindowProcessor when:

  • Speed and cost are priorities
  • Recent context is most important
  • You're running many parallel conversations
  • You want deterministic, predictable behavior
Package Description
Pydantic Deep Agents Full agent framework (uses this library)
pydantic-ai-backend File storage and Docker sandbox
pydantic-ai-todo Task planning toolset
subagents-pydantic-ai Multi-agent orchestration
pydantic-ai The foundation — agent framework by Pydantic

Next Steps