Medium · published October 8, 2026
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 0.3.4 until 1.107.4 and 2.27.1, OpenTelemetry instrumentation configured with InstrumentationSettings(include_content=False) can export retry prompts outside tool calls in gen_ai.input.messages and pydantic_ai.all_messages. Agents using NativeOutput, PromptedOutput, or output validators on text output can therefore disclose validation feedback, including invalid model values quoted by that feedback, to readers of the telemetry backend. Tool-call retries and deployments that do not use include_content=False are not affected by this specific path. This issue is fixed in versions 1.107.4 and 2.27.1.
| Product | Versions | Fixed in |
|---|---|---|
| pydantic/pydantic_ai | ≥ 0.3.4, < 1.107.4 | 1.107.4 |
| pydantic/pydantic_ai | ≥ 2.0.0, < 2.27.1 | 2.27.1 |