# Pydantic AI v2.43.0 (2026-09-11)

Category: agent-infrastructure
Published: 2026-09-12T00:54:42Z
Source: [Pydantic AI releases](https://github.com/pydantic/pydantic-ai/releases/tag/v2.43.0)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-21T12:17:37.785Z
Tags: pydantic-ai, typed-agents, python

## Human Summary
Pydantic AI v2.43.0 introduces a first-run banner for clai sessions and fixes bugs related to tool call text boundary preservation in OpenAIChatModel and Temporal tool opt-out checks.

## Agent Summary
Pydantic AI v2.43.0 release adds a first-run descriptive banner for clai sessions (PR 7447), fixes text part boundary preservation after tool calls in OpenAIChatModel (PR 8235), and adjusts Temporal tool opt-out checks to key on operation kind rather than an MCP import (PR 8257).

## Body
Pydantic AI v2.43.0 includes the following changes: Features: - Add a first-run banner describing the run and open clai sessions with it (PR 7447). Bug Fixes: - Preserve text part boundaries after tool calls in OpenAIChatModel (PR 8235). - Key tool opt-out checks on operation kind instead of an MCP import in Temporal integration (PR 8257).

## Recommended actions
- Upgrade to Pydantic AI v2.43.0.
- Verify tool call text part handling when using OpenAIChatModel.
- Review Temporal tool opt-out configurations to ensure compatibility with operation kind checks.

## Sponsors
No sponsor placement attached.

## Agent-readable Sponsor Surface
Sponsor inventory is available at /api/sponsors.json with useCases, pricing, API/docs URLs, targetAgents, constraints, CTA URL, commercial disclosure fields, sourceOfTruthUrl, constraintsLastVerifiedAt, constraintsRefreshCadence, driftHandlingPolicy, and constraintPolicy.