Releases·Tool Release
pydantic-ai v2.53.0 patches high-severity concurrency slot leak in ConcurrencyLimitedModel streaming
Pydantic released pydantic-ai v2.53.0, patching a high-severity security issue in ConcurrencyLimitedModel that could exhaust concurrency slots and block all requests sharing a limiter. The release also adds new CLAI2 plugins, managed subagents, a ToolCallJudge, and numerous fixes.
0 engagement1 sourceThu, Oct 1, 2026, 12:00 AM
AI Overview
- v2.53.0 fixes high-severity GHSA-6fqq-452j-qhrp: streamed requests through ConcurrencyLimitedModel could keep concurrency slots after early exits, blocking limiter-sharing requests (#9478)
- The fix makes limiters raise UserError when shared with the agent or an enclosing wrapper, and requires AbstractConcurrencyLimiter to allow cross-task release(); v1 unaffected
- v2.53.0 adds ToolCallJudge pre-execution tool-call assessment, managed subagents in CLAI2, and repair_messages message-history repair exposure
- New CLAI2 plugins include posthog, grain, linear, herdr, and opt-in Logfire telemetry with a setup menu
- Bug fixes make OpenAIResponsesModel, OpenAIChatModel, and OpenRouterModel build identical ModelResponse from streamed and complete responses
- New SystemOneModel runs decision models like CLM and Laya over the /v1/systemone API; TestModel gains oneOf schema support
Related
Releases·Tool Release
Pydantic AI v2.52.0 patches moderate web_fetch DoS (GHSA-v36g-jcw9-x7cw), ships Harness and CLAI 2
Pydantic AI released v2.52.0 on 2026-09-29, fixing a moderate security issue (GHSA-v36g-jcw9-x7cw) in the local web_fetch tool, with the fix backported to v1.107.7. The release also moves pydantic-ai-harness into the main repository and ships the first pydantic-clai2 release. Users on affected versions should upgrade.
Pydantic AI released v2.52.0 on 2026-09-29, fixing a moderate security issue (GHSA-v36g-jcw9-x7cw) in the local web_fetch tool, with the fix backported to v1.107.7. The release also moves pydantic-ai-harness into the main repository and ships the first pydantic-clai2 release. Users on affected versions should upgrade.
6 engagement2 sourcesgithubTue, Sep 29, 2026, 12:00 AM
Releases·Tool Release
pydantic-ai v2.42.0 adds GitHub Copilot provider, rejects invalid DeferredToolResults approvals
Pydantic released six consecutive pydantic-ai versions (v2.38.0–v2.43.0, 2026-09-03 to 2026-09-11). Highlights include support for OpenAI gpt-6-astra and gemini-3.8-flash, Claude Fable 5.1 and Mythos 5.1, a vLLM provider, a GitHub Copilot provider, ChatGPT/Codex subscription auth, context-window tracking, barge-in handling in realtime sessions, and an @agent.on_event listener API. The releases matter to practitioners building agents who need current model support, cost tracking, and realtime voice control.
Pydantic released six consecutive pydantic-ai versions (v2.38.0–v2.43.0, 2026-09-03 to 2026-09-11). Highlights include support for OpenAI gpt-6-astra and gemini-3.8-flash, Claude Fable 5.1 and Mythos 5.1, a vLLM provider, a GitHub Copilot provider, ChatGPT/Codex subscription auth, context-window tracking, barge-in handling in realtime sessions, and an @agent.on_event listener API. The releases matter to practitioners building agents who need current model support, cost tracking, and realtime voice control.
Updated Sat, Sep 12, 2026, 12:54 AM — v2.43.0 (2026-09-11) adds a first-run clai session banner and fixes OpenAI text-part boundaries after tool calls
0600 engagement6 sourcesgithubThu, Sep 3, 2026, 07:48 AM
Releases·Tool Release
Pydantic releases pydantic-ai v2.19.0 with improved error handling and bug fixes
Pydantic released version 2.19.0 of pydantic-ai, adding headers and retry_after fields to ModelHTTPError, populating them from all provider SDKs. The release also fixes a bug where absorbed external cancellation is re-asserted at run step boundaries, and updates the FastMCP dependency range to <4.
Pydantic released version 2.19.0 of pydantic-ai, adding headers and retry_after fields to ModelHTTPError, populating them from all provider SDKs. The release also fixes a bug where absorbed external cancellation is re-asserted at run step boundaries, and updates the FastMCP dependency range to <4.
0 engagement1 sourcegithubMon, Jul 27, 2026, 12:00 AM
Releases·Tool Release
pydantic/pydantic-ai v2.48.0 adds OpenAI gpt-6-sol/gpt-6-luna and Claude Opus 5.5 support
Pydantic released pydantic-ai v2.48.0 on 2026-09-22, adding model support for OpenAI's gpt-6-sol and gpt-6-luna, Anthropic's claude-opus-5-5, and new OpenAI audio models via genai-prices 0.1.7. It also fixes message-ID preservation in Vercel AI and AG-UI adapters and bumps genai-prices to 0.1.8.
Pydantic released pydantic-ai v2.48.0 on 2026-09-22, adding model support for OpenAI's gpt-6-sol and gpt-6-luna, Anthropic's claude-opus-5-5, and new OpenAI audio models via genai-prices 0.1.7. It also fixes message-ID preservation in Vercel AI and AG-UI adapters and bumps genai-prices to 0.1.8.
0 engagement1 sourcegithubTue, Sep 22, 2026, 12:00 AM
Releases·Tool Release
pydantic/pydantic-ai v2.47.0 names None output routes and hardens TypeSafeModel handling
Pydantic released pydantic-ai v2.47.0 on 2026-09-21, adding TypeSafeModel routing improvements and stricter validation of user prompt content. The release includes compatibility notes that change route naming and error behavior.
Pydantic released pydantic-ai v2.47.0 on 2026-09-21, adding TypeSafeModel routing improvements and stricter validation of user prompt content. The release includes compatibility notes that change route naming and error behavior.
0 engagement1 sourcegithubMon, Sep 21, 2026, 12:00 AM