[dependabot]

Bumps pydantic-ai-slim from 1.107.7 to 2.57.0.

Release notes

Sourced from pydantic-ai-slim's releases.

v2.57.0 (2026-10-15)

What's Changed

⚠️ Compatibility Notes

• Attach namespaced origin and tool_call_id metadata to BackgroundTools completions by @​michaeldunn9 in pydantic/pydantic-ai#10196
• Take GPT-Live realtime history, usage, and reply waits from the session core by @​DouweM in pydantic/pydantic-ai#10083
• Honour disable-model-invocation and user-invocable in Skills, and skip stray skill library paths by @​DouweM in pydantic/pydantic-ai#10378
• Take Gemini Live realtime history, usage, and reply waits from the session core by @​DouweM in pydantic/pydantic-ai#10082

🚀 Features

• Add MetaProvider for Meta Muse models, with meta: using the Responses API by @​mpfaffenberger in pydantic/pydantic-ai#10156
• Add Harness ApprovalReviewer to let a model approve low-risk tool calls before a person sees them by @​mpfaffenberger in pydantic/pydantic-ai#10143
• Price requests at their reported service tier by @​adtyavrdhn in pydantic/pydantic-ai#10244
• Add dataset_name to EvaluationReport by @​jirikuncar in pydantic/pydantic-ai#10307
• Forward MCP Apps tool results to AG-UI and Vercel AI frontends and add MCPToolset.read_resource_contents by @​adtyavrdhn in pydantic/pydantic-ai#10179
• Relay MCP Apps tool calls with MCPToolset.call_tool_for_app by @​adtyavrdhn in pydantic/pydantic-ai#10190

🐛 Bug Fixes

• Fix token-based compaction retaining too little recent history by @​AndrewTilson in pydantic/pydantic-ai#9784
• Record and stream one part per realtime output item when its transcript arrives late by @​pydanty in pydantic/pydantic-ai#10097
• Reference multimodal URL choices in the ToolReturnContent discriminator mapping by @​Kludex in pydantic/pydantic-ai#10239
• Stop OpenAIResponsesModel sending unavailable tool_choice names in allowed_tools by @​dsfaccini in pydantic/pydantic-ai#10232
• Send Gemini tool-call thought signatures (extra_content) back from OpenAIChatModel by @​dsfaccini in pydantic/pydantic-ai#10235
• Give a tool's prepare its own retry count under .prefixed(), .renamed() and PrefixTools by @​dsfaccini in pydantic/pydantic-ai#10219
• Support Gemini agentic media processing in GoogleModel by @​miguel-flowstate in pydantic/pydantic-ai#8028
• Stop granting native tool_search to gpt-5.4-nano by @​dsfaccini in pydantic/pydantic-ai#10272
• Omit unset optional fields from Vercel AI UIMessage JSON so the AI SDK accepts it by @​adtyavrdhn in pydantic/pydantic-ai#10175
• Keep Planning tool loops in the prompt cache, and attach a leading CachePoint to the previous user message on OpenRouterModel by @​mpfaffenberger in pydantic/pydantic-ai#10257
• Release concurrency slots after streamed request cleanup by @​dsfaccini in pydantic/pydantic-ai#10225
• Backfill an empty thinking field on current-turn tool calls in OpenAIChatModel's default 'auto' mode by @​dsfaccini in pydantic/pydantic-ai#10251
• Keep available_tool_names and active_capability_ids on run context copies inside Temporal activities and Render child tasks by @​dsfaccini in pydantic/pydantic-ai#10280
• Reconnect an xAI realtime session past max_duration when a reconnect policy is set by @​DouweM in pydantic/pydantic-ai#10056
• Await ProcessEventStream cleanup after early exit and cancellation by @​dsfaccini in pydantic/pydantic-ai#10341
• Count the request of a GPT-Live backend response that ends while the session closes by @​DouweM in pydantic/pydantic-ai#10084
• Warn when FallbackModel response handlers are skipped on a streamed request by @​DouweM in pydantic/pydantic-ai#10066
• Close the HTTP client of a model a run builds from a model name, and reuse one per name inside async with agent: by @​DouweM in pydantic/pydantic-ai#10067
• Make waits between continuation polls durable DBOS.sleep steps under DBOSDurability and DBOSAgent by @​DouweM in pydantic/pydantic-ai#10383
• Charge the partial response of an interrupted stream in SpendLimits by @​DouweM in pydantic/pydantic-ai#10069
• Stop WarnNearLimits from deleting user prompts that quote its [WarnNearLimits] marker by @​DouweM in pydantic/pydantic-ai#10391

New Contributors

• @​AndrewTilson made their first contribution in pydantic/pydantic-ai#9784
• @​miguel-flowstate made their first contribution in pydantic/pydantic-ai#8028
• @​jirikuncar made their first contribution in pydantic/pydantic-ai#10307
• @​michaeldunn9 made their first contribution in pydantic/pydantic-ai#10196

Full Changelog: pydantic/pydantic-ai@v2.56.0...v2.57.0

v2.56.0 (2026-10-13)

... (truncated)

Changelog

Sourced from pydantic-ai-slim's changelog.

---

description: "Pydantic AI upgrade guide and changelog: the breaking changes in each release, how to install V2, and the recommended path to migrate your code from V1."

Upgrade Guide

In September 2025, Pydantic AI reached V1 and committed to API stability: no changes that break your code until V2. V2 is now available, collecting the breaking and behavior changes that stability guarantee didn't allow. This guide is the canonical place to learn what's in V2, how to install it, and how to upgrade; for the guarantees behind these version numbers, see the Version Policy.

Deprecations

Functionality deprecated in a V2 release keeps working until V3, and using it raises a PydanticAIDeprecationWarning naming its replacement. Resolving these as they appear is the smooth path to the next major, the same way resolving V1's warnings was the smooth path to this one.

Deprecated in V2, to be removed in V3

• [RetryPromptPart][pydantic_ai.messages.RetryPromptPart] is deprecated in favor of the two parts it conflated: a retry that answers a tool call is that call's own [ToolReturnPart][pydantic_ai.messages.ToolReturnPart] with outcome='retried', and one that answers no tool call is a [RetryFeedbackPart][pydantic_ai.messages.RetryFeedbackPart]. The old part reached the model as bare user text in the second case, which the model couldn't tell from something a person wrote (#6404, #7799). Pydantic AI no longer emits it, and constructing one warns.
  • What keeps working: a 'retry-prompt' part in a serialized history loads as whichever of the two it always meant, and an instance your own code holds, including one handed back through [DeferredToolResults][pydantic_ai.tools.DeferredToolResults], is translated the same way before it reaches a model. The direct helpers send it in that new shape too. Calling [Model.request()][pydantic_ai.models.Model.request] or [Model.count_tokens()][pydantic_ai.models.Model.count_tokens] yourself skips that translation but still works: a tool-bound one goes out as that call's retried result, and a tool-less one as the user text it always rendered as. [sanitize_messages][pydantic_ai.messages.sanitize_messages] keeps client-returned retry feedback: it translates a tool-less one into the RetryFeedbackPart it always meant, keeps a 'validation_error' or 'model_retry' part as sent (it reaches the model fenced, in the user voice), and demotes a 'no_output' part, the one cause rendered in the system voice, to that same fenced, attributed user text, since a client can forge it; pass strip_system_prompts=False to keep a 'no_output' part as sent.
  • What you need to change: isinstance(part, RetryPromptPart) no longer matches, so match the two parts above instead. Each records why the retry happened, and which attempt it is against which limit, in a [RetryInfo][pydantic_ai.messages.RetryInfo] on its retry field, which tool spans also carry as pydantic_ai.tool.retry.* attributes. [ToolRetryError.tool_retry][pydantic_ai.exceptions.ToolRetryError] holds one of those two parts, so read tool_name off it only after checking for a ToolReturnPart.
  • What the model now sees: a tool retry carries the serialized validation errors or the ModelRetry message, with no N validation errors: header and no Fix the errors and try again. suffix. One that answers no call arrives in the voice its cause calls for: validation errors and a ModelRetry message in the user voice, inside a <validation_errors> or <retry_feedback> fence behind one line saying the application, not the user, is speaking, and the framework's fixed request for usable output in the system voice. On providers without a native tool error channel, a retried tool call's validation errors go in the {"error": ...} wrapper as a JSON array rather than as a string holding one, and Anthropic and Bedrock get them as one text block. Client-returned retry feedback is kept by [sanitize_messages][pydantic_ai.messages.sanitize_messages] and the UI adapters rather than stripped, and a 'no_output' part among it goes out as fenced user text rather than in the system voice. Retries in a history stored before upgrading are rendered the new way too, since rendering happens when each request goes out, so a conversation's first request after upgrading misses the provider's prompt cache from its first retry onward, once. A [decision model][pydantic_ai.models.decision.DecisionModel] judges a retried tool call as that call's tool_return, where it had a retry entry. On ag-ui-protocol below 0.1.11, [AGUIAdapter.dump_messages][pydantic_ai.ui.ag_ui.AGUIAdapter.dump_messages] now also warns on a run that retried its own output. See Retries.
  • Vercel AI dumps keep a request's part order: [VercelAIAdapter.dump_messages][pydantic_ai.ui.vercel_ai.VercelAIAdapter.dump_messages] now writes a ModelRequest as one UIMessage per run of same-role parts, in the order they were authored, instead of putting every system part first. This applies with no retries at all: a request holding an enqueued SystemPromptPart after its UserPromptPart now dumps as a user message followed by a system message, and positional message ids shift with it. The request's metadata rides on its last user message, or its last message when it has none.

Breaking Changes

Here's a filtered list of the breaking changes for each version to help you upgrade Pydantic AI.

v2.0.0 (2026-06-23)

The stable V2.0 release. There are no new breaking or behavior changes since the betas; the full breaking-change list and recommended upgrade path are in the v2.0.0b1 entry below. Install it with:

uv add pydantic-ai

v2.0.0b7 (2026-06-10)

The seventh V2 beta, forked from v1.107.0. There are no new V2 breaking or behavior changes since v2.0.0b6 below — everything in that entry applies unchanged — but this beta picks up the latest V1 release on top, which adds Claude Fable 5 / Mythos 5 model support and OpenRouter prompt caching (CachePoint), plus known_model_names() and Anthropic fixes; see the v1.107.0 release notes for the full list.

Install it the same way, pinning the exact pre-release version:

pip/uv-add "pydantic-ai==2.0.0b7"

For the full breaking-change list and the recommended upgrade path, see the v2.0.0b1 entry below; the only difference is that the latest V1 to upgrade through first is now v1.107.0.

v2.0.0b6 (2026-06-04)

The sixth V2 beta, forked from v1.106.0. There are no new V2 breaking or behavior changes since v2.0.0b5 below — everything in that entry applies unchanged — but this beta picks up the latest V1 release on top, which adds api_host/timeout configuration and base seed mapping for the xAI provider, plus streaming and data-URI handling fixes; see the v1.106.0 release notes for the full list.

Install it the same way, pinning the exact pre-release version:

... (truncated)

Commits

• 54a31ab Make /theme work in the clai2 web UI (#10277)
• c318927 Add code mode and speculation toggles to the clai2 web UI, with a read-only...
• 1f034ef Remove pre-release Agent.connect() and Responses WebSocket APIs (#10370)
• 27b41ca Stream token counts in the clai2 web UI while a turn runs (#10275)
• 253240f Show the Pydantic logo in the clai2 web UI (#10274)
• 3650d9e Use Pydantic brand colours in the clai2 web UI, in dark and light mode (#10...
• 9fd6f67 Group tool calls and center the new-session composer in the clai2 web UI (#...
• d16c4a6 Add the clai2 web UI: a sessions sidebar, streaming chat, tool cards, and a...
• b210940 Add an opt-in web plugin to clai2 that serves the session to a browser, w...
• 2c3303c Let clai2 plugins drive the prompt with PluginHost.send_input, `interrupt...
• Additional commits viewable in compare view

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[glebedel]

Redundant: #207 (pydantic-ai 2.57.0) resolves pydantic-ai-slim to the same 2.57.0 in uv.lock, so merging #207 delivers this bump. No open Dependabot alert on this package. Closed by s2d2 Security Autopilot for Guillaume. Reopen if this is wrong.