Pydantic AI
Pydantic AI adapter for Flyte.
Bring your own Pydantic AI Agent and run it durably on Flyte. The adapter
provides:
flyteplugins.agents.pydantic_ai.tool— turn a Flyte@env.taskinto a Pydantic AI tool that executes as a durable child action (own container/GPU, retries, caching). This is the sharedflyteplugins.agents.core.tool: Pydantic AI accepts plain (async) callables inAgent(tools=[...])and infers each tool’s schema from the callable’s signature, which the core wrapper preserves.flyteplugins.agents.pydantic_ai.run_agent— run the Pydantic AI agent loop inside your task and return the final answer.
Each tool call runs as a durable Flyte child action, and the run timeline is rendered into the Flyte task report.
Directory
Classes
| Class | Description |
|---|---|
FlyteModel |
Wrap a pydantic_ai.models.Model so each model turn is durable. |
Methods
| Method | Description |
|---|---|
run_agent() |
Run a Pydantic AI agent with the given tools and prompt; return the final text. |
run_agent_sync() |
Synchronous variant of run_agent for use in sync tasks; runs the async implementation on a dedicated event loop. |
tool() |
Wrap a Flyte @env.task as a plain async tool function — the generic default. |
Methods
run_agent()
def run_agent(
input: str,
tools: typing.Sequence[typing.Any] = (),
model: typing.Any = None,
instructions: str | None = None,
agent: typing.Any = None,
name: str = 'pydantic-ai-agent',
durable: bool = True,
observability: bool = True,
memory_key: str | None = None,
**run_kwargs: typing.Any,
) -> strRun a Pydantic AI agent with the given tools and prompt; return the final text.
Await this from an async task as await run_agent(...); from a sync task
use flyteplugins.agents.pydantic_ai.run_agent_sync instead.
Call this from inside an @env.task — that task is the durable parent.
Within it, each tool call runs as a durable Flyte child action. Give the
enclosing task retries=... for self-healing and report=True to see
the agent timeline.
Provide either a pre-built agent (with its tools already attached) or
tools + model to have one built for you — not both.
| Parameter | Type | Description |
|---|---|---|
input |
str |
The user prompt. |
tools |
typing.Sequence[typing.Any] |
tool-wrapped tools or bare @env.task templates. Used only when no agent is passed; the built agent attaches them natively. |
model |
typing.Any |
Model name (e.g. "openai:gpt-4o") or pydantic_ai Model instance for the built agent. Required on the builder path (no default is assumed — the adapter is provider agnostic); ignored when a pre-built agent is given. |
instructions |
str | None |
System prompt / instructions for the built agent. |
agent |
typing.Any |
A pre-built Pydantic AI Agent (tools already attached). Mutually exclusive with tools. |
name |
str |
Agent name (for debugging/observability). |
durable |
bool |
Record/replay each model turn via flyte.trace. On the builder path the inferred model is wrapped in FlyteModel; on the prebuilt- agent path durability is applied via agent.override(model=...) when the agent’s model can be obtained (best-effort otherwise). |
observability |
bool |
Render the run timeline into the Flyte task report. |
memory_key |
str | None |
Stable id (e.g. a user/thread id) for cross-run memory. When set, prior conversation history is loaded from a durable, keyed MemoryStore and passed as message_history=; after the run the full history is saved back, so a later run with the same key continues the conversation. Best-effort — a memory failure never breaks a run. |
**run_kwargs |
typing.Any |
Returns: The agent’s final output as a string.
run_agent_sync()
def run_agent_sync(
input: str,
tools: typing.Sequence[typing.Any] = (),
model: typing.Any = None,
instructions: str | None = None,
agent: typing.Any = None,
name: str = 'pydantic-ai-agent',
durable: bool = True,
observability: bool = True,
memory_key: str | None = None,
**run_kwargs: typing.Any,
) -> strSynchronous variant of run_agent for use in sync tasks; runs the async implementation on a dedicated event loop.
Run a Pydantic AI agent with the given tools and prompt; return the final text.
Await this from an async task as await run_agent(...); from a sync task
use flyteplugins.agents.pydantic_ai.run_agent_sync instead.
Call this from inside an @env.task — that task is the durable parent.
Within it, each tool call runs as a durable Flyte child action. Give the
enclosing task retries=... for self-healing and report=True to see
the agent timeline.
Provide either a pre-built agent (with its tools already attached) or
tools + model to have one built for you — not both.
| Parameter | Type | Description |
|---|---|---|
input |
str |
The user prompt. |
tools |
typing.Sequence[typing.Any] |
tool-wrapped tools or bare @env.task templates. Used only when no agent is passed; the built agent attaches them natively. |
model |
typing.Any |
Model name (e.g. "openai:gpt-4o") or pydantic_ai Model instance for the built agent. Required on the builder path (no default is assumed — the adapter is provider agnostic); ignored when a pre-built agent is given. |
instructions |
str | None |
System prompt / instructions for the built agent. |
agent |
typing.Any |
A pre-built Pydantic AI Agent (tools already attached). Mutually exclusive with tools. |
name |
str |
Agent name (for debugging/observability). |
durable |
bool |
Record/replay each model turn via flyte.trace. On the builder path the inferred model is wrapped in FlyteModel; on the prebuilt- agent path durability is applied via agent.override(model=...) when the agent’s model can be obtained (best-effort otherwise). |
observability |
bool |
Render the run timeline into the Flyte task report. |
memory_key |
str | None |
Stable id (e.g. a user/thread id) for cross-run memory. When set, prior conversation history is loaded from a durable, keyed MemoryStore and passed as message_history=; after the run the full history is saved back, so a later run with the same key continues the conversation. Best-effort — a memory failure never breaks a run. |
**run_kwargs |
typing.Any |
Returns
The agent’s final output as a string.
tool()
def tool(
func: AsyncFunctionTaskTemplate | typing.Callable | None = None,
name: str | None = None,
description: str | None = None,
) -> typing.CallableWrap a Flyte @env.task as a plain async tool function — the generic default.
For SDKs that accept plain Python callables as tools (deriving the schema from the
signature + docstring), this is the whole adapter tool: the returned
function carries the task’s signature (functools.wraps), dispatches to
task.aio() (so each call is a durable Flyte child action), exposes
__wrapped_task__, and wires the backing task to flyteplugins.agents.core.ToolTaskResolver.
Adapters whose SDK needs a native tool type (e.g. OpenAI’s
FunctionTool, Claude’s MCP SdkMcpTool) provide their own instead.
Also accepts any other callable — a plain function or an instance of a callable
class defining __call__ — and returns it usable as a tool as-is, since the
plain-callable SDKs derive the schema by inspecting the callable (a class instance
is inspected through its __call__). A name or description override is
applied to the callable best-effort.
Usable bare, parametrized or as a direct call:
@tool
@env.task
async def get_weather(city: str) -> str: ...| Parameter | Type | Description |
|---|---|---|
func |
AsyncFunctionTaskTemplate | typing.Callable | None |
|
name |
str | None |
|
description |
str | None |