Skip to content

pydantic_ai.exceptions

ModelRetry

Bases: Exception

Exception raised when a tool function should be retried.

The agent will return the message to the model and ask it to try calling the function/tool again.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
22
23
24
25
26
27
28
29
30
31
32
33
class ModelRetry(Exception):
    """Exception raised when a tool function should be retried.

    The agent will return the message to the model and ask it to try calling the function/tool again.
    """

    message: str
    """The message to return to the model."""

    def __init__(self, message: str):
        self.message = message
        super().__init__(message)

message instance-attribute 

message: str = message

The message to return to the model.

UserError

Bases: RuntimeError

Error caused by a usage mistake by the application developer — You!

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
36
37
38
39
40
41
42
43
44
class UserError(RuntimeError):
    """Error caused by a usage mistake by the application developer — You!"""

    message: str
    """Description of the mistake."""

    def __init__(self, message: str):
        self.message = message
        super().__init__(message)

message instance-attribute 

message: str = message

Description of the mistake.

AgentRunError

Bases: RuntimeError

Base class for errors occurring during an agent run.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
47
48
49
50
51
52
53
54
55
56
57
58
class AgentRunError(RuntimeError):
    """Base class for errors occurring during an agent run."""

    message: str
    """The error message."""

    def __init__(self, message: str):
        self.message = message
        super().__init__(message)

    def __str__(self) -> str:
        return self.message

message instance-attribute 

message: str = message

The error message.

UsageLimitExceeded

Bases: AgentRunError

Error raised when a Model's usage exceeds the specified limits.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
61
62
class UsageLimitExceeded(AgentRunError):
    """Error raised when a Model's usage exceeds the specified limits."""

UnexpectedModelBehavior

Bases: AgentRunError

Error caused by unexpected Model behavior, e.g. an unexpected response code.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
class UnexpectedModelBehavior(AgentRunError):
    """Error caused by unexpected Model behavior, e.g. an unexpected response code."""

    message: str
    """Description of the unexpected behavior."""
    body: str | None
    """The body of the response, if available."""

    def __init__(self, message: str, body: str | None = None):
        self.message = message
        if body is None:
            self.body: str | None = None
        else:
            try:
                self.body = json.dumps(json.loads(body), indent=2)
            except ValueError:
                self.body = body
        super().__init__(message)

    def __str__(self) -> str:
        if self.body:
            return f'{self.message}, body:\n{self.body}'
        else:
            return self.message

message instance-attribute 

message: str = message

Description of the unexpected behavior.

body instance-attribute 

body: str | None = dumps(loads(body), indent=2)

The body of the response, if available.

ModelHTTPError

Bases: AgentRunError

Raised when an model provider response has a status code of 4xx or 5xx.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
class ModelHTTPError(AgentRunError):
    """Raised when an model provider response has a status code of 4xx or 5xx."""

    status_code: int
    """The HTTP status code returned by the API."""

    model_name: str
    """The name of the model associated with the error."""

    body: object | None
    """The body of the response, if available."""

    message: str
    """The error message with the status code and response body, if available."""

    def __init__(self, status_code: int, model_name: str, body: object | None = None):
        self.status_code = status_code
        self.model_name = model_name
        self.body = body
        message = f'status_code: {status_code}, model_name: {model_name}, body: {body}'
        super().__init__(message)

message instance-attribute 

message: str

The error message with the status code and response body, if available.

status_code instance-attribute 

status_code: int = status_code

The HTTP status code returned by the API.

model_name instance-attribute 

model_name: str = model_name

The name of the model associated with the error.

body instance-attribute 

body: object | None = body

The body of the response, if available.

FallbackExceptionGroup

Bases: ExceptionGroup

A group of exceptions that can be raised when all fallback models fail.

Source code in pydantic_ai_slim/pydantic_ai/exceptions.py 
114
115
class FallbackExceptionGroup(ExceptionGroup):
    """A group of exceptions that can be raised when all fallback models fail."""