Enum Error 

#[non_exhaustive]
pub enum Error {
    Json(Error),
    Core(Error),
    Decode(String),
    Protocol(String),
    Patch {
        target: String,
        message: String,
    },
    State(Error),
    Run {
        message: String,
        code: Option<String>,
    },
    Http {
        status: u16,
        body: String,
    },
    Transport(Box<dyn Error + Send + Sync>),
    Config(String),
}

Everything that can go wrong while consuming an AG-UI stream.

The variant list is #[non_exhaustive]: new transports and validation rules are expected to add variants without a breaking release.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Json(Error)

A frame’s payload was not valid JSON, or not a valid Event.

Core(Error)

An error raised by the core protocol types.

Core’s protocol violations do not arrive here: they are flattened into Error::Protocol so that every rule a stream can break has one shape.

Decode(String)

The bytes were not well-formed text/event-stream.

Protocol(String)

The stream parsed, but broke a rule the protocol requires — a content event with no open message, a chunk with no id to attach to, events after the run finished.

Patch

An RFC 6902 patch could not be applied.

The target document is left exactly as it was: [json_patch::patch] rolls back the operations it had already applied, so a rejected patch never leaves half-mutated state behind.

Fields

target: String

What the patch targeted — "state", or "activity <message id>".

message: String

Why it was rejected, as reported by the patch engine.

State(Error)

The application state did not deserialize into the caller’s type.

The raw JSON state is still updated and correct; only the typed view is unavailable.

Run

The agent reported RUN_ERROR.

Fields

message: String

What went wrong, for a human.

code: Option<String>

The machine-readable code, when the agent sent one.

Http

The server answered with a status outside 2xx.

Fields

status: u16

The status code.

body: String

The response body, truncated to a readable length.

Transport(Box<dyn Error + Send + Sync>)

The transport failed — a connection reset, a DNS failure, a closed channel. Carries the underlying error.

Config(String)

A transport was configured with something it cannot use: an unparseable URL, an invalid header name.

Implementations

impl Error

pub fn transport(error: impl Error + Send + Sync + 'static) -> Self

Wraps any error as a Error::Transport.

Transports for exotic runtimes have their own error types; this is how they enter this crate’s error enum without a variant of their own.

Trait Implementations

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Error

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for Error

fn from(error: Error) -> Self

Converts to this type from the input type.