Struct SisterError 

pub struct SisterError {
    pub code: ErrorCode,
    pub severity: Severity,
    pub message: String,
    pub context: Option<HashMap<String, Value>>,
    pub recoverable: bool,
    pub suggested_action: Option<SuggestedAction>,
}

Standard error type for ALL sisters — domain/business logic errors.

These errors occur AFTER a tool is found and invoked. In MCP, they become {isError: true} in the tool result, NOT JSON-RPC error responses.

Fields

code: ErrorCode

Error code (machine-readable)

severity: Severity

Severity level

message: String

Human-readable message (should be actionable for LLMs)

context: Option<HashMap<String, Value>>

Additional context (for debugging)

recoverable: bool

Is this recoverable?

suggested_action: Option<SuggestedAction>

Suggested action for recovery

Implementations

impl SisterError

pub fn new(code: ErrorCode, message: impl Into<String>) -> Self

Create a new error

pub fn with_context(self, key: impl Into<String>, value: impl Serialize) -> Self

Add context to the error

pub fn recoverable(self, recoverable: bool) -> Self

Set recoverable flag

pub fn with_suggestion(self, action: SuggestedAction) -> Self

Set suggested action

pub fn with_severity(self, severity: Severity) -> Self

Set severity

pub fn to_mcp_message(&self) -> String

Format as an MCP-friendly error message.

Includes what went wrong AND what to try instead, so the LLM can reason about recovery.

pub fn not_found(resource: impl Into<String>) -> Self

Not found error

pub fn invalid_input(message: impl Into<String>) -> Self

Invalid input error

pub fn permission_denied(message: impl Into<String>) -> Self

Permission denied error

pub fn internal(message: impl Into<String>) -> Self

Internal error (bug)

pub fn storage(message: impl Into<String>) -> Self

Storage error

pub fn context_not_found(context_id: impl Into<String>) -> Self

Context/session not found error

pub fn evidence_not_found(evidence_id: impl Into<String>) -> Self

Evidence not found error

Trait Implementations

impl Clone for SisterError

fn clone(&self) -> SisterError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SisterError

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

Formats the value using the given formatter.

impl Default for SisterError

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for SisterError

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for SisterError

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

Formats the value using the given formatter.

impl Error for SisterError

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 SisterError

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<Error> for SisterError

fn from(e: Error) -> Self

Converts to this type from the input type.

impl Serialize for SisterError

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.