Enum McpErrorCode 

pub enum McpErrorCode {
    ToolNotFound,
    ToolTimeout,
    ToolPanicked,
    InvalidArguments,
    PermissionDenied,
    QuotaExceeded,
    NetworkBlocked,
    McpServerUnreachable,
    Internal,
    Unknown,
}

Closed vocabulary of error codes for Everruns’ own MCP tools/call execute path. Surfaces in McpExecuteError::code so LLM toolcallers can branch on a machine-readable value instead of regexing prose.

New variants are a spec change. SDKs should treat any value they don’t recognise as unknown (forward-compat) — serde’s #[serde(other)] catch-all enables that on the deserialize side.

Variants

ToolNotFound

Tool name doesn’t match any registered tool.

ToolTimeout

Tool timed out (server-imposed budget exceeded).

ToolPanicked

Tool panicked or hit an unrecoverable internal error.

InvalidArguments

Required argument missing or argument failed validation.

PermissionDenied

Caller is authenticated but not authorized for the requested action or org scope.

QuotaExceeded

Org/user quota or rate limit hit.

NetworkBlocked

Outbound network call blocked by egress policy.

McpServerUnreachable

Upstream MCP server unreachable or returned an error we couldn’t classify.

Internal

Catch-all for unclassified internal failures. Treat as transient only if retryable is also true.

Unknown

Forward-compat sentinel — SDKs see this when the server returns a code they don’t know yet.

Implementations

impl McpErrorCode

pub fn as_str(&self) -> &'static str

Stable wire string for this variant. Mirrors what serde emits so non-Rust SDKs and tests can match on the same value.

pub fn default_category(&self) -> McpErrorCategory

Default category for this code. Callers may override per-occurrence when context narrows the classification (e.g. an Internal with a known-transient root cause).

pub fn default_retryable(&self) -> bool

Default retryability for this code. Same override caveat as default_category.

Trait Implementations

impl Clone for McpErrorCode

fn clone(&self) -> McpErrorCode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for McpErrorCode

impl Debug for McpErrorCode

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for McpErrorCode

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for McpErrorCode

impl PartialEq for McpErrorCode

fn eq(&self, other: &McpErrorCode) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for McpErrorCode

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for McpErrorCode