Enum AdapterError 

pub enum AdapterError {
    Auth {
        reason: AuthFailureReason,
    },
    RateLimited {
        retry_after_ms: u64,
    },
    Upstream {
        inner: UpstreamErrorKind,
    },
    Validation {
        field: String,
        message: String,
    },
    SizeCapExceeded {
        requested: f64,
        cap: f64,
    },
    NotEnabled {
        tool: String,
        flag: String,
    },
    Internal {
        reason: String,
    },
}

Errors emitted by the adapter and surfaced over the MCP wire.

Every fallible path in the adapter ultimately produces one of these variants. The serde representation uses an internally tagged "kind" discriminant (#[serde(tag = "kind")]) so the JSON shape is stable and discoverable by an LLM client.

Variants are intentionally closed — _ arms on AdapterError are forbidden by the project’s coding rules. Add a new variant when a structurally new error kind appears.

Variants

Auth

Authentication / authorization failure.

Fields

reason: AuthFailureReason

Why authentication failed.

RateLimited

Rate-limit signal from upstream. The MCP layer never silently retries (ADR-0008); it surfaces the hint so the LLM can decide.

Fields

retry_after_ms: u64

Suggested wait before re-issuing the call. Zero means “unknown — back off and retry”.

Upstream

Upstream returned a structured error that is neither auth nor rate-limit shaped.

Fields

inner: UpstreamErrorKind

Where the error came from and the structured payload.

Validation

Input failed validation at the MCP boundary before any upstream call was made.

Fields

field: String

Field name as it appears in the tool’s input schema.

message: String

Human-readable explanation; safe to surface to an LLM.

SizeCapExceeded

--max-order-usd cap exceeded. Trading-class concern; surfaced here so all errors flow through one type.

Fields

requested: f64

Requested notional in USD.

cap: f64

Configured cap in USD.

NotEnabled

A tool exists but is not enabled in this binary’s configuration (e.g. Trading without --allow-trading).

Fields

tool: String

Tool name as listed in the registry. Construct via AdapterError::not_enabled from a &'static str literal.

flag: String

CLI flag that would enable it.

Internal

Last-resort variant for failures that should not propagate detail across the MCP boundary (e.g. an upstream payload that might leak a signature). The original error is logged at DEBUG with the redaction filter active.

Fields

reason: String

Pre-vetted reason string. Construct via AdapterError::internal from a &'static str literal — never user-controlled content.

Implementations

impl AdapterError

pub fn validation(field: impl Into<String>, message: impl Into<String>) -> Self

Convenience constructor for AdapterError::Validation.

pub fn rate_limited(retry_after: Duration) -> Self

Convenience constructor for AdapterError::RateLimited from a Duration.

impl AdapterError

pub fn not_enabled(tool: &'static str, flag: &'static str) -> Self

Convenience constructor for AdapterError::NotEnabled.

pub fn internal(reason: &'static str) -> Self

Convenience constructor for AdapterError::Internal.

Trait Implementations

impl Debug for AdapterError

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AdapterError

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for AdapterError

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

Formats the value using the given formatter.

impl Error for AdapterError

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<DeribitFixError> for AdapterError

Available on crate feature fix only.

fn from(err: DeribitFixError) -> Self

Converts to this type from the input type.

impl From<Error> for AdapterError

fn from(_err: Error) -> Self

Converts to this type from the input type.

impl From<HttpError> for AdapterError

fn from(err: HttpError) -> Self

Converts to this type from the input type.

impl From<WebSocketError> for AdapterError

fn from(err: WebSocketError) -> Self

Converts to this type from the input type.

impl PartialEq for AdapterError

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for AdapterError

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 AdapterError