Exceptions

Catch the narrowest exception that changes your recovery decision. All library transport and provider failures inherit from IGError; request and response validation uses pydantic.ValidationError.

from ig_trading_lib import AmbiguousExecutionError, ProviderRejectionError

try:
    confirmation = ig.operations.positions.create(request)
except AmbiguousExecutionError:
    # Reconcile account state. Replaying could duplicate the trade.
    raise
except ProviderRejectionError as error:
    print(error.error_code)

Failure hierarchy

Exception
├── PermissionError
│   └── LiveTradingPermissionError
└── RuntimeError
    └── IGError
        ├── AuthenticationError
        ├── AuthorizationError
        ├── RateLimitError
        ├── ProviderRejectionError
        ├── ResourceNotFoundError
        ├── TransportError
        ├── AmbiguousExecutionError
        ├── DealConfirmationError
        ├── StreamingSubscriptionError
        └── StreamingDataLossError

Recovery decisions

Exception	Meaning	Recovery
`AuthenticationError`	Credentials, session creation, or token refresh failed.	Correct credentials or re-authenticate before retrying.
`AuthorizationError`	The active account lacks permission.	Switch account or obtain entitlement.
`RateLimitError`	An IG allowance was exhausted.	Honour `retry_after_seconds` and use bounded backoff.
`ProviderRejectionError`	IG rejected a well-formed request.	Inspect `error_code`; correct input or account state.
`ResourceNotFoundError`	The resource is absent or inaccessible.	Verify the identifier and active account.
`TransportError`	A read did not complete because of network or timeout failure.	Retry only when the method page says the call is safe to repeat.
`AmbiguousExecutionError`	A mutation may have reached IG, but its outcome is unknown.	Reconcile account state; never replay automatically.
`DealConfirmationError`	IG accepted a mutation, but confirmation retrieval failed.	Retrieve confirmation using `deal_reference`; never replay the mutation.
`LiveTradingPermissionError`	A live mutation lacked an explicit `TradingPermit`.	Construct the client with a deliberate permit.
`StreamingSubscriptionError`	IG or Lightstreamer rejected the subscription.	Correct the item, field, mode, adapter, or entitlement.
`StreamingDataLossError`	IG reported lost updates or the local buffer overflowed.	Rebuild state from a fresh snapshot before resubscribing.
`pydantic.ValidationError`	Request construction or response validation failed.	Correct request fields or report provider schema drift.

Safe diagnostics

IGError provides status_code, error_code, request_id, operation_id, retry_after_seconds, and redacted details. Credential-like values are removed from retained provider details.

Bases: RuntimeError

Base error containing safe diagnostics for a failed IG request.

Bases: IGError

A mutation succeeded but its deal confirmation could not be retrieved.

Bases: PermissionError

Raised when a live mutation has not been explicitly permitted.