Error Hierarchy
All SDK errors extend from XpozError. Import them from the package:
import {
XpozError,
AuthenticationError,
XpozConnectionError,
OperationTimeoutError,
OperationFailedError,
OperationCancelledError,
} from "@xpoz/xpoz";
| Error Class | When It’s Thrown |
|---|
XpozError | Base class for all Xpoz errors |
AuthenticationError | Invalid or missing access key |
XpozConnectionError | Cannot connect to the MCP server |
OperationTimeoutError | Operation exceeded the configured timeout |
OperationFailedError | Operation failed server-side |
OperationCancelledError | Operation was cancelled |
Catching Errors
Use instanceof checks to handle specific error types. Always catch more specific errors before the base XpozError:
try {
const user = await client.twitter.getUser("nonexistent_user_12345");
} catch (e) {
if (e instanceof OperationFailedError) {
console.log(`Operation ${e.operationId} failed: ${e.operationError}`);
} else if (e instanceof OperationTimeoutError) {
console.log(`Timed out after ${Math.round(e.elapsedMs / 1000)}s`);
} else if (e instanceof AuthenticationError) {
console.log("Invalid access key");
} else if (e instanceof XpozConnectionError) {
console.log("Cannot connect to MCP server");
} else if (e instanceof XpozError) {
console.log(`Xpoz error: ${e.message}`);
}
}
Error Details
AuthenticationError
Thrown when the access key is invalid, expired, or missing.
try {
const client = new XpozClient({ apiKey: "invalid-key" });
await client.connect();
await client.twitter.getUser("elonmusk");
} catch (e) {
if (e instanceof AuthenticationError) {
console.log(e.message); // "Invalid access key" or similar
}
}
OperationTimeoutError
Thrown when an operation exceeds the configured timeout (default: 300,000ms / 5 minutes). The error includes the elapsed time.
try {
const results = await client.twitter.searchPosts("very broad query");
} catch (e) {
if (e instanceof OperationTimeoutError) {
console.log(`Timed out after ${Math.round(e.elapsedMs / 1000)}s`);
// Consider narrowing your query or increasing timeoutMs
}
}
If you frequently hit timeouts, increase the timeout when creating the client: new XpozClient({ timeoutMs: 600_000 }). You can also narrow your queries with date filters, field selection, or more specific search terms.
OperationFailedError
Thrown when an operation completes but with an error status. Includes the operationId and error details.
try {
const results = await client.twitter.searchPosts("query");
} catch (e) {
if (e instanceof OperationFailedError) {
console.log(`Operation: ${e.operationId}`);
console.log(`Error: ${e.operationError}`);
}
}
OperationCancelledError
Thrown when an operation is cancelled, typically due to server-side resource management.
try {
const results = await client.twitter.searchPosts("query");
} catch (e) {
if (e instanceof OperationCancelledError) {
console.log(`Operation ${e.operationId} was cancelled`);
}
}
Practical Pattern
A robust wrapper that handles all error cases:
import {
XpozClient,
XpozError,
AuthenticationError,
OperationTimeoutError,
OperationFailedError,
OperationCancelledError,
} from "@xpoz/xpoz";
async function searchWithRetry(client: XpozClient, query: string): Promise<void> {
try {
const results = await client.twitter.searchPosts(query, {
startDate: "2025-01-01",
});
console.log(`Found ${results.pagination.totalRows} results`);
for (const post of results.data) {
console.log(`${post.authorUsername}: ${post.text}`);
}
} catch (e) {
if (e instanceof AuthenticationError) {
throw e; // Cannot recover — propagate to caller
} else if (e instanceof OperationTimeoutError) {
console.log("Query timed out — try narrowing the date range or query");
} else if (e instanceof OperationFailedError) {
console.log(`Server error: ${e.operationError}`);
} else if (e instanceof OperationCancelledError) {
console.log("Operation cancelled — retrying may help");
} else if (e instanceof XpozError) {
console.log(`Unexpected Xpoz error: ${e.message}`);
} else {
throw e; // Not an Xpoz error — rethrow
}
}
}
For the equivalent error handling patterns in Python, see Python SDK Error Handling. The Python SDK uses try/except with the same error hierarchy but Python exception classes (OperationFailedError, OperationTimeoutError, etc.). 
