persona sdk patterns | sed 's/\b(.)/\u\1/g'
Overview
Singleton API client, typed verification results, pagination through inquiries, error classification.
Prerequisites
- Completed
persona-install-authsetup - Valid Persona API key (sandbox or production)
Instructions
Step 1: Typed API Client Wrapper
import axios, { AxiosInstance, AxiosError } from 'axios';
interface PersonaConfig {
apiKey: string;
version?: string;
baseURL?: string;
}
class PersonaClient {
private http: AxiosInstance;
constructor(config: PersonaConfig) {
this.http = axios.create({
baseURL: config.baseURL || 'https://withpersona.com/api/v1',
headers: {
'Authorization': `Bearer ${config.apiKey}`,
'Persona-Version': config.version || '2023-01-05',
'Content-Type': 'application/json',
},
});
}
async createInquiry(templateId: string, referenceId: string, fields?: Record<string, any>) {
const { data } = await this.http.post('/inquiries', {
data: { attributes: { 'inquiry-template-id': templateId, 'reference-id': referenceId, fields } },
});
return data.data;
}
async getInquiry(inquiryId: string) {
const { data } = await this.http.get(`/inquiries/${inquiryId}`);
return data.data;
}
async listInquiries(params: { referenceId?: string; status?: string; pageSize?: number } = {}) {
const { data } = await this.http.get('/inquiries', {
params: {
'filter[reference-id]': params.referenceId,
'filter[status]': params.status,
'page[size]': params.pageSize || 25,
},
});
return data.data;
}
async getVerification(verificationId: string) {
const { data } = await this.http.get(`/verifications/${verificationId}`);
return data.data;
}
}
// Singleton
let _client: PersonaClient | null = null;
export function getPersonaClient(): PersonaClient {
if (!_client) {
_client = new PersonaClient({ apiKey: process.env.PERSONA_API_KEY! });
}
return _client;
}
Step 2: Error Classification
function classifyPersonaError(error: AxiosError): { retryable: boolean; message: string } {
const status = error.response?.status;
if (status === 429) return { retryable: true, message: 'Rate limited' };
if (status && status >= 500) return { retryable: true, message: 'Server error' };
if (status === 401) return { retryable: false, message: 'Invalid API key' };
if (status === 422) return { retryable: false, message: 'Invalid request' };
return { retryable: false, message: error.message };
}
Output
- Typed Persona API client with inquiry and verification methods
- Singleton pattern for reuse
- Error classification for retry decisions
- Paginated inquiry listing
Error Handling
| Pattern | Use Case | Benefit | |---------|----------|---------| | Singleton | All API calls | One client, consistent headers | | Error classifier | Retry decisions | Only retry 429/5xx | | Typed responses | Data access | Autocomplete, type safety |
Resources
Next Steps
Apply in persona-core-workflow-a for real KYC flows.