Teller API Integration Services USA | FintegrationFS
Integrate Teller for US bank linking, accounts, balances, transactions and webhooks with secure mTLS architecture and production support.
Teller API Integration Services for Secure US Bank Connectivity
Bank connectivity should feel calm to the customer, even when the underlying institution requires extra authentication or a connection needs attention. The product must know when data is fresh, when a user must reconnect and how to recover without losing context.
FintegrationFS provides Teller API integration services for US personal finance apps, lenders, accounting platforms and fintech products that need permissioned account, balance and transaction data. We build Teller Connect, certificate-based backend access, webhooks and operational recovery flows.
Teller API Use Cases
Bank account linking for personal finance products
Balance and account monitoring
Transaction feeds and financial analytics
Cash-flow and affordability views
Account ownership and account-detail workflows
Budgeting and spending tools
Bank-data support for lending or rental applications
Connectivity health and user reconnect journeys
Our Teller API Integration Services
Teller Connect web and mobile integration
Environment setup for sandbox, development and production
Client certificate and private-key management
Access-token exchange and encrypted storage
Accounts, balances, details and transactions integration
Webhook registration and event verification
Enrollment status and reconnect workflows
Transaction synchronization and duplicate handling
Security review, observability and support tools
Testing with real account structures in approved environments
Teller API Architecture With Mutual TLS
Your frontend launches Teller Connect with the products and environment required by the use case.
The user connects a financial institution and Teller Connect returns an access token.
The access token is sent to your backend and encrypted.
The backend calls Teller through HTTPS using the customer access token and the application client certificate.
Account and transaction data are normalized into the internal schema.
Webhooks notify the application about meaningful enrollment or transaction events.
The product displays data freshness and a recovery journey when an enrollment disconnects.
The certificate private key belongs only on protected backend infrastructure. Store it in a managed secret service, restrict access and rotate it according to the security policy.
Technical Code Example: Call Teller Accounts With MTLS
import fs from "node:fs";
import https from "node:https";
import axios from "axios";
const httpsAgent = new https.Agent({
cert: fs.readFileSync(process.env.TELLER_CERT_PATH),
key: fs.readFileSync(process.env.TELLER_KEY_PATH),
keepAlive: true,
minVersion: "TLSv1.2"
});
export async function getTellerAccounts(accessToken) {
const response = await axios.get("https://api.teller.io/accounts", {
httpsAgent,
auth: { username: accessToken, password: "" },
headers: {
"Teller-Version": "2019-07-01",
Accept: "application/json"
},
timeout: 10000
});
return response.data.map((account) => ({
providerAccountId: account.id,
name: account.name,
type: account.type,
subtype: account.subtype,
status: account.status
}));
} Webhooks and Enrollment Health
Teller can send events such as processed transactions or disconnected enrollments. A webhook should trigger a state refresh or background synchronization rather than directly making large changes without checking the current resource.
Deduplicate webhook IDs
Show last updated time in the product
Separate temporary connection issues from disconnected enrollments
Guide the user back through the correct reconnect experience
Do not hide stale data behind a healthy-looking screen
Monitor certificate expiry and failed mTLS requests
Why FintegrationFS for Teller API Integration Services?
Teller requires careful coordination between frontend connection flows, backend certificates, token storage and synchronization. We can build the complete service and connect it with analytics, lending, accounting or personal-finance features.
Plan Your Teller Integration
Tell us which account types, fields, refresh behavior and user journeys the product needs. We will design an integration that treats connectivity and recovery as first-class product features.
Frequently Asked Questions
How does Teller API authentication work?
Teller uses an end-user access token together with application client certificates. API requests require the correct certificate, creating a mutual TLS connection.
What is a Teller enrollment?
An enrollment represents a user connection to a financial institution. It may contain multiple financial accounts.
Does Teller provide multiple integration environments?
Teller documents sandbox, development and production environments for different stages of testing and launch.
Why should we monitor enrollment status?
A connected institution can require user action or become disconnected. Monitoring prevents the application from presenting stale data as current.
Does FintegrationFS sell Teller access?
No. Customers obtain access directly from Teller. FintegrationFS provides independent implementation and support.
* FintegrationFS is an independent integration services provider. All product names, logos, and brands are the property of their respective owners, used for identification only.