openapi: 3.0.3
info:
  title: Teller Accounts Institutions API
  description: Teller is a unified banking API providing real-time access to bank accounts, transactions, balances, identity data, and payment initiation across US financial institutions. Connect to thousands of banks and credit unions through a single integration. Teller uses mutual TLS (mTLS) for application authentication and access tokens obtained via Teller Connect for per-account authorization.
  version: 2020-10-12
  contact:
    name: Teller Developer Support
    url: https://teller.io/docs
  termsOfService: https://teller.io/legal/terms-of-service
servers:
- url: https://api.teller.io
  description: Teller Production API
tags:
- name: Institutions
  description: Supported financial institutions
paths:
  /institutions:
    get:
      operationId: listInstitutions
      summary: List Institutions
      description: Returns all supported financial institutions and the Teller products available for each. Does not require authentication.
      tags:
      - Institutions
      responses:
        '200':
          description: Institutions retrieved successfully
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Institution'
components:
  schemas:
    Institution:
      type: object
      description: A supported financial institution
      properties:
        id:
          type: string
          description: Teller identifier for the institution
        name:
          type: string
          description: Institution name
        products:
          type: array
          description: Teller products available for this institution
          items:
            type: string
            enum:
            - verify
            - balance
            - transactions
            - identity
  securitySchemes:
    BearerMtls:
      type: http
      scheme: bearer
      description: 'Access token obtained via Teller Connect when a user successfully enrolls their bank account. Must be used together with a Teller client certificate (mTLS). Encoded using HTTP Basic Auth scheme: ACCESS_TOKEN as username, empty password.'