# NMI Authentication API

**Canonical:** https://apis.io/apis/nmi/nmi-authentication-api/  
**Provider:** NMI — https://apis.io/providers/nmi/  
**Base URL:** https://secure.networkmerchants.com  
**Documentation:** https://secure.networkmerchants.com/gw/merchants/resources/integration/integration_portal.php

NMI Authentication API is one of 28 APIs that [NMI](https://apis.io/providers/nmi/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. This API exposes 18 JSON Schema definitions. Tagged areas include Authentication. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, and 18 JSON Schemas.

The Authorization endpoint allows clients to securely authenticate and obtain an access token for making requests to the API.

## Operations (1)

| Method | Path | Summary |
|---|---|---|
| POST | `/oauth/token` | Request an Access Token |

## Machine-readable artifacts (21)

- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/openapi/nmi-authentication-api-openapi.yml
- **Documentation** — https://docs.nmi.com/docs
- **Sandbox** — https://docs.nmi.com/docs/sandbox-testing
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-conversation-amount-input-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-conversation-expiration-date-input-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-conversation-instructions-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-nmi-record-id-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-conversation-id-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-conversation-customer-phone-with-dashes-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-response-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-credit-card-payment-in-full-partial-request-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-credit-card-sale-request-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-achcredit-request-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-achsale-request-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-credit-card-capture-request-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-package-fields-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-application-document-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-package-collection-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-full-application-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-subscription-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/nmi/refs/heads/main/json-schema/nmi-pagination-schema.json

## Other NMI APIs (12)

- [NMI Three Step Redirect API](https://apis.io/apis/nmi/nmi-three-step-redirect-api/)
- [NMI Customer-Present Cloud API](https://apis.io/apis/nmi/nmi-customer-present-cloud-api/)
- [NMI Webhook Events API](https://apis.io/apis/nmi/nmi-payments-api/)
- [NMI Affiliates API](https://apis.io/apis/nmi/nmi-affiliates-api/)
- [NMI Apple Pay API](https://apis.io/apis/nmi/nmi-apple-pay-api/)
- [NMI Applications API](https://apis.io/apis/nmi/nmi-applications-api/)
- [NMI Authvia TXT2PAY API](https://apis.io/apis/nmi/nmi-authvia-txt2pay-api/)
- [NMI Billing & Commission API](https://apis.io/apis/nmi/nmi-billing-commission-api/)
- [NMI Component Sessions API](https://apis.io/apis/nmi/nmi-component-sessions-api/)
- [NMI Customers API](https://apis.io/apis/nmi/nmi-customers-api/)
- [NMI Data and Transaction Reporting API](https://apis.io/apis/nmi/nmi-data-and-transaction-reporting-api/)
- [NMI Devices API](https://apis.io/apis/nmi/nmi-devices-api/)

## Tags

Authentication

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/nmi/nmi-authentication-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/nmi/.