> For the complete documentation index, see [llms.txt](https://docs.payments.thalescloud.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payments.thalescloud.io/classic-tokenization/api-reference/issuer-gateway-api.md).

# Issuer Gateway API

Use these resources to integrate your **issuer backend** with the Tokenization Service.

### Download the OpenAPI definitions

Use these OpenAPI (Swagger) definitions to generate client code and validate requests.

* [Outbound (Tokenization Service → issuer backend)](https://openapi.gitbook.com/o/fwy1mtbRONGA2YDKDBr0/spec/TSH-outbound.yaml)
* [Inbound (issuer backend → Tokenization Service)](https://openapi.gitbook.com/o/fwy1mtbRONGA2YDKDBr0/spec/TSH-inbound.yaml)

### Related documentation

* [API protocol](/classic-tokenization/get-started/api-basics/api-protocol.md)
* [Connectivity](/classic-tokenization/get-started/api-basics/connectivity.md)
* [Data encryption and security](/classic-tokenization/get-started/api-basics/data-encryption-and-security.md)
* [API guidelines](/classic-tokenization/get-started/api-basics/api-guidelines.md)

### Cobadged card API reference

If you support cobadged cards, use the dedicated reference:

* [API reference for cobadged cards](/classic-tokenization/api-reference-cobadged-cards/api-reference-cobadged-cards.md)


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