> For the complete documentation index, see [llms.txt](https://docs.sign.global/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sign.global/for-builders/index-1.md).

# Writing Data

- [NPM SDK](https://docs.sign.global/for-builders/index-1/npm-sdk.md)
- [Installation](https://docs.sign.global/for-builders/index-1/npm-sdk/installation.md)
- [Usage](https://docs.sign.global/for-builders/index-1/npm-sdk/usage.md)
- [Schemas](https://docs.sign.global/for-builders/index-1/npm-sdk/usage/schemas.md)
- [Attestations](https://docs.sign.global/for-builders/index-1/npm-sdk/usage/attestations.md)
- [Examples](https://docs.sign.global/for-builders/index-1/npm-sdk/examples.md)
- [Changelog](https://docs.sign.global/for-builders/index-1/npm-sdk/changelog.md)
- [Smart Contract](https://docs.sign.global/for-builders/index-1/index.md)
- [EVM](https://docs.sign.global/for-builders/index-1/index/index.md)
- [Changelog](https://docs.sign.global/for-builders/index-1/index/index/changelog.md)
- [Interfaces](https://docs.sign.global/for-builders/index-1/index/index/index.md)
- [ISP](https://docs.sign.global/for-builders/index-1/index/index/index/isp.md): Version 1.0.0-beta18
- [ISPHook](https://docs.sign.global/for-builders/index-1/index/index/index/isphook.md): The hook is called for every attestation or revocation if the schema used specifies a hook.
- [IVersionable](https://docs.sign.global/for-builders/index-1/index/index/index/iversionable.md): This interface helps contracts to keep track of their versioning.
- [Data Models](https://docs.sign.global/for-builders/index-1/index/index/index-1.md)
- [Schema](https://docs.sign.global/for-builders/index-1/index/index/index-1/schema.md)
- [Attestation](https://docs.sign.global/for-builders/index-1/index/index/index-1/attestation.md)
- [DataLocation](https://docs.sign.global/for-builders/index-1/index/index/index-1/datalocation.md)