# Infrastructure

# Base library update

In order to avoid the unknown impact of new libraries on online Weixin Mini Program, WeChat clients are released with libraries that carry the previous stable version **** .

After the new version client is released, the new version repository is greyed through the background. The greying time is generally 12 to 24 hours. After the greying is finished, the new release repository will not be available on the user device.

In the case of WeChat 6.5.8, the client was released with the 1.1.1 foundation library (the full stable version on 6.5.7), and after the release of 6.5.8, we went through the background to grey the 1.2.0 foundation library.

See the base library version distribution

# The relationship between the base library and the client

The capabilities of Weixin Mini Program require a WeChat client to support, and each base library can only run on the corresponding client version, and a high-level base library cannot be compatible with a low-level WeChat client.Usually:

  • A 1 (major) or 2 (minor) bit version number update usually requires relying on a newer version of the client, such as a base library v2.1.3 running on a v6.7.7 client, or a base Library v2.2.0 requiring a v6.9.7 client.
  • The 3rd (patch) bit version number update generally does not rely on client updates; for example, the base library v2.1.0 ~ v2.1.3 is running on the v6.6.7 client, and the new release covers the old version.

For compatibility methods for base libraries, see the section " Compatibility Handling ."