UPDATE, 12/7/18 18:00 UTC: Four hours after announcing the list, Coinbase Pro said it was launching support for Civic, District0x, Loom Network and Decentraland's tokens. Its order books will remain in transfer-only mode for 48 hours, with customers able to deposit, but not withdraw, any of the tokens.

After adding support for several new tokens over the past months, Coinbase has revealed more than 30 crypto assets it is considering for listing.

However, the San-Francisco-based exchange is not adding the 31 tokens to its platform just yet, but rather, is "continuing to explore the addition" of the assets, according to a blog post published Friday. The tokens included in the list range from ERC-20 tokens to independent projects.

"Over time, we intend to offer our customers access to greater than 90 percent of all compliant digital assets by market cap," the post said.

There are some caveats however. The post explained that the process to add new tokens requires "significant exploratory work" on both technical and legal compliance aspects, and the firm cannot guarantee that all the named tokens will actually be added.

The post went on to say:

The exchange warned its customers that some may see assets appear on public-facing APIs and other services before they are officially listed, but should that happen, Coinbase "cannot commit to when or whether these assets will become available."

Coinbase customers were able to see hints of tokens being added previously as well. Bots were able to take advantage of the exchange's API to begin trading 0x a few minutes before it was officially listed.

In another example, users reported seeing zcash appear on the Coinbase Wallet app before it was officially announced.

Editor's note: This article has been updated.

Brian Armstrong onstage at Techcrunch Disrupt London in 2014