How to use jq when the variable has reserved characters?

Question

I'm trying to get the following to work and it's not, help me please:

curl -s 'https://cryptofresh.com/api/asset/markets?asset=MKR' | jq .OPEN.BTC

The variable in question includes a period, I tried just about everything to escape the period && also tried surrounding it in quotes; no go ; this is the variable I'm looking to pull from (I ran jq without any filters, and truncated the output here to show what I need. Thanks in advance future problem solver!

curl -s 'https://cryptofresh.com/api/asset/markets?asset=MKR' | jq
....
 "OPEN.BTC": {
"volume24": 0.932166,
"price": 0.09995,
"updated": "2016-05-04T03:03:29.000Z"
},
....

Answer 1

When a key contains characters that are invalid for identifiers, you'll have to quote the name.

."OPEN.BTC"

Or for older versions of jq, use an index.

.["OPEN.BTC"]

Example

... | jq '."OPEN.BTC"'

Answer 2

Another answer didn't work for me but the comment written by @jeff-mercado worked for me. So, adding it as an answer here.

If your key has dots like "OPEN.BTC" then your jq command should be

curl -s 'https://cryptofresh.com/api/asset/markets?asset=MKR' | jq '."OPEN.BTC"'

Put the key first in double quotes and then escape the first dot by wrapping it using single quotes.