#IBM/Lotus Notes @Formula, 24 23 bytes

Computed value in a Notes field.

"{\"\":"+@Text(@Pi)+"}"

Outputs:

{"":3.14159265358979}

Nothing clever - just uses the shortest possible function that outputs a number then converts it to text for display.

IBM/Lotus Notes @Formula, 24 23 bytes

Computed value in a Notes field.

"{\"\":"+@Text(@Pi)+"}"

Outputs:

{"":3.14159265358979}

Nothing clever - just uses the shortest possible function that outputs a number then converts it to text for display.

#IBM/Lotus Notes @Formula, 24 bytes

Computed value in a Notes field.

"{\"a\":"+@Text(@Pi)+"}"

Outputs:

{"a":3.14159265358979}

Nothing clever - just uses the shortest possible function that outputs a number then converts it to text for display.

Interestingly enough missing out the "a" and just using

"{\"\":"+@Text(@Pi)+"}"

to give

{"":3.14159265358979}

also passes the JSONLint validator and saves 1 byte but although I guess that proves that strictly it's valid JSON it's also pretty useless JSON so I'll just keep it as a side observation.

#IBM/Lotus Notes @Formula, 24 23 bytes

Computed value in a Notes field.

"{\"\":"+@Text(@Pi)+"}"

Outputs:

{"":3.14159265358979}

Nothing clever - just uses the shortest possible function that outputs a number then converts it to text for display.