Try this filter called `custom.lua`

````
function Meta(meta)
    meta["new"] = "new meta"
    return meta
end
````

Then 

````markdown
---
title: "Untitled"
format: gfm
filters: ["custom.lua"]
---

What is defined in the lua filter: "{{< meta new >}}"

````

If I run this with quarto 1.2 , I get the meta

````
Untitled
================

What is defined in the lua filter: “new meta”
````

If I run this with latest 1.3, I get an issue
````markdown
# Untitled

What is defined in the lua filter: “**?meta:new**”
````

Warning is being thrown
````
WARNING: Unknown meta key new specified in a metadata Shortcode.
````

Possibly a regression to look into. Unless we think this was not desired behavior. Though it seems expected to me to be able to expose custom meta defined in a filter through the meta shortcode. I know one extension who does not work anymore https://github.com/mcanouil/quarto-lua-env


cscheid
2023-03-30T09:11:57Z
cderv
bug triaged-to
v1.3
closed
Using meta shortcodes with value defined in Lua filters is not possible anymore 
https://github.com/quarto-dev/quarto-cli/issues/5031