The following are example uses of the #get_web_data parser function (along with calls to #external_value and #for_external_table to display the information).

You can see these calls in action, with actual results, here.

IMDb

Retrieve data from IMDb, the Internet Movie Database.

{{#get_web_data:url=https://imdb-api.com/en/API/Title/IMDB_KEY/tt0055630
|format=json
|data=title=title,year=year,directors=directors,stars=stars}}
Info for ID '''tt0055630''':
* Name: {{#external_value:title}}
* Year: {{#external_value:year}}
* Director(s): {{#external_value:directors}}
* Actors: {{#external_value:stars}}

or simply

{{#get_external_data:url=https://imdb-api.com/en/API/Title/IMDB_KEY/tt0055630}}
Info for ID '''tt0055630''':
* Name: {{#external_value:title}}
* Year: {{#external_value:year}}
* Director(s): {{#external_value:directors}}
* Actors: {{#external_value:stars}}

You must also obtain an IMDb API key, and add the following to LocalSettings.php:

$wgExternalDataSources['imdb-api.com']['replacements'] = [
    'IMDB_KEY'=> '...your key here...'
];

NCBI taxonomy

Retrieve data from the National Center for Biotechnology Information.

{{#get_web_data:url=https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&rettype=fasta&retmode=xml&id=8371
|format=xml
|data=ScientificName=ScientificName,CommonName=CommonName,Division=Division}}
Information for taxon ID '''8371''':
* Scientific name: {{#external_value:ScientificName}}
* Common name: {{#external_value:CommonName}}
* Division: {{#external_value:Division}}

or simply (note the lower case in variable names):

{{#get_external_data:url=https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&rettype=fasta&retmode=xml&id=8371}}
Information for taxon ID '''8371''':
* Scientific name: {{#external_value:scientificname}}
* Common name: {{#external_value:commonname}}
* Division: {{#external_value:division}}

PubMed

Retrieve data from PubMed, run by the National Center for Biotechnology Information.

{{#get_web_data:url=https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=19782018&retmode=xml
|format=xml
|data=ArticleTitle=ArticleTitle,LastName=LastName,ForeName=ForeName,JournalTitle=Title,Year=Year,Volume=Volume}}
Information for PMID '''19782018''':
* Title: {{#external_value:ArticleTitle}}
* Name: {{#external_value:LastName}}, {{#external_value:ForeName}}
* Journal: {{#external_value:JournalTitle}}
* Year: {{#external_value:Year}}
* Volume: {{#external_value:Volume}}

Scopus

Retrieve data from Elsevier's Scopus database.

{{#get_web_data:
url=https://api.elsevier.com/content/search/scopus?query=DOI(10.1103/PhysRevA.20.1521)&apiKey=ELSEVIER_KEY
|format=json
|data=dc_title=dc:title,dc_creator=dc:creator,citedby-count=citedby-count}}
Information for '''10.1103/PhysRevA.20.1521''':
* Title: {{#external_value:dc_title}}
* Author: {{#external_value:dc_creator}}
* "Cited by" count: {{#external_value:citedby-count}}

You must also obtain an Elsevier API key, and add the following to LocalSettings.php:

$wgExternalDataSources['api.elsevier.com']['replacements'] = [
    'ELSEVIER_KEY'=> '...your key here...'
];

Wikidata - individual entry

SPARQL query:

SELECT ?item ?itemLabel ?symbol ?atomicNumber ( YEAR( ?discoveryDate ) AS ?discoveryYear ) ?discoverer ?discovererLabel
WHERE {
  VALUES ?item { wd:Q654 } .
  ?item wdt:P246 ?symbol .
  ?item wdt:P1086 ?atomicNumber .
  ?item wdt:P575 ?discoveryDate .
  ?item wdt:P61 ?discoverer
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Actual wikitext (which includes this query):

{{#get_web_data:url=https://query.wikidata.org/sparql?query={{urlencode: SELECT ?item ?itemLabel ?symbol ?atomicNumber ( YEAR( ?discoveryDate ) AS ?discoveryYear ) ?discoverer ?discovererLabel
WHERE {
  VALUES ?item { wd:Q654 } .
  ?item wdt:P246 ?symbol .
  ?item wdt:P1086 ?atomicNumber .
  ?item wdt:P575 ?discoveryDate .
  ?item wdt:P61 ?discoverer
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
} }}&format=json
|format=json
|use jsonpath
|data=itemLabel=$.results.bindings[0].itemLabel.value,
symbol=$.results.bindings[0].symbol.value,
atomicNumber=$.results.bindings[0].atomicNumber.value,
discoveryYear=$.results.bindings[0].discoveryYear.value,
discovererURL=$.results.bindings[*].discoverer.value,
discovererLabel=$.results.bindings[*].discovererLabel.value,
}}
Info for '''Q654''':
* Name: {{#external_value:itemLabel}}
* Symbol: {{#external_value:symbol}}
* Atomic number: {{#external_value:atomicNumber}}
* Year discovered: {{#external_value:discoveryYear}} 
* Discoverers: {{#for_external_table:[{{{discovererURL}}} {{{discovererLabel}}}], <nowiki />}}

Wikidata - full query

All paintings that depict a squirrel.

SPARQL query:

SELECT DISTINCT ?painting ?paintingLabel ?creator ?creatorLabel ( YEAR( ?inception ) as ?year ) ?genre ?genreLabel ( SUBSTR( ?str_image, 52 ) AS ?fileName )
WHERE
{
  ?painting wdt:P180 wd:Q9482 .
  ?painting wdt:P170 ?creator .
  ?painting wdt:P571 ?inception .
  ?painting wdt:P136 ?genre .
  ?painting wdt:P18 ?image .
  BIND (STR(?image) AS ?str_image)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY ?paintingLabel

Actual wikitext (which includes this query):

{{#get_web_data:url=https://query.wikidata.org/sparql?query={{urlencode: SELECT DISTINCT ?painting ?paintingLabel ?creator ?creatorLabel ( YEAR( ?inception ) as ?year ) ?genre ?genreLabel ( SUBSTR( ?str_image, 52 ) AS ?fileName )
WHERE
{
  ?painting wdt:P180 wd:Q9482 .
  ?painting wdt:P170 ?creator .
  ?painting wdt:P571 ?inception .
  ?painting wdt:P136 ?genre .
  ?painting wdt:P18 ?image .
  BIND (STR(?image) AS ?str_image)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY ?paintingLabel
}}&format=json
|format=json
|use jsonpath
|data=paintingURL=$.results.bindings[*].painting.value,
paintingLabel=$.results.bindings[*].paintingLabel.value,
creatorURL=$.results.bindings[*].creator.value,
creatorLabel=$.results.bindings[*].creatorLabel.value,
year=$.results.bindings[*].year.value,
genre=$.results.bindings[*].genreLabel.value,
fileName=$.results.bindings[*].fileName.value
}}

{| class="wikitable"
! Name
! Artist
! Year
! Genre
! Image {{#for_external_table:<nowiki/>
{{!}}-
{{!}} [{{{paintingURL}}} {{{paintingLabel}}}]
{{!}} [{{{creatorURL}}} {{{creatorLabel}}}]
{{!}} {{{year}}}
{{!}} {{{genre}}}
{{!}} [[File:{{{fileName}}}|80px]]
}}
|}