API Docs: v1
For an introduction to the MetaCPAN API (Application Program Interface) which requires no previous knowledge of MetaCPAN or ElasticSearch, see the slides for "Abusing MetaCPAN for Fun and Profit" or watch the actual talk. This API lets you programmatically access MetaCPAN from your own applications.
There is also a repository of examples you can play with to get up and running in a hurry. Rather than editing this wiki page, please send pull requests for the metacpan-examples repository. If you'd rather edit the wiki, please do, but sending the code pull requests is probably the most helpful way to approach this.
All of these URLs can be tested using the MetaCPAN Explorer
To learn more about the ElasticSearch query DSL (Domain-Specific Language) check out Clinton Gormley's Terms of Endearment - ES Query DSL Explained slides.
The query syntax is explained on ElasticSearch's reference page. You can also check out this getting started tutorial about Elasticsearch reference page.
Being polite
Currently, the only rules around using the API are to "be polite". We have enforced an upper limit of a size of 5,000 on search requests. If you need to fetch more than 5,000 items, you should look at using the scrolling API. Search this page for "scroll" to get an example using Search::Elasticsearch or see the Elasticsearch scroll docs if you are connecting in some other way.
You can certainly scroll if you are fetching less than 5,000 items. You might want to do this if you are expecting a large data set, but will still need to run many requests to get all of the required data.
Be aware that when you scroll, your docs will come back unsorted, as noted in the ElasticSearch scan documentation.
Identifying Yourself
Part of being polite is letting us know who you are and how to reach you. This is not mandatory, but please do consider adding your app to the API-Consumers page.
Available fields
Available fields can be found by accessing the corresponding _mapping endpoint.
- /author/_mapping - explore
- /distribution/_mapping - explore
- /favorite/_mapping - explore
- /file/_mapping - explore
- /module/_mapping - explore
- /rating/_mapping - explore
- /release/_mapping - explore
Field documentation
Fields are documented in the API codebase: https://github.com/metacpan/metacpan-api/tree/master/lib/MetaCPAN/Document Check the Pod for discussion of what the various fields represent. Be sure to have a look at https://github.com/metacpan/metacpan-api/blob/master/lib/MetaCPAN/Document/File.pm in particular as results for /module are really a thin wrapper around the file type.
Search without constraints
Performing a search without any constraints is an easy way to get sample data
- /author/_search
- /distribution/_search
- /favorite/_search
- /file/_search
- /rating/_search
- /release/_search
Joins
ElasticSearch itself doesn't support joining data across multiple types. The API server can, however, handle a join query parameter if the underlying type was set up accordingly. Browse https://github.com/metacpan/metacpan-api/blob/master/lib/MetaCPAN/Server/Controller/ to see all join conditions. Here are some examples.
Joins on documents:
- /author/PERLER?join=favorite
- /author/PERLER?join=favorite&join=release
- /release/Moose?join=author
- /module/Moose?join=release
Joins on search results is work in progress.
Restricting the joined results can be done by using the boolean "should" occurrence type:
curl -XPOST https://fastapi.metacpan.org/v1/author/PERLER?join=release -d '
{
"query": {
"bool": {
"should": [{
"term": {
"release.status": "latest"
}
}]
}
}
}'JSONP
Simply add a callback query parameter with the name of your callback, and you'll get a JSONP response.
GET convenience URLs
You should be able to run most POST queries, but very few GET urls are currently exposed. However, these convenience endpoints can get you started. You should note that they behave differently than the POST queries in that they will return to you the latest version of a module or dist and they remove a lot of the verbose ElasticSearch data which wraps results.
/distribution/{distribution}
The /distribution endpoint accepts the name of a distribution (e.g. /distribution/Moose), which returns information about the distribution which is not specific to a version (like RT bug counts).
/download_url/{module}
The /download_url endpoint exists specifically for the cpanm client. It takes a module name with an optional version (or range of versions) and an optional dev flag (for development releases) and returns a download_url as well as some other helpful info.
Obviously anyone can use this endpoint, but we'll only consider changes to this endpoint after considering how cpanm might be affected.
- https://fastapi.metacpan.org/v1/download_url/HTTP::Tiny
- https://fastapi.metacpan.org/v1/download_url/Moose?version===0.01
- https://fastapi.metacpan.org/v1/download_url/Moose?version=!=0.01
- https://fastapi.metacpan.org/v1/download_url/Moose?version=<=0.02
- https://fastapi.metacpan.org/v1/download_url/Try::Tiny?version=>0.21,<0.27,!=0.24
- https://fastapi.metacpan.org/v1/download_url/Try::Tiny?version=>0.21,<0.27&dev=1
- https://fastapi.metacpan.org/v1/download_url/Try::Tiny?version=>0.21,<0.27,!=0.26&dev=1
/release/{distribution}
/release/{author}/{release}
The /release endpoint accepts either the name of a distribution (e.g. /release/Moose), which returns the most recent release of the distribution. Or provide the full path which consists of its author and the name of the release (e.g. /release/DOY/Moose-2.0001).
/author/{author}
author refers to the pauseid of the author. It must be uppercased (e.g. /author/DOY).
/module/{module}
Returns the corresponding file of the latest version of the module. Considering that Moose-2.0001 is the latest release, the result of /module/Moose is the same as /file/DOY/Moose-2.0001/lib/Moose.pm.
/pod/{module}
/pod/{author}/{release}/{path}
Returns the POD of the given module. You can change the output format by either passing a content-type query parameter (e.g. /pod/Moose?content-type=text/plain or by adding an Accept header to the HTTP request. Valid content types are:
- text/html (default)
- text/plain
- text/x-pod
- text/x-markdown
/source/{module}
Returns the full source of the latest, authorized version of the given
module.
GET Searches
Names of latest releases by OALDERS:
5,000 CPAN Authors:
https://fastapi.metacpan.org/v1/author/_search?q=*&size=5000
All CPAN Authors Who Have Provided Twitter IDs:
https://fastapi.metacpan.org/v1/author/_search?q=profile.name:twitter
All CPAN Authors Who Have Updated MetaCPAN Profiles:
https://fastapi.metacpan.org/v1/author/_search?q=updated:*&sort=updated:desc
First 100 distributions which SZABGAB has given a ++:
The 100 most recent releases ( similar to https://metacpan.org/recent )
Number of ++'es that DOY's dists have received:
https://fastapi.metacpan.org/v1/favorite/_search?q=author:DOY&size=0
List of users who have ++'ed DOY's dists and the dists they have ++'ed:
https://fastapi.metacpan.org/v1/favorite/_search?q=author:DOY&fields=user,distribution
Last 50 dists to get a ++:
The Changes file of the Test-Simple distribution:
https://fastapi.metacpan.org/v1/changes/Test-Simple
Querying the API with MetaCPAN::Client
Perhaps the easiest way to get started using MetaCPAN is with MetaCPAN::Client.
You can get started with this example script to fetch author data.
Querying the API with Search::Elasticsearch
The API server at fastapi.metacpan.org is a wrapper around an Elasticsearch instance. It adds support for the convenient GET URLs, handles authentication and does some access control. Therefore you can use the powerful API of Search::Elasticsearch to query MetaCPAN.
NOTE: The cxn_pool => 'Static::NoPing' is important because of the HTTP proxy we have in front of Elasticsearch.
You can get started with this example script to fetch author data.
POST Searches
Please feel free to add queries here as you use them in your own work, so that others can learn from you.
Downstream Dependencies
This query returns a list of all releases which list MooseX::NonMoose as a dependency.
curl -XPOST https://fastapi.metacpan.org/v1/release/_search -d '{
"size": 5000,
"fields": [ "distribution" ],
"filter": {
"and": [
{ "term": { "dependency.module": "MooseX::NonMoose" } },
{ "term": {"maturity": "released"} },
{ "term": {"status": "latest"} }
]
}
}'Note it is also possible to use these queries in GET requests (useful for cross-domain JSONP requests) by appropriately encoding the JSON query into the source parameter of the URL. For example the query above would become:
curl 'https://fastapi.metacpan.org/v1/release/_search?source=%7B%22query%22%3A%7B%22match_all%22%3A%7B%7D%7D%2C%22size%22%3A5000%2C%22fields%22%3A%5B%22distribution%22%5D%2C%22filter%22%3A%7B%22and%22%3A%5B%7B%22term%22%3A%7B%22release.dependency.module%22%3A%22MooseX%3A%3ANonMoose%22%7D%7D%2C%7B%22term%22%3A%7B%22release.maturity%22%3A%22released%22%7D%7D%2C%7B%22term%22%3A%7B%22release.status%22%3A%22latest%22%7D%7D%5D%7D%7D'
The size of the CPAN unpacked
Get license types of all releases in an arbitrary time span:
curl -XPOST https://fastapi.metacpan.org/v1/release/_search?size=100 -d '{
"query": {
"range" : {
"date" : {
"gte" : "2010-06-05T00:00:00",
"lte" : "2011-06-05T00:00:00"
}
}
},
"fields": ["license", "name", "distribution", "date", "version_numified"]
}'Aggregate by license:
curl -XPOST https://fastapi.metacpan.org/v1/release/_search -d '{
"query": {
"match_all": {}
},
"aggs": {
"license": {
"terms": {
"field": "license"
}
}
},
"size": 0
}'Most used file names in the root directory of releases:
curl -XPOST https://fastapi.metacpan.org/v1/file/_search -d '{
"query": { "filtered":{"query":{"match_all":{}},"filter":{"term":{"level":0}}}
},
"aggs": {
"license": {
"terms": {
"size":100,
"field":"name"
} } },
"size":0
}'Find all releases that contain a particular version of a module:
curl -XPOST https://fastapi.metacpan.org/v1/file/_search -d '{
"query": { "filtered":{
"query":{"match_all":{}},
"filter":{"and":[
{"term":{"module.name":"DBI::Profile"}},
{"term":{"module.version":"2.014123"}}
]}
}},
"fields":["release"]
}'Find all authors with Twitter in their profiles
Get a leaderboard of ++'ed distributions
Get a leaderboard of Authors with Most Uploads
Search for a release by name
Get the latest version numbers of your favorite modules
Note that "size" should be the number of distributions you are looking for.
lynx --dump --post_data https://fastapi.metacpan.org/v1/release/_search <<EOL
{
"query" : { "terms" : { "distribution" : [
"Mojolicious",
"MetaCPAN-API",
"DBIx-Class"
] } },
"filter" : { "term" : { "status" : "latest" } },
"fields" : [ "distribution", "version" ],
"size" : 3
}
EOLGet a list of all files where the directory is false and the path is blank
curl -XPOST https://fastapi.metacpan.org/v1/file/_search -d '{
"query": {
"match_all": {}
},
"size": 1000,
"fields": [ "name", "status", "directory", "path", "distribution" ],
"filter": {
"and": [
{ "term": { "directory": false } }, { "term" : { "path" : "" } }
]
}
}'List releases which have an email address for a bugtracker, but not an url
curl -XPOST https://fastapi.metacpan.org/v1/release/_search -d '{
"query": {
"match_all": {}
},
"size": 10,
"fields": [ "name", "resources.bugtracker.mailto" ],
"filter": {
"and": [
{ "term": {"maturity": "released"} },
{ "term": {"status": "latest"} },
{ "exists" : { "field" : "resources.bugtracker.mailto" } },
{ "missing" : { "field" : "resources.bugtracker.web" } }
]
}
}'List distributions for which we have RT issues
Search the current PDL documentation for the string axisvals
curl -XPOST https://fastapi.metacpan.org/v1/file/_search -d '{
"query" : { "filtered" : {
"query" : {
"query_string" : {
"query" : "axisvals",
"fields" : [ "pod.analyzed", "module.name" ] }
},
"filter" : { "and" : [
{ "term" : { "distribution" : "PDL" } },
{ "term" : { "status" : "latest" } }
]}
}},
"fields" : [ "documentation", "abstract", "module.name" ],
"size" : 20
}'