diff --git a/services/base-json.js b/services/base-json.js
index 8425a2d192..5584531b50 100644
--- a/services/base-json.js
+++ b/services/base-json.js
@@ -15,7 +15,7 @@ class BaseJsonService extends BaseService {
     })
     if (error) {
       this.logTrace(
-        'error',
+        'validate',
         emojic.womanShrugging,
         'Response did not match schema',
         error.message
diff --git a/services/librariesio/librariesio-base.js b/services/librariesio/librariesio-base.js
new file mode 100644
index 0000000000..bb45901725
--- /dev/null
+++ b/services/librariesio/librariesio-base.js
@@ -0,0 +1,49 @@
+'use strict'
+
+const Joi = require('joi')
+const BaseJsonService = require('../base-json')
+const { InvalidResponse } = require('../errors')
+const { nonNegativeInteger } = require('../validators')
+
+// API doc: https://libraries.io/api#project
+// We distinguishb between packages and repos based on the presence of the
+// `platform` key.
+const packageSchema = Joi.object({
+  platform: Joi.string().required(),
+  dependents_count: nonNegativeInteger,
+  dependent_repos_count: nonNegativeInteger,
+}).required()
+
+const repoSchema = Joi.object({
+  platform: Joi.any().forbidden(),
+}).required()
+
+const packageOrRepoSchema = Joi.alternatives(repoSchema, packageSchema)
+
+class LibrariesIoBase extends BaseJsonService {
+  static buildUrl(base) {
+    return {
+      base,
+      format: '(\\w+)/(.+)',
+      capture: ['platform', 'packageName'],
+    }
+  }
+
+  async fetch({ platform, packageName }, { allowPackages, allowRepos } = {}) {
+    const json = await this._requestJson({
+      schema: packageOrRepoSchema,
+      url: `https://libraries.io/api/${platform}/${packageName}`,
+      notFoundMessage: 'package not found',
+    })
+    const isPackage = Boolean(json.platform)
+    if (isPackage && !allowPackages) {
+      throw new InvalidResponse({ prettyMessage: 'not supported for packages' })
+    }
+    if (!isPackage && !allowRepos) {
+      throw new InvalidResponse({ prettyMessage: 'not supported for repos' })
+    }
+    return json
+  }
+}
+
+module.exports = LibrariesIoBase
diff --git a/services/librariesio/librariesio-dependent-repos.service.js b/services/librariesio/librariesio-dependent-repos.service.js
new file mode 100644
index 0000000000..39f531b8b8
--- /dev/null
+++ b/services/librariesio/librariesio-dependent-repos.service.js
@@ -0,0 +1,50 @@
+'use strict'
+
+const { metric } = require('../../lib/text-formatters')
+const LibrariesIoBase = require('./librariesio-base')
+
+// https://libraries.io/api#project-dependent-repositories
+class LibrariesIoDependentRepos extends LibrariesIoBase {
+  static get category() {
+    return 'other'
+  }
+
+  static get defaultBadgeData() {
+    return {
+      label: 'dependent repos',
+    }
+  }
+
+  static get url() {
+    return this.buildUrl('librariesio/dependent-repos')
+  }
+
+  static get examples() {
+    return [
+      {
+        title: 'Dependent repos (via libraries.io)',
+        previewUrl: 'npm/got',
+      },
+    ]
+  }
+
+  static render({ dependentReposCount }) {
+    return {
+      message: metric(dependentReposCount),
+      color: dependentReposCount === 0 ? 'orange' : 'brightgreen',
+    }
+  }
+
+  async handle({ platform, packageName }) {
+    const { dependent_repos_count: dependentReposCount } = await this.fetch(
+      {
+        platform,
+        packageName,
+      },
+      { allowPackages: true }
+    )
+    return this.constructor.render({ dependentReposCount })
+  }
+}
+
+module.exports = LibrariesIoDependentRepos
diff --git a/services/librariesio/librariesio-dependent-repos.tester.js b/services/librariesio/librariesio-dependent-repos.tester.js
new file mode 100644
index 0000000000..e159090c6a
--- /dev/null
+++ b/services/librariesio/librariesio-dependent-repos.tester.js
@@ -0,0 +1,29 @@
+'use strict'
+
+const Joi = require('joi')
+const ServiceTester = require('../service-tester')
+const { isMetric } = require('../test-validators')
+
+const t = new ServiceTester({
+  id: 'librariesio-dependent-repos',
+  title: 'Libraries.io dependent repos',
+  pathPrefix: '/librariesio/dependent-repos',
+})
+module.exports = t
+
+t.create('dependent repo count')
+  .get('/npm/got.json')
+  .expectJSONTypes(
+    Joi.object().keys({
+      name: 'dependent repos',
+      value: isMetric,
+    })
+  )
+
+t.create('dependent repo count (not a package)')
+  .get('/npm/foobar-is-not-package.json')
+  .timeout(10000)
+  .expectJSON({
+    name: 'dependent repos',
+    value: 'package not found',
+  })
diff --git a/services/librariesio/librariesio-dependents.service.js b/services/librariesio/librariesio-dependents.service.js
new file mode 100644
index 0000000000..7f9e6544fb
--- /dev/null
+++ b/services/librariesio/librariesio-dependents.service.js
@@ -0,0 +1,50 @@
+'use strict'
+
+const { metric } = require('../../lib/text-formatters')
+const LibrariesIoBase = require('./librariesio-base')
+
+// https://libraries.io/api#project-dependents
+class LibrariesIoDependents extends LibrariesIoBase {
+  static get category() {
+    return 'other'
+  }
+
+  static get defaultBadgeData() {
+    return {
+      label: 'dependents',
+    }
+  }
+
+  static get url() {
+    return this.buildUrl('librariesio/dependents')
+  }
+
+  static get examples() {
+    return [
+      {
+        title: 'Dependents (via libraries.io)',
+        previewUrl: 'npm/got',
+      },
+    ]
+  }
+
+  static render({ dependentCount }) {
+    return {
+      message: metric(dependentCount),
+      color: dependentCount === 0 ? 'orange' : 'brightgreen',
+    }
+  }
+
+  async handle({ platform, packageName }) {
+    const { dependents_count: dependentCount } = await this.fetch(
+      {
+        platform,
+        packageName,
+      },
+      { allowPackages: true }
+    )
+    return this.constructor.render({ dependentCount })
+  }
+}
+
+module.exports = LibrariesIoDependents
diff --git a/services/librariesio/librariesio-dependents.tester.js b/services/librariesio/librariesio-dependents.tester.js
new file mode 100644
index 0000000000..8a0bf1dd54
--- /dev/null
+++ b/services/librariesio/librariesio-dependents.tester.js
@@ -0,0 +1,36 @@
+'use strict'
+
+const Joi = require('joi')
+const ServiceTester = require('../service-tester')
+const { isMetric } = require('../test-validators')
+
+const t = new ServiceTester({
+  id: 'librariesio-dependents',
+  title: 'Libraries.io dependents',
+  pathPrefix: '/librariesio/dependents',
+})
+module.exports = t
+
+t.create('dependent count')
+  .get('/npm/got.json')
+  .expectJSONTypes(
+    Joi.object().keys({
+      name: 'dependents',
+      value: isMetric,
+    })
+  )
+
+t.create('dependent count (nonexistent package)')
+  .get('/npm/foobar-is-not-package.json')
+  .timeout(10000)
+  .expectJSON({
+    name: 'dependents',
+    value: 'package not found',
+  })
+
+t.create('dependent count (repo)')
+  .get('/github/sindresorhus/got.json')
+  .expectJSON({
+    name: 'dependents',
+    value: 'not supported for repos',
+  })
diff --git a/services/npm/npm-base.js b/services/npm/npm-base.js
index 692d0e272a..3aa86a7986 100644
--- a/services/npm/npm-base.js
+++ b/services/npm/npm-base.js
@@ -22,7 +22,7 @@ const schema = Joi.object({
 // Abstract class for NPM badges which display data about the latest version
 // of a package.
 module.exports = class NpmBase extends BaseJsonService {
-  static buildUrl(base, { withTag }) {
+  static buildUrl(base, { withTag } = {}) {
     if (withTag) {
       return {
         base,