diff --git a/lib/index.js b/lib/index.js
index 7799ceb..56d75a6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -211,6 +211,7 @@ class Client {
 
   /**
    * Incomplete builds
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/builds/builds.go
    */
   incompleteBuilds () {
     return this._axios.get(
@@ -244,6 +245,7 @@ class Client {
    * @param {string} owner Owner of the repo
    * @param {string} repo Name of the repo
    * @param {integer} before Purge before build
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/repos/builds/purge.go
    */
   purgeBuilds (owner, repo, before) {
     Joi.assert(owner, Joi.string().required(), 'Must specify owner')
@@ -280,6 +282,7 @@ class Client {
    * @param {string} owner Owner of the repo
    * @param {string} repo Name of the repo
    * @param {integer} number Number of the build
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/repos/builds/find.go
    */
   getBuild (owner, repo, number) {
     Joi.assert(owner, Joi.string().required(), 'Must specify owner')
@@ -297,6 +300,7 @@ class Client {
    * @param {string} repo Name of the repo
    * @param {integer} number Number of the build
    * @param {RetryBuild} params Build parameters
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/repos/builds/retry.go
    */
   retryBuild (owner, repo, number, params) {
     Joi.assert(owner, Joi.string().required(), 'Must specify owner')
@@ -315,6 +319,7 @@ class Client {
    * @param {string} owner Owner of the repo
    * @param {string} repo Name of the repo
    * @param {integer} number Number of the build
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/repos/builds/cancel.go
    */
   cancelBuild (owner, repo, number) {
     Joi.assert(owner, Joi.string().required(), 'Must specify owner')
@@ -333,6 +338,7 @@ class Client {
    * @param {integer} number Number of the build
    * @param {string} target Promote target
    * @param {object} params Build parameters
+   * Ref: https://github.com/harness/drone/blob/v2.11.1/handler/api/repos/builds/promote.go
    */
   promoteBuild (owner, repo, number, target, params) {
     Joi.assert(owner, Joi.string().required(), 'Must specify owner')
@@ -343,12 +349,12 @@ class Client {
 
     return this._axios.post(
             `/api/repos/${owner}/${repo}/builds/${number}/promote`,
-            Querystring.stringify(
+            new URLSearchParams(
               Object.assign(
                 { target: target },
                 params
               )
-            )
+            ).toString()
     )
   }
 
diff --git a/test/client.js b/test/client.js
index 529ec70..12b50df 100644
--- a/test/client.js
+++ b/test/client.js
@@ -57,25 +57,6 @@ experiment('getRepos', () => {
   })
 })
 
-experiment('getBuilds', () => {
-  beforeEach(() => {
-    sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
-  })
-
-  itValidatesRepoIdentification('getBuilds')
-
-  it('sends proper params to server', () => {
-    client.getBuilds('drone', 'drone-node', 2, 42)
-
-    expect(
-      client._axios.get.lastCall.args
-    ).to.equal([
-      '/api/repos/drone/drone-node/builds',
-      { params: { page: 2, per_page: 42 } }
-    ])
-  })
-})
-
 experiment('selfRepos', () => {
   beforeEach(() => {
     sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
@@ -240,3 +221,150 @@ experiment('updateRepo', () => {
     ])
   })
 })
+
+experiment('incompleteBuilds', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
+  })
+
+  it('sends proper params to server', () => {
+    client.incompleteBuilds()
+
+    expect(
+      client._axios.get.lastCall.args
+    ).to.equal([
+      '/api/builds/incomplete'
+    ])
+  })
+})
+
+experiment('getBuilds', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('getBuilds')
+
+  it('sends proper params to server', () => {
+    client.getBuilds('drone', 'drone-node', 2, 42)
+
+    expect(
+      client._axios.get.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds',
+      { params: { page: 2, per_page: 42 } }
+    ])
+  })
+})
+
+experiment('purgeBuilds', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'delete', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('purgeBuilds')
+
+  it('sends proper params to server', () => {
+    client.purgeBuilds('drone', 'drone-node', 42)
+
+    expect(
+      client._axios.delete.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds',
+      { params: { before: 42 } }
+    ])
+  })
+})
+
+experiment('latestBuild', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('latestBuild')
+
+  it('sends proper params to server', () => {
+    client.latestBuild('drone', 'drone-node', { ref: 'abc123', branch: 'feature-branch' })
+
+    expect(
+      client._axios.get.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds/latest',
+      { params: { ref: 'abc123', branch: 'feature-branch' } }
+    ])
+  })
+})
+
+experiment('getBuild', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'get', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('getBuild')
+
+  it('sends proper params to server', () => {
+    client.getBuild('drone', 'drone-node', 42)
+
+    expect(
+      client._axios.get.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds/42'
+    ])
+  })
+})
+
+experiment('retryBuild', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'post', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('retryBuild')
+
+  it('sends proper params to server', () => {
+    client.retryBuild('drone', 'drone-node', 42, { thing: 'mybuild' })
+
+    expect(
+      client._axios.post.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds/42',
+      'thing=mybuild'
+    ])
+  })
+})
+
+experiment('cancelBuild', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'delete', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('cancelBuild')
+
+  it('sends proper params to server', () => {
+    client.cancelBuild('drone', 'drone-node', 42)
+
+    expect(
+      client._axios.delete.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds/42'
+    ])
+  })
+})
+
+experiment('promoteBuild', () => {
+  beforeEach(() => {
+    sinon.replace(client._axios, 'post', sinon.fake.returns('fake'))
+  })
+
+  itValidatesRepoIdentification('promoteBuild')
+
+  it('sends proper params to server', () => {
+    client.promoteBuild('drone', 'drone-node', 42, 'production', { owner: 'octocat' })
+
+    expect(
+      client._axios.post.lastCall.args
+    ).to.equal([
+      '/api/repos/drone/drone-node/builds/42/promote',
+      'target=production&owner=octocat'
+    ])
+  })
+})