diff --git a/api/src/probot.ts b/api/src/probot.ts
index b589d6e1..fd89c55f 100644
--- a/api/src/probot.ts
+++ b/api/src/probot.ts
@@ -30,13 +30,184 @@ type GetFileResponse = {
   };
 };
 
+
+const getPaths = `
+query getPaths($owner: String!, $repo: String!, $number: Int!, cursor: String = "") {
+  repository(name: $repo, owner: $owner) {
+    pullRequest(number: $number) {
+      id
+      files(first: 2, after: $cursor) {
+        edges {
+          node {
+            path
+          }
+          cursor
+        }
+      }
+    }
+  }
+}
+`
+
+function checkPathsResponse(paths: GetPathsResponse) {
+  const edges = paths.repository.pullRequest.files.edges
+  const docsChanged = edges.some(edge => edge.node.path.startsWith('docs/'))
+  const configChanged = edges.some(edge => ["docs.json", "docs.yaml"].includes(edge.node.path))
+  return docsChanged || configChanged;
+}
+
+function getLastFileCursor(getPathsResponse: GetPathsResponse) {
+  const edges = getPathsResponse.repository.pullRequest.files.edges
+  return edges[edges.length - 1].cursor
+}
+
+
+function checkCommentsResponse(comments: GetCommentsResponse) {
+  const edges = comments.repository.pullRequest.comments.edges
+  const hasCommented = edges.some(edge => edge.node.author.login === "docs-page")
+  return hasCommented;
+}
+
+function getLastCommentCursor(getCommentsResponse: GetCommentsResponse) {
+  const edges = getCommentsResponse.repository.pullRequest.comments.edges
+  return edges[edges.length - 1].cursor
+}
+
+type GetPathsResponse = {
+  repository: {
+    pullRequest: {
+      files: {
+        edges: {
+          node: {
+            path: string
+          }
+          cursor: string
+        }[]
+      }
+    }
+  }
+}
+
+const getFirstComments = `
+  query getComments($owner: String!, $repo: String!, $number: Int!) {
+    repository(name: $repo, owner: $owner) {
+      pullRequest(number: $number) {
+        comments(first: 100) {
+          edges {
+            node {
+              author {
+                login
+              }
+            }
+            cursor
+          }
+          totalCount
+        }
+      }
+    }
+  }
+`
+const getComments = `
+  query getComments($owner: String!, $repo: String!, $number: Int!, cursor: String!) {
+    repository(name: $repo, owner: $owner) {
+      pullRequest(number: $number) {
+        comments(first: 100, after: $cursor) {
+          edges {
+            node {
+              author {
+                login
+              }
+            }
+            cursor
+          }
+        }
+      }
+    }
+  }
+`
+
+type GetCommentsResponse = {
+  repository: {
+    pullRequest: {
+      comments: {
+        edges: {
+          node: {
+            author: {
+              login: string
+            }
+          }
+          cursor: string
+        }[],
+        totalCount?: number
+      }
+    }
+  }
+}
+
+
 const app = (app: Probot) => {
-  app.on('pull_request.opened', async context => {
+  app.on(['pull_request.opened', 'pull_request.synchronize'], async context => {
     app.log.info(context);
 
-    const pull_request = context.payload.pull_request;
+    const { repository, pull_request } = context.payload;
+
+    const totalChangedFiles = pull_request.changed_files;
+
+    let totalFilesChecked = 0;
+    let shouldComment = false;
+    let cursor = '';
 
-    const { repository } = context.payload;
+    // check files in batches of 100 until we find a docs file or we've checked all files
+    while (totalFilesChecked < totalChangedFiles && !shouldComment) {
+
+      const getPathsResponse = await context
+        .octokit
+        .graphql<GetPathsResponse>(getPaths, {
+          owner: repository.owner.login,
+          repo: repository.name,
+          number: pull_request.number,
+          cursor
+        });
+
+      shouldComment = checkPathsResponse(getPathsResponse);
+      cursor = getLastFileCursor(getPathsResponse);
+    }
+
+    // check to see if we've commented before
+    
+
+    // for some reason an empty cursor doesn't work for comments, so we have to obtain the first cursor manually.
+    const getFirstCommentsResponse = await context
+    .octokit
+    .graphql<GetCommentsResponse>(getFirstComments, {
+      owner: repository.owner.login,
+      repo: repository.name,
+      number: pull_request.number,
+    });
+    
+    let totalComments = getFirstCommentsResponse.repository.pullRequest.comments.totalCount;
+    let totalCommentsChecked = getFirstCommentsResponse.repository.pullRequest.comments.edges.length;
+    let commentCursor = getLastCommentCursor(getFirstCommentsResponse);
+    let hasCommented = checkCommentsResponse(getFirstCommentsResponse);
+    
+    while (totalCommentsChecked < totalComments! && !hasCommented) {
+      const getCommentsResponse = await context
+        .octokit
+        .graphql<GetCommentsResponse>(getComments, {
+          owner: repository.owner.login,
+          repo: repository.name,
+          number: pull_request.number,
+          cursor: commentCursor
+        });
+        hasCommented = checkCommentsResponse(getCommentsResponse);
+        commentCursor = getLastCommentCursor(getCommentsResponse);
+    }
+
+    shouldComment = shouldComment && !hasCommented;
+
+    if (!shouldComment) {
+      return;
+    }
 
     // e.g. org/repo
     const name = repository.full_name.toLowerCase();