diff --git a/.circleci/config.yml b/.circleci/config.yml
index 2e51ec2e8..fd719d9b0 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,5 +1,13 @@
-version: 2
+version: 2.1
 jobs:
+  check-linear:
+    machine:
+      image: ubuntu-1604:201903-01
+    steps:
+      - checkout
+      - run:
+          name: Check git history of branch is linear
+          command: tools/check-linear.sh
   build:
     machine:
       image: ubuntu-1604:201903-01
@@ -32,3 +40,21 @@ jobs:
       - run:
           name: Launch build with bazel
           command: echo "bazel build //upload --verbose_failures" | HOMEWORLD_CHROOT="$HOME/autobuild-chroot" USER="circleci" ./build-chroot/enter-ci.sh
+workflows:
+  version: 2
+  workflow:
+    jobs:
+      - check-linear:
+          filters:
+            branches:
+              ignore:
+                - staging
+                - trying
+                - master
+      - build:
+          filters:
+            branches:
+              only:
+                - staging
+                - trying
+                - master
diff --git a/bors.toml b/bors.toml
new file mode 100644
index 000000000..adb5c6e78
--- /dev/null
+++ b/bors.toml
@@ -0,0 +1,14 @@
+status = [
+  "ci/circleci: build",
+  "continuous-integration/jenkins/branch",
+]
+pr_status = [
+  "ci/circleci: check-linear",
+]
+required_approvals = 1
+timeout_sec = 10800 # three hour timeout
+cut_body_after = "---"
+
+[committer]
+name = "hyades-bors[bot]"
+email = "sipb-hyades@mit.edu"
diff --git a/docs/bors-ng-setup.txt b/docs/bors-ng-setup.txt
new file mode 100644
index 000000000..b7566b33b
--- /dev/null
+++ b/docs/bors-ng-setup.txt
@@ -0,0 +1,115 @@
+exit  # this isn't quite a script; some parts are interactive.
+
+### Register Github App
+# https://github.com/bors-ng/bors-ng#step-1-register-a-new-github-app
+# Dashboard URL: https://hijinks.mit.edu:4002/
+# Generate and download a private key (.pem file)
+
+
+### Install dependencies
+
+wget -q -O - https://packages.erlang-solutions.com/debian/erlang_solutions.asc | apt-key add -
+echo 'deb https://packages.erlang-solutions.com/debian stretch contrib' >/etc/apt/sources.list.d/erlang-solutions.list
+
+wget -q -O - https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add -
+echo 'deb https://deb.nodesource.com/node_13.x stretch main' >/etc/apt/sources.list.d/nodesource.list
+
+apt-get update
+apt-get install esl-erlang elixir postgresql nodejs
+
+
+# use this command to generate random secrets when called for:
+# </dev/urandom tr -dc 'a-zA-Z0-9' | head -c64
+
+### User
+useradd -m -U borsng
+
+
+### Database
+sudo -u postgres createuser -P borsng  # generate a random db password
+sudo -u postgres createdb -O borsng borsng
+sudo -u postgres psql -d borsng <<<"CREATE EXTENSION IF NOT EXISTS citext;"
+
+
+### Nginx configuration: requires existing nginx+certbot setup from jenkins-setup.txt
+# Add this location block to /etc/nginx/sites-available/hijinks
+cat <<EOF
+server {
+  listen 4002 ssl;
+  server_name hijinks.mit.edu;
+
+  # copied from jenkins' server block:
+  ssl_certificate /etc/letsencrypt/live/hijinks.mit.edu/fullchain.pem;
+  ssl_certificate_key /etc/letsencrypt/live/hijinks.mit.edu/privkey.pem;
+  include /etc/letsencrypt/options-ssl-nginx.conf;
+  ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
+
+  ssl_trusted_certificate /etc/letsencrypt/live/hijinks.mit.edu/chain.pem;
+  ssl_stapling on;
+  ssl_stapling_verify on;
+  add_header Strict-Transport-Security "max-age=31536000" always;
+
+  location / {
+    include /etc/nginx/proxy_params;
+    proxy_pass http://localhost:4001/;
+    proxy_redirect default;
+  }
+}
+EOF
+
+### Systemd configuration
+cat <<EOF >borsng.service
+[Unit]
+Description=Bors-NG
+After=network.target
+
+[Service]
+Type=simple
+User=borsng
+WorkingDirectory=/home/borsng/bors-ng
+EnvironmentFile=/home/borsng/bors-env
+Restart=on-failure
+ExecStart=/home/borsng/bors-ng/_build/prod/rel/bors/bin/bors start
+ExecStop=/home/borsng/bors-ng/_build/prod/rel/bors/bin/bors stop
+
+[Install]
+WantedBy=multi-user.target
+EOF
+ln -s "$(realpath borsng.service)" /etc/systemd/system
+systemctl enable borsng
+
+
+sudo -iu borsng  # run all remaining commands as borsng
+umask go=
+
+git clone https://github.com/bors-ng/bors-ng.git
+
+cd bors-ng
+mix local.hex --force
+mix deps.get --only prod
+mix local.rebar --force
+
+pushd assets
+npm install
+popd
+npm run deploy --prefix ./assets
+MIX_ENV=prod mix phx.digest
+
+MIX_ENV=prod mix compile
+MIX_ENV=prod mix release
+
+
+cat >~/bors-env <<EOF
+PORT=4001
+MIX_ENV=prod
+SECRET_KEY_BASE=???  # generate this randomly
+DATABASE_URL='ecto://borsng:<db password>@localhost/borsng'  # password from earlier
+GITHUB_INTEGRATION_ID=???  # App id in github
+GITHUB_WEBHOOK_SECRET=???  # generate this randomly and input it to github
+GITHUB_CLIENT_ID=???  # from github
+GITHUB_CLIENT_SECRET=???  # from github
+PUBLIC_HOST=localhost
+EOF
+echo "GITHUB_INTEGRATION_PEM='$(base64 -w0 /path/to/file.private-key.pem)'" >>~bors-env  # private key from github
+
+sh -ac '. ~/bors-env && POOL_SIZE=1 mix ecto.migrate'
diff --git a/tools/check-linear.sh b/tools/check-linear.sh
new file mode 100755
index 000000000..2d7f85c60
--- /dev/null
+++ b/tools/check-linear.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+set -euo pipefail
+
+if [ 0 = "$(git rev-list --min-parents=2 --count "$(git merge-base origin/master HEAD)"..HEAD)" ]
+then
+    echo 'git history is linear'
+else
+    echo 'error: nonlinear branch git history'
+    echo 'merge commits:'
+    git rev-list --min-parents=2 "$(git merge-base origin/master HEAD)"..HEAD
+    exit 1
+fi