diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..beb679f
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,38 @@
+root = true
+
+[.*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{yml,yaml}]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[Makefile]
+charset = utf-8
+end_of_line = lf
+indent_style = tab
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.sh]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..ca79ca5
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
new file mode 100644
index 0000000..8444a0f
--- /dev/null
+++ b/.github/workflows/test.yaml
@@ -0,0 +1,18 @@
+name: Tests
+
+on:
+  workflow_dispatch: {}
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  tests:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Run tests
+        shell: bash
+        run: make test
diff --git a/.shellcheckrc b/.shellcheckrc
new file mode 100644
index 0000000..8226afb
--- /dev/null
+++ b/.shellcheckrc
@@ -0,0 +1 @@
+external-sources=true
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..6da3c26
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+.PHONY: all test clean
+
+PLATFORM := $(shell docker version --format '{{.Server.Os}}/{{.Server.Arch}}')
+DOCKER := docker run --rm --network none --platform $(PLATFORM)
+
+test: unit-tests lint
+
+unit-tests:
+	@set -e; \
+	for f in tests/test*.sh; do \
+		echo "sh $$f"; \
+		sh "$$f"; \
+	done
+
+lint:
+	$(DOCKER) -v ./Makefile:/work/Makefile:ro backplane/checkmake Makefile
+	$(DOCKER) -v .:/workspace:ro mstruebing/editorconfig-checker ec -exclude '^\.git/'
+	$(DOCKER) -v .:/mnt:ro koalaman/shellcheck -a -s sh --source-path=tests src/** tests/**
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..ee2a6a6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,73 @@
+[![Build and Test](https://github.com/codereaper/create-issue-action/actions/workflows/test.yaml/badge.svg)](https://github.com/codereaper/create-issue-action/actions/workflows/test.yaml)
+
+# Create Issue Action
+
+A simple GitHub Action that **creates, updates, comments on, or closes issues** using the GitHub CLI (`gh`).
+
+Ideal for CI/CD workflows that need to:
+
+- Automatically open or update tracking issues
+- Comment on existing issues from automation
+- Close issues after builds or deployments are complete
+
+## Features
+
+- Create new issues with titles, bodies, templates, labels, and assignees
+- Update existing issues automatically
+- Add comments to existing issues
+- Close issues by title and label search
+- Uses `gh` CLI under the hood (no extra dependencies)
+
+## Inputs
+
+| Name        | Description                                                                       | Default                    | Required |
+| ----------- | --------------------------------------------------------------------------------- | -------------------------- | -------- |
+| `token`     | GitHub token (PAT or `${{ github.token }}`) used for authentication               | `${{ github.token }}`      | Yes      |
+| `mode`      | Operation mode: `create` or `close`                                               | `create`                   | Yes      |
+| `state`     | Issue state filter when searching for existing issues: `open`, `closed`, or `all` | `open`                     | Yes      |
+| `title`     | Title of the issue to create or update                                            | —                          | Yes      |
+| `labels`    | Comma-separated list of labels used for creation and search                       | —                          | No       |
+| `assignees` | Comma-separated list of users to assign the issue to                              | —                          | No       |
+| `body`      | Custom body text for the issue (overrides `template`)                             | —                          | No       |
+| `comment`   | Optional comment text to add to an existing issue                                 | —                          | No       |
+| `repo`      | Repository to operate on (`owner/repo`)                                           | `${{ github.repository }}` | Yes      |
+
+## Example Usage
+
+```yaml
+name: Reporting on failed builds
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build
+        run: make build
+
+  report-failure:
+    runs-on: ubuntu-latest
+    needs: build
+    if: failure()
+    permissions:
+      contents: read
+      issues: write
+    steps:
+      - name: Report build failure
+         uses: CodeReaper/create-issue-action@v1
+        with:
+          title: "{{ github.workflow }} failed to build"
+          labels: automation
+          assignees: "@me"
+          body: See [the action log](https://github.com/{{ github.repository }}/actions/runs/{{ github.run_id }}) for more details.
+```
+
+# License
+
+This project is released under the [MIT License](LICENSE)
diff --git a/action.yaml b/action.yaml
new file mode 100644
index 0000000..e6bae5d
--- /dev/null
+++ b/action.yaml
@@ -0,0 +1,74 @@
+name: Create issue
+description: Creates an issue
+
+branding:
+  icon: git-pull-request
+  color: gray-dark
+
+inputs:
+  token:
+    description: Your Github PAT, defaults to actions token
+    default: ${{ github.token }}
+    required: true
+  repo:
+    description: GitHub repository to create/update/close an issue in
+    default: ${{ github.repository }}
+    required: true
+  mode:
+    description: >
+      Dictates whether to create, update or close an issue.
+      Valid options: create | close
+    default: create
+  state:
+    description: >
+      State of issue to create, update or close.
+      Valid options: open | closed | all
+    default: open
+  title:
+    description: Title of issue to create or update
+    required: true
+  labels:
+    description: Labels (comma-separated) to both create the issue with and to filter the existing issue search with
+    required: false
+  assignees:
+    description: GitHub handle of the user(s) to assign the issue (comma-separated), only used for issue creation
+    required: false
+  body:
+    description: Body text of the issue
+    required: false
+  comment:
+    description: >
+      If set, an existing issue have this comment added to the issue.
+      Note, if the mode is set to create, then any previously added comment is updated instead
+    required: false
+
+outputs:
+  url:
+    description: URL of the issue that was created
+    value: ${{ steps.action.outputs.url }}
+
+runs:
+  using: composite
+  steps:
+    - name: Check dependencies are installed
+      shell: bash
+      run: |
+        if ! command -v gh >/dev/null 2>&1; then
+          echo "Command gh not found. This CLI tool is required."
+          exit 1
+        fi
+
+    - name: Create issue
+      id: action
+      shell: bash
+      env:
+        GH_TOKEN: ${{ inputs.token }}
+        INPUT_REPO: ${{ inputs.repo }}
+        INPUT_MODE: ${{ inputs.mode }}
+        INPUT_STATE: ${{ inputs.state }}
+        INPUT_TITLE: ${{ inputs.title }}
+        INPUT_LABELS: ${{ inputs.labels }}
+        INPUT_ASSIGNEES: ${{ inputs.assignees }}
+        INPUT_BODY: ${{ inputs.body }}
+        INPUT_COMMENT: ${{ inputs.comment }}
+      run: chmod +x "${{ github.action_path }}/scripts/main.sh" && "${{ github.action_path }}/src/main.sh"
diff --git a/src/main.sh b/src/main.sh
new file mode 100644
index 0000000..29a3666
--- /dev/null
+++ b/src/main.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+# cspell:ignore endgroup
+
+set -eu
+
+MODE="${INPUT_MODE:-create}"
+STATE="${INPUT_STATE:-open}"
+TITLE="${INPUT_TITLE}"
+LABELS="${INPUT_LABELS:-}"
+ASSIGNEES="${INPUT_ASSIGNEES:-}"
+BODY="${INPUT_BODY:-}"
+COMMENT="${INPUT_COMMENT:-}"
+REPO="${INPUT_REPO:-}"
+
+BODY_PRESENCE=${BODY:+(set)}
+COMMENT_PRESENCE=${COMMENT:+(set)}
+
+echo "::group::Debug info:"
+echo "  REPO:        ${REPO}"
+echo "  MODE:        ${MODE}"
+echo "  STATE:       ${STATE}"
+echo "  TITLE:       ${TITLE}"
+echo "  LABELS:      ${LABELS}"
+echo "  ASSIGNEES:   ${ASSIGNEES}"
+echo "  BODY:        ${BODY_PRESENCE:-(not set)}"
+echo "  COMMENT:     ${COMMENT_PRESENCE:-(not set)}"
+echo '::endgroup::'
+
+ISSUE_NUMBER=$(gh issue list --repo "${REPO}" --state "${STATE}" --label "${LABELS}" --search "in:title \"${TITLE}\"" --limit 1 --json number --jq '.[].number' || true)
+
+# Perform action based on mode
+case "${MODE}" in
+create)
+  # Determine body args
+  if [ -n "${BODY}" ]; then
+    BODY_ARGS="\"${BODY}\""
+  else
+    BODY_ARGS="\"Auto-generated issue with title: ${TITLE}\""
+  fi
+
+  if [ -n "${ISSUE_NUMBER}" ]; then
+    echo "Issue already exists (#${ISSUE_NUMBER}), updating instead."
+    if [ -n "${COMMENT}" ]; then
+      echo "Adding comment to existing issue..."
+      gh issue comment "${ISSUE_NUMBER}" --repo "${REPO}" --body "${COMMENT}"
+    else
+      echo "Updating issue body..."
+      gh issue edit "${ISSUE_NUMBER}" --repo "${REPO}" --title "${TITLE}" --body "${BODY_ARGS}"
+    fi
+  else
+    echo "Creating new issue..."
+    gh issue create --repo "${REPO}" --title "${TITLE}" --body "${BODY_ARGS}" --label "${LABELS}" --assignee "${ASSIGNEES}"
+  fi
+  ;;
+close)
+  if [ -z "${ISSUE_NUMBER}" ]; then
+    echo "No matching issue found to close."
+    exit 0
+  fi
+  if [ -n "${COMMENT}" ]; then
+    echo "Adding closure comment..."
+    gh issue comment "${ISSUE_NUMBER}" --repo "${REPO}" --body "${COMMENT}"
+  fi
+  echo "Closing issue #${ISSUE_NUMBER}..."
+  gh issue close "${ISSUE_NUMBER}" --repo "${REPO}"
+  ;;
+*)
+  echo "Invalid mode '${MODE}'. Valid options: create | close"
+  exit 1
+  ;;
+esac
+
+echo "Done."
diff --git a/tests/gh.sh b/tests/gh.sh
new file mode 100644
index 0000000..18717c4
--- /dev/null
+++ b/tests/gh.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+set -eu
+
+case "$*" in
+*"issue list"*)
+  # Simulate no issue found unless overridden
+  if [ "${GH_FAKE_MODE:-none}" = "issue-exists" ]; then
+    echo '42'
+  else
+    echo ''
+  fi
+  ;;
+*"issue create"*)
+  echo "FAKE: created issue"
+  ;;
+*"issue edit"*)
+  echo "FAKE: edited issue"
+  ;;
+*"issue comment"*)
+  echo "FAKE: added comment"
+  ;;
+*"issue close"*)
+  echo "FAKE: closed issue"
+  ;;
+*)
+  echo "FAKE: unknown gh command $*" >&2
+  exit 1
+  ;;
+esac
diff --git a/tests/test-add-comment-to-existing-issue.sh b/tests/test-add-comment-to-existing-issue.sh
new file mode 100644
index 0000000..31df624
--- /dev/null
+++ b/tests/test-add-comment-to-existing-issue.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+set -eu
+
+export GH_FAKE_MODE="issue-exists"
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_TITLE="Hello world"
+export INPUT_COMMENT="Hello comment of world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "Adding comment to existing issue..."
+assert_contains "$output" "FAKE: added comment"
+echo "passed"
diff --git a/tests/test-close-existing-issue-with-comment.sh b/tests/test-close-existing-issue-with-comment.sh
new file mode 100644
index 0000000..03f5c65
--- /dev/null
+++ b/tests/test-close-existing-issue-with-comment.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+set -eu
+
+export GH_FAKE_MODE="issue-exists"
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_MODE="close"
+export INPUT_TITLE="Hello world"
+export INPUT_COMMENT="Hello comment of world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "Adding closure comment..."
+assert_contains "$output" "FAKE: added comment"
+assert_contains "$output" "Closing issue #42..."
+assert_contains "$output" "FAKE: closed issue"
+echo "passed"
diff --git a/tests/test-close-existing-issue.sh b/tests/test-close-existing-issue.sh
new file mode 100644
index 0000000..dea8d4c
--- /dev/null
+++ b/tests/test-close-existing-issue.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+set -eu
+
+export GH_FAKE_MODE="issue-exists"
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_MODE="close"
+export INPUT_TITLE="Hello world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "Closing issue #42..."
+assert_contains "$output" "FAKE: closed issue"
+echo "passed"
diff --git a/tests/test-close-with-no-matches.sh b/tests/test-close-with-no-matches.sh
new file mode 100644
index 0000000..f866e61
--- /dev/null
+++ b/tests/test-close-with-no-matches.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+set -eu
+
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_MODE="close"
+export INPUT_TITLE="Hello world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "No matching issue found to close."
+echo "passed"
diff --git a/tests/test-create-new-issue.sh b/tests/test-create-new-issue.sh
new file mode 100644
index 0000000..4b20836
--- /dev/null
+++ b/tests/test-create-new-issue.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+set -eu
+
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_TITLE="Hello world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "Creating new issue..."
+assert_contains "$output" "FAKE: created issue"
+echo "passed"
diff --git a/tests/test-update-existing-issue.sh b/tests/test-update-existing-issue.sh
new file mode 100644
index 0000000..8cb1315
--- /dev/null
+++ b/tests/test-update-existing-issue.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+set -eu
+
+export GH_FAKE_MODE="issue-exists"
+# shellcheck source=utils.sh
+. tests/utils.sh
+
+export INPUT_TITLE="Hello world"
+output=$(bash "${SCRIPT_PATH}" 2>&1)
+assert_contains "$output" "Issue already exists (#42)"
+assert_contains "$output" "FAKE: edited issue"
+echo "passed"
diff --git a/tests/utils.sh b/tests/utils.sh
new file mode 100644
index 0000000..bab041d
--- /dev/null
+++ b/tests/utils.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+set -eu
+
+SCRIPT_PATH=src/main.sh
+TMPDIR=$(mktemp -d)
+FAKE_GH="${TMPDIR}/gh"
+PATH="${TMPDIR}:${PATH}"
+
+# Assert helper
+assert_contains() {
+  haystack="$1"
+  needle="$2"
+
+  # if ! eval printf "%s" "$haystack" | grep -qF "$needle"; then
+  # if ! grep -qF "$needle" <<<"$haystack"; then
+  if ! printf '%s' "$haystack" | grep -qF "$needle"; then
+    echo "Expected output to contain '$needle' but it didn't"
+    echo "-----"
+    echo "$haystack"
+    echo "-----"
+    exit 1
+  fi
+}
+
+trap 'rm -rf $TMPDIR' EXIT
+cp tests/gh.sh "${FAKE_GH}"
+chmod +x "${FAKE_GH}"
+
+export TMPDIR
+export FAKE_GH
+export PATH
+export SCRIPT_PATH