diff --git a/.github/workflows/ralph.yml b/.github/workflows/ralph.yml
new file mode 100644
index 0000000..00a29ae
--- /dev/null
+++ b/.github/workflows/ralph.yml
@@ -0,0 +1,63 @@
+name: Ralph Loop
+
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - "AGENTS.md"
+      - "scripts/ralph/**"
+
+permissions:
+  contents: write
+
+jobs:
+  ralph:
+    # 198982749 is the Copilot app actor id fallback when RALPH_BOT_ID is unset.
+    if: ${{ github.event_name == 'workflow_dispatch' || format('{0}', github.actor_id) == vars.RALPH_BOT_ID || github.actor_id == 198982749 }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.RALPH_PAT }}
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install jq
+        run: sudo apt-get update && sudo apt-get install -y jq
+
+      - name: Install OpenCode
+        run: npm install -g @github/opencode
+
+      - name: Validate state files
+        run: |
+          jq empty scripts/ralph/prd.json
+          jq empty scripts/ralph/constraints.json
+          jq empty scripts/ralph/failure.json
+
+      - name: Ensure guard is executable
+        run: chmod +x scripts/ralph/guard.sh
+
+      - name: Run OpenCode iteration
+        run: opencode run --config .opencode/opencode.json
+
+      - name: Run guard
+        run: bash scripts/ralph/guard.sh scripts/ralph/constraints.json
+
+      - name: Commit and push changes
+        env:
+          GIT_AUTHOR_NAME: ralph-bot
+          GIT_AUTHOR_EMAIL: ralph@example.com
+          GIT_COMMITTER_NAME: ralph-bot
+          GIT_COMMITTER_EMAIL: ralph@example.com
+        run: |
+          if [[ -z "$(git status --porcelain)" ]]; then
+            echo "No changes to commit."
+            exit 0
+          fi
+          git add .
+          git commit -m "chore: ralph iteration"
+          git push
diff --git a/.opencode/opencode.json b/.opencode/opencode.json
new file mode 100644
index 0000000..c51b4d2
--- /dev/null
+++ b/.opencode/opencode.json
@@ -0,0 +1,16 @@
+{
+  "workdir": ".",
+  "agents": [
+    {
+      "id": "ralph",
+      "agentFile": "AGENTS.md",
+      "state": {
+        "prd": "scripts/ralph/prd.json",
+        "progress": "scripts/ralph/progress.txt",
+        "constraints": "scripts/ralph/constraints.json",
+        "failure": "scripts/ralph/failure.json"
+      },
+      "maxIterations": 1
+    }
+  ]
+}
diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..fc8ffa1
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,25 @@
+# Ralph Agents
+
+- PAUSED: false
+- MAX_FAILURE_RETRIES: 3
+- COMMIT_AUTHOR: ralph-bot <ralph@example.com>
+
+## Loop checklist
+1) Load AGENTS.md and scripts/ralph state files.
+2) If paused, exit immediately.
+3) Pick the first `"status": "todo"` story in prd.json and mark it doing before work.
+4) Keep one story per run and make the smallest possible diff.
+5) Run scripts/ralph/guard.sh before committing; never bypass it.
+6) Update progress.txt with a short learning when a story is marked done.
+7) If failures exceed MAX_FAILURE_RETRIES, set PAUSED: true and push state.
+
+## Working files
+- scripts/ralph/prd.json - story queue (todo/doing/done)
+- scripts/ralph/progress.txt - chronological learnings
+- scripts/ralph/constraints.json - guard limits
+- scripts/ralph/failure.json - consecutive failure bookkeeping
+
+## Footguns
+- Do not touch build artifacts (dist, node_modules, .svelte-kit, build).
+- Avoid changing more than 25 files or 400 total lines per iteration.
+- Guard must pass before any commit or push.
diff --git a/README.md b/README.md
index 29e1293..55a472e 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,16 @@ npx create-remote-app my-app
 
 Then follow the setup guide in your new project's README.
 
+## Ralph Loop Automation
+
+This repo includes a minimal Ralph loop to run one story at a time.
+
+1. Add a repo-scoped PAT secret named `RALPH_PAT` (contents + workflow).
+2. Trigger the **Ralph Loop** workflow manually, or push changes to `AGENTS.md` or `scripts/ralph/**` (only bot pushes auto-run).
+3. The loop reads `AGENTS.md` plus `scripts/ralph/{prd.json,progress.txt,constraints.json,failure.json}`, runs `scripts/ralph/guard.sh`, and commits if the guard passes.
+
+State files live under `scripts/ralph/` and `.opencode/opencode.json` wires them into OpenCode.
+
 ## What This Repo Shows
 
 This project demonstrates:
@@ -213,4 +223,4 @@ This is a pragmatic starting point for projects needing authenticated persistent
 ## Requirements
 
 - Node.js + Bun
-- Cloudflare account (for deployment)
\ No newline at end of file
+- Cloudflare account (for deployment)
diff --git a/scripts/ralph/constraints.json b/scripts/ralph/constraints.json
new file mode 100644
index 0000000..9a1dfcd
--- /dev/null
+++ b/scripts/ralph/constraints.json
@@ -0,0 +1,7 @@
+{
+  "maxFilesChanged": 25,
+  "maxLinesChanged": 400,
+  "forbiddenPaths": ["node_modules", "dist", "build", ".svelte-kit", ".next"],
+  "requireProgressUpdate": true,
+  "maxFailureRetries": 3
+}
diff --git a/scripts/ralph/failure.json b/scripts/ralph/failure.json
new file mode 100644
index 0000000..c5a87e9
--- /dev/null
+++ b/scripts/ralph/failure.json
@@ -0,0 +1,6 @@
+{
+  "consecutiveFailures": 0,
+  "lastRunUrl": "",
+  "lastError": "",
+  "lastTimestamp": ""
+}
diff --git a/scripts/ralph/guard.sh b/scripts/ralph/guard.sh
new file mode 100755
index 0000000..24d407f
--- /dev/null
+++ b/scripts/ralph/guard.sh
@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+constraints_file="${1:-}"
+
+if [[ -z "${constraints_file}" ]]; then
+  echo "Usage: $0 <constraints.json>" >&2
+  exit 1
+fi
+
+if ! command -v jq >/dev/null 2>&1; then
+  echo "jq is required for guard checks" >&2
+  exit 1
+fi
+
+if [[ ! -f "${constraints_file}" ]]; then
+  echo "Constraints file not found: ${constraints_file}" >&2
+  exit 1
+fi
+
+if grep -Eq "^[[:space:]]*-[[:space:]]*PAUSED:[[:space:]]*true" AGENTS.md; then
+  echo "Guard blocked: AGENTS.md is paused" >&2
+  exit 1
+fi
+
+max_files=$(jq -r '.maxFilesChanged // 0' "${constraints_file}")
+max_lines=$(jq -r '.maxLinesChanged // 0' "${constraints_file}")
+require_progress=$(jq -r '.requireProgressUpdate // false' "${constraints_file}")
+readarray -t forbidden_paths < <(jq -r '.forbiddenPaths[]?' "${constraints_file}")
+readarray -t changed_list < <(git diff HEAD --name-only)
+
+if [[ ${#changed_list[@]} -eq 0 ]]; then
+  echo "Guard note: no changes detected; nothing to validate."
+  exit 0
+fi
+
+file_count=${#changed_list[@]}
+if [[ "${max_files}" -gt 0 && "${file_count}" -gt "${max_files}" ]]; then
+  echo "Guard failed: ${file_count} files changed (max ${max_files})." >&2
+  exit 1
+fi
+
+line_total=$(git diff HEAD --numstat | awk '{add+=$1; del+=$2} END {total=add+del; if (NR==0) print 0; else print total}')
+if [[ "${max_lines}" -gt 0 && "${line_total}" -gt "${max_lines}" ]]; then
+  echo "Guard failed: ${line_total} total line changes (max ${max_lines})." >&2
+  exit 1
+fi
+
+if [[ ${#forbidden_paths[@]} -gt 0 ]]; then
+  for file in "${changed_list[@]}"; do
+    for path in "${forbidden_paths[@]}"; do
+      [[ -z "${path}" ]] && continue
+      case "${file}" in
+        "${path}"|"${path}"/*)
+          echo "Guard failed: forbidden path touched (${path})." >&2
+          exit 1
+          ;;
+      esac
+    done
+  done
+fi
+
+if [[ "${require_progress}" == "true" ]]; then
+  prd_changed=0
+  progress_changed=0
+  for file in "${changed_list[@]}"; do
+    [[ "${file}" == "scripts/ralph/prd.json" ]] && prd_changed=$((prd_changed+1))
+    [[ "${file}" == "scripts/ralph/progress.txt" ]] && progress_changed=$((progress_changed+1))
+  done
+  if [[ "${prd_changed}" -gt 0 && "${progress_changed}" -eq 0 ]]; then
+    echo "Guard failed: prd.json changed without updating progress.txt." >&2
+    exit 1
+  fi
+fi
+
+echo "Guard passed: constraints satisfied."
diff --git a/scripts/ralph/prd.json b/scripts/ralph/prd.json
new file mode 100644
index 0000000..ab9ad49
--- /dev/null
+++ b/scripts/ralph/prd.json
@@ -0,0 +1,32 @@
+[
+  {
+    "id": "S1",
+    "title": "Boot Ralph automation scaffold",
+    "status": "todo",
+    "acceptanceCriteria": [
+      "Required Ralph state files and OpenCode config exist in the repo",
+      "Guard script is available for later iterations"
+    ],
+    "notes": ""
+  },
+  {
+    "id": "S2",
+    "title": "Add/verify diff guard in CI",
+    "status": "todo",
+    "acceptanceCriteria": [
+      "Guard runs in the Ralph workflow",
+      "Guard fails on forbidden paths or oversized diffs"
+    ],
+    "notes": ""
+  },
+  {
+    "id": "S3",
+    "title": "Update README with usage instructions",
+    "status": "todo",
+    "acceptanceCriteria": [
+      "README documents the Ralph loop triggers",
+      "README lists required secrets and state files"
+    ],
+    "notes": ""
+  }
+]
diff --git a/scripts/ralph/progress.txt b/scripts/ralph/progress.txt
new file mode 100644
index 0000000..7a6a0d2
--- /dev/null
+++ b/scripts/ralph/progress.txt
@@ -0,0 +1,3 @@
+# Ralph Progress
+- Initialized scaffold and baseline state.
+- Clarified story naming and guard behavior.