diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..01081ab
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,26 @@
+# Git and tooling
+.git
+.github
+.justscripts
+.vscode
+
+# Local environment and secrets
+.venv
+.env
+.env.*
+
+# Python caches and output
+**/__pycache__
+**/*.py[cod]
+.pytest_cache
+.ruff_cache
+*.egg-info
+build
+dist
+.coverage
+coverage.xml
+
+# Not used by this image
+docs
+prototype
+packages/cli
diff --git a/.github/scripts/security-summary.js b/.github/scripts/security-summary.js
new file mode 100644
index 0000000..fe5b14d
--- /dev/null
+++ b/.github/scripts/security-summary.js
@@ -0,0 +1,220 @@
+const fs = require("fs");
+
+/**
+ * Parse Trivy scan results and count vulnerabilities
+ */
+function parseScanResults(images) {
+  let totalCritical = 0;
+  let totalHigh = 0;
+  let totalMedium = 0;
+  let totalLow = 0;
+  const imageResults = [];
+
+  for (const image of images) {
+    try {
+      const results = JSON.parse(
+        fs.readFileSync(`trivy-${image}-results.json`, "utf8"),
+      );
+
+      let imageCritical = 0,
+        imageHigh = 0,
+        imageMedium = 0,
+        imageLow = 0;
+
+      if (results.Results) {
+        for (const result of results.Results) {
+          if (result.Vulnerabilities) {
+            for (const vuln of result.Vulnerabilities) {
+              switch (vuln.Severity) {
+                case "CRITICAL":
+                  imageCritical++;
+                  break;
+                case "HIGH":
+                  imageHigh++;
+                  break;
+                case "MEDIUM":
+                  imageMedium++;
+                  break;
+                case "LOW":
+                  imageLow++;
+                  break;
+              }
+            }
+          }
+        }
+      }
+
+      totalCritical += imageCritical;
+      totalHigh += imageHigh;
+      totalMedium += imageMedium;
+      totalLow += imageLow;
+
+      imageResults.push({
+        name: image,
+        critical: imageCritical,
+        high: imageHigh,
+        medium: imageMedium,
+        low: imageLow,
+        total: imageCritical + imageHigh + imageMedium + imageLow,
+        vulnerabilities:
+          results.Results?.flatMap((r) => r.Vulnerabilities ?? []) ?? [],
+      });
+    } catch (error) {
+      console.error(`Error parsing ${image}:`, error);
+      imageResults.push({
+        name: image,
+        error: true,
+        errorMessage: error.message,
+      });
+    }
+  }
+
+  return {
+    totalCritical,
+    totalHigh,
+    totalMedium,
+    totalLow,
+    totalVulns: totalCritical + totalHigh + totalMedium + totalLow,
+    imageResults,
+  };
+}
+
+/**
+ * Format results as GitHub markdown comment
+ */
+function formatGitHubComment(scanResults, repoOwner, repoName) {
+  const {
+    totalCritical,
+    totalHigh,
+    totalMedium,
+    totalLow,
+    totalVulns,
+    imageResults,
+  } = scanResults;
+
+  let message = `## 🔒 Security Scan Results\n\n`;
+  const errors = imageResults.filter((result) => result.error);
+
+  if (errors.length) {
+    message += `### ⚠ Scan incomplete: failed to parse ${errors.length} Trivy result(s).\n\n`
+  }
+
+  // Summary at the top
+  if (totalVulns > 0) {
+    message += `### ⚠️ Found ${totalVulns} vulnerabilities\n\n`;
+    message += `| Severity | Total |\n|----------|-------|\n`;
+    if (totalCritical > 0) message += `| 🔴 Critical | ${totalCritical} |\n`;
+    if (totalHigh > 0) message += `| 🟠 High | ${totalHigh} |\n`;
+    if (totalMedium > 0) message += `| 🟡 Medium | ${totalMedium} |\n`;
+    if (totalLow > 0) message += `| ⚪ Low | ${totalLow} |\n`;
+    message += `\n`;
+  } else if (!errors.length) {
+    message += `### ✅ No vulnerabilities found!\n\n`;
+  }
+
+  // Per-image breakdown
+  for (const result of imageResults) {
+    message += `### 📦 ${result.name}\n\n`;
+
+    if (result.error) {
+      message += `⚠️ Could not parse results for ${result.name}\n\n`;
+    } else if (result.total === 0) {
+      message += `✅ **No vulnerabilities found**\n\n`;
+    } else {
+      message += `| Severity | Count |\n|----------|-------|\n`;
+      if (result.critical > 0)
+        message += `| 🔴 Critical | ${result.critical} |\n`;
+      if (result.high > 0) message += `| 🟠 High | ${result.high} |\n`;
+      if (result.medium > 0) message += `| 🟡 Medium | ${result.medium} |\n`;
+      if (result.low > 0) message += `| ⚪ Low | ${result.low} |\n`;
+      message += `\n`;
+    }
+  }
+
+  message += `\n---\n`;
+  message += `**View detailed results**: [Security tab](https://github.com/${repoOwner}/${repoName}/security/code-scanning)\n`;
+  message += `*Last updated: ${new Date()
+    .toISOString()
+    .replace("T", " ")
+    .replace(/\.\d{3}Z$/, " UTC")}*`;
+
+  return message;
+}
+
+/**
+ * Post or update PR comment
+ */
+async function postGitHubComment(github, context, message) {
+  const prNumber = context.payload.pull_request?.number;
+
+  if (!prNumber) {
+    console.log("Not a PR, skipping GitHub comment");
+    return;
+  }
+
+  const comments = await github.rest.issues.listComments({
+    issue_number: prNumber,
+    owner: context.repo.owner,
+    repo: context.repo.repo,
+  });
+
+  const botComment = comments.data.find(
+    (comment) =>
+      comment.user.login === "github-actions[bot]" &&
+      comment.body.includes("Security Scan Results"),
+  );
+
+  if (botComment) {
+    await github.rest.issues.updateComment({
+      comment_id: botComment.id,
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      body: message,
+    });
+    console.log("Updated existing security scan comment");
+  } else {
+    await github.rest.issues.createComment({
+      issue_number: prNumber,
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      body: message,
+    });
+    console.log("Created new security scan comment");
+  }
+}
+
+/**
+ * For PR scans - posts comment to PR
+ */
+async function generatePRSummary(github, context, core, images = [], isLocalActRun = false) {
+  if (!images.length) return; // no images to generate results for
+
+  // Parse all scan results
+  const scanResults = parseScanResults(images);
+
+  const message = formatGitHubComment(
+    scanResults,
+    context.repo.owner,
+    context.repo.repo,
+  );
+
+  if (isLocalActRun) {
+    // log the message
+    core.info(message);
+    return;
+  }
+
+  // Warn if critical or high vulnerabilities found
+  if (scanResults.totalCritical > 0 || scanResults.totalHigh > 0) {
+    core.warning(
+      `Found ${scanResults.totalCritical} critical and ${scanResults.totalHigh} high severity vulnerabilities`,
+    );
+  }
+
+  // Post GitHub comment
+  await postGitHubComment(github, context, message);
+}
+
+module.exports = {
+  generatePRSummary
+};
diff --git a/.github/workflows/pr-security-scan.yml b/.github/workflows/pr-security-scan.yml
new file mode 100644
index 0000000..ed24b4a
--- /dev/null
+++ b/.github/workflows/pr-security-scan.yml
@@ -0,0 +1,146 @@
+name: PR Security Scan
+
+on:
+  workflow_dispatch:
+  # TODO: uncomment this trigger block when we want this workflow to run on PRs
+  # pull_request:
+  #   branches:
+  #     - "**"
+  # merge_group:
+  #   types:
+  #     - checks_requested
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  TRIVY_SEVERITY: "CRITICAL,HIGH,MEDIUM,LOW"
+
+jobs:
+  build-and-scan:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      security-events: write
+
+    strategy:
+      matrix:
+        image:
+          - name: "did-lambda"
+            dockerfile: "docker/lambda.Dockerfile"
+      fail-fast: false
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@bb05f3f5519dd87d3ba754cc423b652a5edd6d2c # v4.2.0
+
+      - name: Build image locally (no push)
+        uses: docker/build-push-action@53b7df96c91f9c12dcc8a07bcb9ccacbed38856a # v7.3.0
+        env:
+          DOCKER_BUILD_RECORD_UPLOAD: ${{ !env.ACT }}
+        with:
+          context: .
+          file: ${{ matrix.image.dockerfile }}
+          load: true # Load locally for scanning only
+          tags: local-scan/${{ matrix.image.name }}:${{ github.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Run Trivy vulnerability scanner (SARIF)
+        uses: aquasecurity/trivy-action@57a97c7e7821a5776cebc9bb87c984fa69cba8f1 # v0.35.0
+        with:
+          image-ref: local-scan/${{ matrix.image.name }}:${{ github.sha }}
+          format: "sarif"
+          output: "trivy-${{ matrix.image.name }}-results.sarif"
+          severity: ${{ env.TRIVY_SEVERITY }}
+          ignore-unfixed: false
+          timeout: "10m"
+
+      - name: Run Trivy vulnerability scanner (JSON for PR comment)
+        uses: aquasecurity/trivy-action@57a97c7e7821a5776cebc9bb87c984fa69cba8f1 # v0.35.0
+        with:
+          image-ref: local-scan/${{ matrix.image.name }}:${{ github.sha }}
+          format: "json"
+          output: "trivy-${{ matrix.image.name }}-results.json"
+          severity: ${{ env.TRIVY_SEVERITY }}
+          ignore-unfixed: false
+          timeout: "10m"
+
+      - name: Display Trivy results as table
+        uses: aquasecurity/trivy-action@57a97c7e7821a5776cebc9bb87c984fa69cba8f1 # v0.35.0
+        with:
+          image-ref: local-scan/${{ matrix.image.name }}:${{ github.sha }}
+          format: "table"
+
+      - name: Upload Trivy scan results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
+        if: ${{ always() && !env.ACT }}
+        with:
+          sarif_file: "trivy-${{ matrix.image.name }}-results.sarif"
+          category: "pr-scan-${{ matrix.image.name }}"
+
+      - name: Upload JSON results as artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        if: ${{ always() && !env.ACT }}
+        with:
+          name: trivy-results-${{ matrix.image.name }}
+          path: trivy-${{ matrix.image.name }}-results.json
+          retention-days: 5
+
+      - name: Generate scan summary
+        if: always()
+        run: |
+          echo "## Security Scan Results for ${{ matrix.image.name }}" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          if [ -f "trivy-${{ matrix.image.name }}-results.sarif" ]; then
+            echo "Vulnerability scan completed successfully" >> $GITHUB_STEP_SUMMARY
+            echo "Results uploaded to Security tab" >> $GITHUB_STEP_SUMMARY
+            echo "Category: pr-scan-${{ matrix.image.name }}" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "Scan failed or no results generated" >> $GITHUB_STEP_SUMMARY
+          fi
+
+  scan-summary:
+    runs-on: ubuntu-latest
+    needs: build-and-scan
+    if: ${{ always() && github.event_name == 'pull_request' }}
+
+    env:
+      SCAN_IMAGES_CSV: "did-lambda"
+
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Download scan results
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          pattern: trivy-results-*
+          merge-multiple: true
+
+      - name: PR Security Summary with Details
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          script: |
+            const script = require('./.github/scripts/security-summary.js');
+
+            // parse `SCAN_IMAGES_CSV` to array
+            // ex: 'did-lambda,did-api' -> ['did-lambda', 'did-api']
+            const images = (process.env.SCAN_IMAGES_CSV ?? '')
+              .split(',')
+              .map((x) => x.trim())
+              .filter(Boolean);
+
+            const isLocalActRun = process.env.ACT === "true";
+
+            // generate PR summary and add PR comment
+            await script.generatePRSummary(github, context, core, images, isLocalActRun);