Templates

Dev Herald provides pre-built comment templates for common automated signals in your CI pipeline. Templates handle formatting and structure — you pass in the data.

Use templates with the template and template-data inputs on the dev-herald/comment action. Add a sticky-id to update the comment in place on every push.

Available templates

Deployment Status

Surface deployment information directly in PRs — preview URLs, deployment status, and build artifacts.


- name: Post Deployment Status
  uses: dev-herald/comment@v1
  with:
    api-key: ${{ secrets.DEV_HERALD_API_KEY }}
    pr-number: ${{ github.event.pull_request.number }}
    template: DEPLOYMENT
    sticky-id: deployment-status
    template-data: |
      {
        "projectName": "My App",
        "deploymentStatus": "Ready",
        "previewLink": "https://preview-pr-123.myapp.com",
        "deploymentLink": "https://vercel.com/deployments/abc123",
        "showTimestamp": true
      }

Required fields: projectName, deploymentStatus
Optional fields: projectLink, deploymentLink, previewLink, commentsLink, showTimestamp

See the Vercel Preview Comments guide for a full workflow example.

Migration Progress

Track incremental migrations (e.g., JavaScript → TypeScript, old library → new library) with before/after metrics.


- name: Post Migration Progress
  uses: dev-herald/comment@v1
  with:
    api-key: ${{ secrets.DEV_HERALD_API_KEY }}
    pr-number: ${{ github.event.pull_request.number }}
    template: MIGRATION
    sticky-id: migration-progress
    template-data: |
      {
        "migrations": [
          {
            "from": "JavaScript",
            "to": "TypeScript",
            "summary": "✅ This PR converted 5 more files to TypeScript",
            "whyItMatters": "Improves type safety and developer experience",
            "metric": {
              "unit": "files",
              "before": 120,
              "after": 115,
              "delta": -5
            }
          }
        ],
        "showTimestamp": true
      }

Required fields: migrations (array with from, to, summary, and metric)
Optional fields: whyItMatters, showTimestamp

Custom Table

Create structured tables for any data — bundle sizes, coverage reports, performance metrics, and more. Each cell is markdown (GitHub-Flavored Markdown: links, bold, `code`, and more). Literal pipe characters in your markdown are automatically escaped so the table layout stays valid.


- name: Post Bundle Size Analysis
  uses: dev-herald/comment@v1
  with:
    api-key: ${{ secrets.DEV_HERALD_API_KEY }}
    pr-number: ${{ github.event.pull_request.number }}
    template: CUSTOM_TABLE
    sticky-id: bundle-analysis
    template-data: |
      {
        "title": "Bundle Size Analysis",
        "headers": ["Package", "Size", "Change", "Status"],
        "rows": [
          {
            "cells": [
              { "markdown": "[main.js](https://example.com/chunk-main)" },
              { "markdown": "245 KB" },
              { "markdown": "-12 KB ⬇️" },
              { "markdown": "✅ **Improved**" }
            ]
          },
          {
            "cells": [
              { "markdown": "vendor.js" },
              { "markdown": "890 KB" },
              { "markdown": "+5 KB ⬆️" },
              { "markdown": "⚠️ Watch" }
            ]
          }
        ],
        "showTimestamp": true
      }

Required fields: headers, rows (at least one row with cells; each cell has markdown)
Optional fields: title, showTimestamp

See Bundle Change Comments for a workflow that computes and posts bundle diffs.

Template data validation

All templates use Zod schemas for validation. If you provide invalid data, Dev Herald returns a detailed error message explaining what’s wrong.

Next steps

Learn about Sticky Comments to update comments in place
Browse use cases for end-to-end workflow examples