3270Web: A Web-Based 3270 Terminal Interface Built with Go

Working with 3270 terminals often means juggling:

• Desktop emulators


• VPN access


• Session configuration headaches


• Fragile automation bridges

For modern workflows — especially remote teams, containerised environments, and browser-centric tooling — this quickly becomes friction.

That’s why 3270Web exists.

3270Web is a web-based 3270 terminal interface written in Go, designed to provide interactive sessions and seamlessly bridge into automation via 3270Connect-compatible workflows.

What Problem Does 3270Web Solve?

Traditional 3270 access models assume:

• A locally installed emulator


• Direct network connectivity


• Human-only interaction

But modern environments increasingly require:

✅ Browser-based access


✅ Container-friendly deployment


✅ Session visibility & logging


✅ Automation integration

3270Web provides exactly that.

What 3270Web Is (and Isn’t)

3270Web is:

• A browser-based 3270 terminal UI


• A Go-based backend service


• A session recording & replay tool


• An automation bridge into 3270Connect

It is not:

• A replacement for mainframe logic


• A pixel-based screen scraper


• A generic SSH/RDP gateway

Think of it as a modern access + workflow capture layer for 3270 systems.

Key Features

▸ Web UI for Interactive 3270 Sessions

Run fully interactive 3270 terminal sessions directly in your browser.

Benefits include:

• No desktop emulator required


• Centralised deployment


• Detailed session logging


• Easier remote access scenarios

▸ Virtual Keyboard Support

3270 terminals rely heavily on:

• Function keys


• Special control sequences


• Non-standard key mappings

3270Web includes a virtual keyboard for complete compatibility with real terminal interaction.

▸ Full 3270 Terminal Settings

Mainframe environments vary widely.

3270Web exposes configurable options such as:

• Terminal models


• Screen dimensions


• Encoding options


• Backend connection parameters

Designed to support virtually any TN3270-compatible backend.

▸ Record Sessions to workflow.json

One of the most powerful capabilities:

👉 Record live terminal sessions directly into a workflow.json file

These workflows are:

✅ Compatible with 3270Connect


✅ Reusable for automation


✅ Human-generated but machine-executed

This turns exploratory or manual sessions into repeatable automation assets.

▸ Load & Playback Workflows

Previously recorded workflows can be:

• Loaded back into the UI


• Replayed interactively


• Used for validation/testing


• Passed directly into 3270Connect

Perfect for:

• Regression testing


• Demo environments


• Workflow debugging


• Training scenarios

▸ Docker & GHCR Deployment

3270Web is built with containerised deployment in mind.

Includes:

• Docker image


• GitHub Container Registry (GHCR) workflow


• Simple infrastructure integration

Ideal for:

✅ Dev/test labs


✅ Remote access gateways


✅ Cloud-hosted tooling


✅ Ephemeral environments

Why Pair 3270Web with 3270Connect?

These tools are intentionally complementary:

A typical flow:

1️⃣ Explore workflow interactively in browser


2️⃣ Record session to workflow.json


3️⃣ Execute at scale via 3270Connect

This bridges the gap between:

👤 Human discovery


🤖 Deterministic automation

Real-World Use Cases

3270Web fits naturally into:

• Legacy modernisation projects


• Remote mainframe access scenarios


• Training & sandbox environments


• Automation workflow design


• Debugging 3270Connect scripts


• Containerised lab setups

Why Go?

Using Go provides:

✅ Compiled, predictable binaries


✅ Low runtime overhead


✅ Strong concurrency support


✅ Easy containerisation


✅ Minimal dependency surface

Important for enterprise and regulated environments.

When 3270Web Makes Less Sense

Honest constraints:

• If you already have stable emulator infrastructure


• If browser access is not permitted


• If workflows change constantly with no repeatability


• If human-only usage is required

Final Thoughts

3270 systems are still mission-critical.

But tooling around them doesn’t need to feel stuck in the 1990s.

3270Web provides:

• Modern browser-based access


• Deep session visibility


• Workflow recording


• Seamless automation integration


• Container-friendly deployment

A small, focused tool solving a very real problem space.

Links

• GitHub: https://github.com/3270io/3270Web


• Automation engine: https://github.com/3270io/3270Connect

If you’re working in:

Mainframe #LegacyModernization #Golang #Automation

…this might save you a surprising amount of friction.