akihito

Posted on May 12

Lean, Fast, Simple — npm-free GAS Deployment on GitHub Actions with glasp

#automation #cicd #github #go

In the last article, I introduced glasp, a Go-based CLI tool for Google Apps Script (GAS) that operates without a dependency on Node.js.

Previous Article: glasp — A Go-based, zero-dependency CLI for Google Apps Script (clasp Alternative)

GitHub Repository: takihito/glasp

In this post, we will focus on the following:

The benefits of being "npm-independent" in CI/CD environments using GitHub Actions.
A performance comparison between clasp and glasp.

1. "npm-Independence" in GitHub Actions

It is common to see developers using clasp within GitHub Actions to handle deploy or push operations. Typically, the workflow involves these steps:

Setting up the Node.js environment via actions/setup-node.
Installing the tool via npm install -g @google/clasp.

However, this standard approach presents a few challenges.

Reducing Startup Time

npm install can take anywhere from tens of seconds to several minutes, depending on network conditions and cache status.
glasp, on the other hand, is a single binary built with Go. It requires neither the Node.js runtime nor the extraction of a massive node_modules folder. By using the takihito/glasp action for GitHub Actions, you execute the binary directly, significantly reducing environment setup overhead.

Lowering Supply Chain Risk

While the Node.js ecosystem is incredibly powerful, the sheer number of dependency packages increases the risk of vulnerabilities (exposure to supply chain attacks). While multi-functional CLIs like clasp carry many transitive dependencies, glasp is provided as a static binary independent of external runtimes. This keeps your CI environment's stability and security much simpler.

2. Performance Comparison

I conducted a comparison across several metrics.

Lead Time from Setup to Execution

Because glasp eliminates the need to build a Node.js environment, there is a massive difference in the lead time before execution begins.

Metric	glasp	clasp	Speed Ratio (vs clasp)
Setup Time	1,337ms	19,150ms	14.3x
Push Time (Avg)	1,015ms	1,229ms	1.2x
Pull Time (Avg)	359ms	1,270ms	3.5x
Total Time	2,711ms	21,649ms	7.9x

The most significant advantage is the Setup Time. While clasp requires a global installation via npm install -g @google/clasp every time (taking roughly 19 seconds), glasp finishes in about 1.3 seconds just by fetching the pre-compiled single binary. The total cycle of setup → push → pull is 7.9 times faster, a benefit that compounds in pipelines with high deployment frequencies.

Execution Speed (Push/Pull)

glasp optimizes file scanning and upload processes through concurrent processing using Goroutines. While the difference might be subtle in small projects, projects with a large number of files or heavy content benefit greatly from Go’s runtime characteristics and optimized I/O.

Reference: glasp Documentation - GitHub Actions

3. Practical Example: GitHub Actions Configuration

Defining a GitHub Action with glasp is simple. Just remove the setup-node step and call the action directly.

name: Deploy GAS
on:
  push:
    branches: [ main ]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4 # Use the latest stable version

      - uses: takihito/glasp@v0.2.9
        with:
          version: 'v0.2.9'
          auth: ${{ secrets.CLASPRC_JSON }}

Simply register the contents of your local ~/.clasprc.json as a GitHub Secret named CLASPRC_JSON, and you are ready to go.

4. Conclusion

clasp is the official tool and remains a solid choice for Node.js-centric development environments. However, if you have requirements such as:

Reducing CI execution time
Removing dependencies on Node.js (npm-independence)
Building a simple, robust binary-based workflow

Then I encourage you to give glasp a try.

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