How to Contribute to denoland/celld: Complete Contribution Guidelines

Contribute to celld by emailing patches to ry@deno.com instead of opening pull requests, which are permanently disabled.

The celld repository is Deno's self-hosted, distributed implementation of Cloudflare Durable Objects. While most open-source projects accept GitHub pull requests, celld follows a unique email-based workflow designed to encourage thoughtful, focused contributions and respect maintainer review time.

Why Celld Uses Patched-Based Contributions

According to the README.md § Contributions, pull requests are explicitly disabled. The maintainer explains: "Thoughtful contributions are welcome; please understand the code, keep the patch focused, and respect the review time you are asking for."

This workflow ensures contributors deeply understand the codebase before submitting changes and prevents drive-by contributions that burden reviewers.

Step-by-Step Contribution Process for Celld

1. Clone and Prepare Your Changes

Start by cloning the repository and creating a focused branch for your change:

# Clone the repo

git clone https://github.com/denoland/celld.git
cd celld

# Create a new branch for your change

git checkout -b my-fix

# Edit files ...

2. Generate a Mail-Friendly Patch

Once your changes are complete and tested, create a patch file using git format-patch:

# Create the patch from your most recent commit

git format-patch -1 HEAD

This generates a file like 0001-feat-cli-add-log-level-flag.patch in your working directory.

3. Verify Your Patch Quality

Before sending, review your .patch file to ensure it meets these criteria:

• Single logical change — one patch per concern
• Clear commit message — explain what changed and why
• Self-contained — no dependencies on other pending patches
• Respects existing conventions — follow Rust formatting, error handling, and async patterns used in the surrounding code

4. Email Your Patch to the Maintainer

Send the patch file as an attachment to ry@deno.com. Include a brief message describing:

• The problem your patch solves
• How you tested it
• Any architectural decisions worth noting

5. CLA and Review Process

By emailing your patch, you automatically grant Deno Land Inc. a Contributor License Agreement (CLA) — no separate signature required. The maintainer will review your patch via email, possibly request revisions, and apply it directly if accepted.

Understanding Celld's Architecture Before Contributing

Familiarize yourself with these core components to make well-targeted contributions:

Component	Purpose	Key Files
Node & Fleet	V8 isolate runtime and Wrangler bundle processing	crates/celld/main.rs
LTX Log Format	Durable replication log for write durability	crates/ltx/src/ltx.rs
Logic Layer	Core Durable Object primitives (KV, HTTP, Cron)	crates/logic/lib.rs
Deployment Protocol	Wrangler bundle parsing and celld deploy behavior	crates/celld/deploy.rs
Documentation	User-facing guides and API reference	docs/README.md

Practical Example: Adding a CLI Flag to Celld

Suppose you want to add a --log-level flag. Here's the complete workflow:

Edit the argument parser in crates/celld/main.rs (around line 350):

// In crates/celld/main.rs
let matches = Command::new("celld")
    .arg(Arg::new("log-level")
        .long("log-level")
        .help("Set logging verbosity")
        .default_value("info"))
    .get_matches();

Update environment handling in crates/logic/lib.rs if the flag affects runtime behavior.

Document the change in docs/README.md under the Command-line interface section.

Commit with a clear message:

git add crates/celld/main.rs docs/README.md
git commit -m "feat(cli): add --log-level flag to control verbosity"

Generate and send the patch:

git format-patch -1 HEAD

# Email 0001-feat-cli-add-log-level-flag.patch to ry@deno.com

Essential Files for Celld Contributors

File	Role	Why It Matters
README.md	Project overview and contribution rules	Read before anything else
Cargo.toml (root)	Workspace and dependency declarations	Understand crate structure
crates/celld/main.rs	Binary entry point and CLI parsing	Modify for server/node changes
crates/logic/lib.rs	Core Durable Object API implementation	Modify for KV, HTTP, Cron logic
docs/README.md	End-user documentation	Always update with user-visible changes
crates/ltx/src/ltx.rs	Replication log format	Modify for durability/replication features

Summary

• No pull requests — celld contributions must be emailed as patches to ry@deno.com
• Use git format-patch to generate mail-friendly patch files
• One change per patch — focused submissions review faster
• CLA is automatic — sending the patch grants license to Deno Land Inc.
• Know the architecture — understand crates/celld/main.rs, crates/logic/lib.rs, and crates/ltx/src/ltx.rs before modifying code

Frequently Asked Questions

Why does celld disable pull requests?

The maintainer disables pull requests to ensure contributors understand the code they change and to keep review cycles respectful of maintainer time. The email workflow encourages more deliberate, higher-quality submissions.

What happens to my patch after I email it?

The maintainer reviews your patch, tests it against the existing codebase and CI, and either applies it directly or responds with feedback via email. There is no GitHub-based review interface.

Do I need to sign a CLA separately?

No. According to the README, emailing your patch automatically satisfies the Contributor License Agreement requirement with Deno Land Inc.

Can I contribute documentation fixes the same way?

Yes. Documentation changes in docs/README.md follow the identical patch workflow. Ensure your commit message clearly indicates it's a docs change, such as docs: fix typo in deployment section.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}