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isomorphic-git

Use isomorphic-git in a Cloudflare Worker when you need Git operations without a Git binary.

This works with Artifacts because Artifacts exposes standard Git smart HTTP remotes. In Workers, pair isomorphic-git/http/web with a small in-memory filesystem because the runtime does not expose a local disk.

Install the dependency

Install isomorphic-git in your Worker project:

npm i isomorphic-git

Example

This demo creates a new repo on each request, writes two files, commits them, and pushes main to the new remote.

Use this as a reference for the end-to-end flow. In a production Worker, look up or reuse an existing repo instead of creating a new one for every request.

src/index.js
import git from "isomorphic-git";
import http from "isomorphic-git/http/web";
import { MemoryFS } from "./memory-fs";
export default {
async fetch(_request, env) {
const repoName = `worker-demo-${crypto.randomUUID().slice(0, 8)}`;
const created = await env.ARTIFACTS.create(repoName);
// Artifacts returns art_v1_<secret>?expires=<unix_seconds>.
// For Git Basic auth, pass only the secret as the password.
const tokenSecret = created.token.split("?expires=")[0];
const dir = "/workspace";
const fs = new MemoryFS();
await git.init({ fs, dir, defaultBranch: "main" });
await fs.promises.writeFile(
`${dir}/README.md`,
"# Artifacts repo created from a Worker\n",
);
await fs.promises.writeFile(
`${dir}/src/index.ts`,
'export const message = "hello from Artifacts";\n',
);
await git.add({ fs, dir, filepath: "README.md" });
await git.add({ fs, dir, filepath: "src/index.ts" });
const commit = await git.commit({
fs,
dir,
message: "Create starter files",
author: {
name: "Artifacts example",
email: "artifacts@example.com",
},
});
const push = await git.push({
fs,
http,
dir,
url: created.remote,
ref: "main",
onAuth: () => ({
username: "x",
password: tokenSecret,
}),
});
return Response.json({
repo: created.name,
remote: created.remote,
commit,
refs: push.refs,
});
},
};

In-memory filesystem helper

Use this helper with isomorphic-git in Workers when you need a short-lived working tree in memory.

src/memory-fs.js
class MemoryStats {
entry;
constructor(entry) {
this.entry = entry;
}
get size() {
return this.entry.kind === "file" ? this.entry.data.byteLength : 0;
}
get mtimeMs() {
return this.entry.mtimeMs;
}
get ctimeMs() {
return this.entry.mtimeMs;
}
get mode() {
return this.entry.kind === "file" ? 0o100644 : 0o040000;
}
isFile() {
return this.entry.kind === "file";
}
isDirectory() {
return this.entry.kind === "dir";
}
isSymbolicLink() {
return false;
}
}
export class MemoryFS {
encoder = new TextEncoder();
decoder = new TextDecoder();
entries = new Map([
["/", { kind: "dir", children: new Set(), mtimeMs: Date.now() }],
]);
promises = {
readFile: this.readFile.bind(this),
writeFile: this.writeFile.bind(this),
unlink: this.unlink.bind(this),
readdir: this.readdir.bind(this),
mkdir: this.mkdir.bind(this),
rmdir: this.rmdir.bind(this),
stat: this.stat.bind(this),
lstat: this.lstat.bind(this),
};
normalize(input) {
const segments = [];
for (const part of input.split("/")) {
if (!part || part === ".") {
continue;
}
if (part === "..") {
segments.pop();
continue;
}
segments.push(part);
}
return `/${segments.join("/")}` || "/";
}
parent(path) {
const normalized = this.normalize(path);
if (normalized === "/") {
return "/";
}
const parts = normalized.split("/").filter(Boolean);
parts.pop();
return parts.length ? `/${parts.join("/")}` : "/";
}
basename(path) {
return this.normalize(path).split("/").filter(Boolean).pop() ?? "";
}
getEntry(path) {
return this.entries.get(this.normalize(path));
}
requireEntry(path) {
const entry = this.getEntry(path);
if (!entry) {
throw new Error(`ENOENT: ${path}`);
}
return entry;
}
requireDir(path) {
const entry = this.requireEntry(path);
if (entry.kind !== "dir") {
throw new Error(`ENOTDIR: ${path}`);
}
return entry;
}
async mkdir(path, options) {
const target = this.normalize(path);
if (target === "/") {
return;
}
const recursive =
typeof options === "object" && options !== null && options.recursive;
const parent = this.parent(target);
if (!this.entries.has(parent)) {
if (!recursive) {
throw new Error(`ENOENT: ${parent}`);
}
await this.mkdir(parent, { recursive: true });
}
if (this.entries.has(target)) {
return;
}
this.entries.set(target, {
kind: "dir",
children: new Set(),
mtimeMs: Date.now(),
});
this.requireDir(parent).children.add(this.basename(target));
}
async writeFile(path, data) {
const target = this.normalize(path);
await this.mkdir(this.parent(target), { recursive: true });
const bytes =
typeof data === "string"
? this.encoder.encode(data)
: data instanceof Uint8Array
? data
: new Uint8Array(data);
this.entries.set(target, {
kind: "file",
data: bytes,
mtimeMs: Date.now(),
});
this.requireDir(this.parent(target)).children.add(this.basename(target));
}
async readFile(path, options) {
const entry = this.requireEntry(path);
if (entry.kind !== "file") {
throw new Error(`EISDIR: ${path}`);
}
const encoding = typeof options === "string" ? options : options?.encoding;
return encoding ? this.decoder.decode(entry.data) : entry.data;
}
async readdir(path) {
return [...this.requireDir(path).children].sort();
}
async unlink(path) {
const target = this.normalize(path);
const entry = this.requireEntry(target);
if (entry.kind !== "file") {
throw new Error(`EISDIR: ${path}`);
}
this.entries.delete(target);
this.requireDir(this.parent(target)).children.delete(this.basename(target));
}
async rmdir(path) {
const target = this.normalize(path);
const entry = this.requireDir(target);
if (entry.children.size > 0) {
throw new Error(`ENOTEMPTY: ${path}`);
}
this.entries.delete(target);
this.requireDir(this.parent(target)).children.delete(this.basename(target));
}
async stat(path) {
return new MemoryStats(this.requireEntry(path));
}
async lstat(path) {
return this.stat(path);
}
}