url-shortner-go-wasm

a url shortener written in go, compiled to webassembly, running on cloudflare workers. uses cloudflare workers kv for storage and crc32 for generating short ids.

architecture

request → cloudflare worker (typescript) → go wasm module → cloudflare kv

the typescript entrypoint handles routing and auth. the go module, compiled to wasm via goos=js goarch=wasm, exposes two functions on globalthis through syscall/js:

• createshorturl(url) — crc32 hashes the url, writes the mapping to kv, returns the checksum
• getredirecturl(id) — looks up the original url from kv by checksum

both return javascript promises wrapping async go routines. the go wasm runtime is initialized via wasm_exec.js with environment variables passed at instantiation.

api

post / — shorten a url

curl -X POST https://s.prdai.dev \
  -H "Content-Type: application/json" \
  -H "Authorization: <auth_secret>" \
  -d '{"Url": "https://www.google.com/"}'

{ "redirecturl": "https://s.prdai.dev/2743104607" }

get /:id — redirect

returns a 301 redirect to the original url.

stack

component	role
go 1.25+	core logic, compiled to wasm
syscall/js	go ↔ js bridge
wasm_exec.js	go wasm runtime (from go team, customized to pass env vars)
cloudflare workers	runtime
cloudflare kv	key-value storage
crc32	url → short id generation
typescript	worker entrypoint

setup

prerequisites

• go 1.25+
• bun
• just
• cloudflare account with a kv namespace

install

git clone https://github.com/prdai/url-shortner-go-wasm.git
cd url-shortner-go-wasm
bun i
go mod download

configure

cp .env.example .env

set cloudflare_account_id, cloudflare_namespace_id, cloudflare_api_token, and auth_secret.

development

just dev

compiles go to wasm/main.wasm and starts wrangler dev.

deploy

bun run deploy

performance

typical latency for successful requests:

• redirect: ~275ms (p50), ~590ms (p95)
• create: ~380ms (p50), ~615ms (p95)

license

mit