kafka

A privacy-respecting, open metasearch engine written in Go. SearXNG-compatible API with an HTML frontend, designed to be fast, lightweight, and deployable anywhere.

9 engines. No JavaScript. No tracking. One binary.

Features

• SearXNG-compatible API — drop-in replacement for existing integrations
• 9 search engines — Wikipedia, arXiv, Crossref, Brave, Qwant, DuckDuckGo, GitHub, Reddit, Bing
• HTML frontend — HTMX + Go templates with instant search, dark mode, responsive design
• Valkey cache — optional Redis-compatible caching with configurable TTL
• Rate limiting — three layers: per-IP, burst, and global (all disabled by default)
• CORS — configurable origins for browser-based clients
• OpenSearch — browsers can add kafka as a search engine from the address bar
• Graceful degradation — individual engine failures don't kill the whole search
• Docker — multi-stage build, ~20MB runtime image
• NixOS — native NixOS module with systemd service

Quick Start

Binary

git clone https://git.ashisgreat.xyz/penal-colony/gosearch.git
cd kafka
go build ./cmd/kafka
./kafka -config config.toml

Docker Compose

cp config.example.toml config.toml
# Edit config.toml — set your Brave API key, etc.
docker compose up -d

NixOS

Add to your flake inputs:

inputs.kafka.url = "git+https://git.ashisgreat.xyz/penal-colony/gosearch.git";

Enable in your configuration:

imports = [ inputs.kafka.nixosModules.default ];

services.kafka = {
  enable = true;
  openFirewall = true;
  baseUrl = "https://search.example.com";
  # config = "/etc/kafka/config.toml";  # default
};

Write your config:

sudo mkdir -p /etc/kafka
sudo cp config.example.toml /etc/kafka/config.toml
sudo $EDITOR /etc/kafka/config.toml

Deploy:

sudo nixos-rebuild switch --flake .#

Nix Development Shell

nix develop
go test ./...
go run ./cmd/kafka -config config.toml

Endpoints

Endpoint	Description
GET /	HTML search page
GET /search?q=…&format=html	HTML results (full page or HTMX fragment)
GET/POST /search	JSON/CSV/RSS results
GET /opensearch.xml	OpenSearch description XML
GET /healthz	Health check
GET /static/*	Embedded CSS, images, favicon

Search API

Parameters

Parameter	Default	Description
q	—	Search query (required)
format	json	json, csv, rss, html
pageno	1	Page number
safesearch	0	Safe search level (0–2)
time_range	—	day, week, month, year
language	auto	BCP-47 language code
engines	all	Comma-separated engine names

Example

curl "http://localhost:8080/search?q=golang&format=json&engines=github,duckduckgo"

Response (JSON)

{
  "query": "golang",
  "number_of_results": 14768,
  "results": [
    {
      "title": "The Go Programming Language",
      "url": "https://go.dev/",
      "content": "Go is an open source programming language...",
      "engine": "duckduckgo",
      "score": 1.0,
      "type": "result"
    }
  ],
  "suggestions": ["golang tutorial", "golang vs rust"],
  "unresponsive_engines": []
}

Configuration

Copy config.example.toml to config.toml and edit. All settings can also be overridden via environment variables (listed in the example file).

Key Sections

• [server] — port, timeout, public base URL for OpenSearch
• [upstream] — optional upstream metasearch proxy for unported engines
• [engines] — which engines run locally, engine-specific settings
• [cache] — Valkey/Redis address, password, TTL
• [cors] — allowed origins and methods
• [rate_limit] — per-IP sliding window (30 req/min default)
• [global_rate_limit] — server-wide limit (disabled by default)
• [burst_rate_limit] — per-IP burst + sustained windows (disabled by default)

Environment Variables

Variable	Description
PORT	Listen port (default: 8080)
BASE_URL	Public URL for OpenSearch XML
UPSTREAM_SEARXNG_URL	Upstream instance URL
LOCAL_PORTED_ENGINES	Comma-separated local engine list
HTTP_TIMEOUT	Upstream request timeout
BRAVE_API_KEY	Brave Search API key
BRAVE_ACCESS_TOKEN	Gate requests with token
VALKEY_ADDRESS	Valkey/Redis address
VALKEY_PASSWORD	Valkey/Redis password
VALKEY_CACHE_TTL	Cache TTL

See config.example.toml for the full list including rate limiting and CORS variables.

Engines

Engine	Source	Notes
Wikipedia	MediaWiki API	General knowledge
arXiv	arXiv API	Academic papers
Crossref	Crossref API	Academic metadata
Brave	Brave Search API	General web (requires API key)
Qwant	Qwant Lite HTML	General web
DuckDuckGo	DDG Lite HTML	General web
GitHub	GitHub Search API v3	Code and repositories
Reddit	Reddit JSON API	Discussions
Bing	Bing RSS	General web

Engines not listed in engines.local_ported are proxied to an upstream metasearch instance if upstream.url is configured.

Architecture

┌─────────────────────────────────────┐
│           HTTP Handler              │
│  /search  /  /opensearch.xml       │
├─────────────────────────────────────┤
│         Middleware Chain             │
│  Global → Burst → Per-IP → CORS    │
├─────────────────────────────────────┤
│         Search Service              │
│  Parallel engine execution          │
│  WaitGroup + graceful degradation   │
├─────────────────────────────────────┤
│           Cache Layer               │
│  Valkey/Redis (optional, no-op if   │
│  unconfigured)                      │
├─────────────────────────────────────┤
│          Engines (×9)               │
│  Each runs in its own goroutine     │
│  Failures → unresponsive_engines    │
└─────────────────────────────────────┘

Docker

The Dockerfile uses a multi-stage build:

# Build stage: golang:1.24-alpine
# Runtime stage: alpine:3.21 (~20MB)
# CGO_ENABLED=0 — static binary

docker compose up -d

Includes Valkey 8 with health checks out of the box.

License

AGPLv3