Feature Flags

All optional capabilities in kumo are behind feature flags, so you only compile what you need.

Reference Table

Flag	Pulls in	Purpose
(default)	—	CSS + regex selectors, all file stores, all middleware, HTTP cache, link extractor
`derive`	`kumo-derive`	`#[derive(Extract)]` for zero-boilerplate CSS extraction
`jsonpath`	`jsonpath-rust`	JSONPath selector on `Response`
`xpath`	`sxd-xpath`	XPath selector on `Response`
`browser`	`chromiumoxide`	Headless Chromium fetcher for JS-rendered pages
`stealth`	`rquest`, `rquest-util`	TLS/HTTP2 fingerprint spoofing + browser stealth patches¹
`claude`	`rig-core`	`AnthropicClient` for LLM extraction
`openai`	`rig-core`	`OpenAiClient` for LLM extraction
`gemini`	`rig-core`	`GeminiClient` for LLM extraction
`ollama`	`rig-core`	`OllamaClient` for local LLM extraction
`llm`	`rig-core`, `schemars`	Base LLM traits (implied by all provider flags)
`postgres`	`sqlx`	`PostgresStore`
`sqlite`	`sqlx`	`SqliteStore`
`mysql`	`sqlx`	`MySqlStore`
`persistence`	—	`FileFrontier` — file-backed URL frontier that survives restarts
`redis-frontier`	`redis`	`RedisFrontier` — distributed URL frontier via Redis
`otel`	`opentelemetry`, `opentelemetry_sdk`, `opentelemetry-otlp`, `tracing-opentelemetry`	OTLP/gRPC export of all spans and events

¹ The stealth feature compiles BoringSSL from source. It requires cmake and nasm on the build machine. See Stealth Mode for setup instructions.

Common Combinations

Data science / scripting

kumo = { version = "0.1", features = ["sqlite", "derive"] }

Production crawl

kumo = { version = "0.1", features = ["postgres", "redis-frontier", "otel"] }

LLM extraction

# Cloud provider
kumo = { version = "0.1", features = ["claude"] }

# Local model
kumo = { version = "0.1", features = ["ollama"] }

Full-stack

kumo = { version = "0.1", features = [
    "derive", "xpath", "jsonpath",
    "browser", "stealth",
    "claude",
    "postgres", "redis-frontier",
    "otel",
] }