captcha-sdk 0.0.1

# captcha-sdk

Unified server-side CAPTCHA verification for Rust.

`captcha-sdk` provides one provider-independent request, result, error model,
and verifier trait for Cloudflare Turnstile, hCaptcha, Google reCAPTCHA,
Friendly Captcha, CaptchaFox, MTCaptcha, Prosopo Procaptcha, and ALTCHA.

> Status: `0.1.0` is the initial API scaffold. The normalized core and provider
> configuration modules are present; provider HTTP adapters are not implemented
> yet. The proposed replacement API is documented as
> [TARGET architecture / implementation pending](docs/architecture/README.md);
> it does not describe the current ABI.

## Features

- `turnstile` — Cloudflare Turnstile adapter scaffold
- `hcaptcha` — hCaptcha adapter scaffold
- `recaptcha` — Google reCAPTCHA adapter scaffold
- `friendlycaptcha` — Friendly Captcha v2 adapter scaffold
- `captchafox` — CaptchaFox adapter scaffold
- `mtcaptcha` — MTCaptcha adapter scaffold
- `procaptcha` — Prosopo Procaptcha adapter scaffold
- `prosopo` — alias that enables `procaptcha`
- `altcha` — ALTCHA local HMAC verification scaffold
- `all-providers` — enables every provider module

No provider is enabled by default.

```toml
[dependencies]
captcha-sdk = { version = "0.1", features = ["turnstile"] }
```

## Current scaffold API

```rust
use captcha_sdk::{FailureReason, Provider, VerificationResult};

let result = VerificationResult::invalid(
    Provider::Turnstile,
    vec![FailureReason::ActionMismatch],
);

assert!(!result.valid);
assert_eq!(result.provider, Provider::Turnstile);
```

This example describes only the current `0.1.0` scaffold. Its closed `Provider`
enum and bool-based `VerificationResult` are not the intended long-term
contract. See the [target architecture](docs/architecture/README.md) for the
planned `ProviderId`, `ProviderVerdict`, evidence, policy, capabilities, and
third-party adapter model.

## Development

```bash
cargo fmt --all --check
cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
cargo test --workspace --all-features --locked
```

For the configured nextest runner:

```bash
cargo install cargo-nextest --locked
cargo nextest run --all-features
```

## License

Licensed under the MIT License.