voidcrawl_mcp/

server.rs

//! Top-level MCP service. Owns `AppState` and the `ToolRouter`.
//!
//! Each tool method is a thin adapter that delegates to a free
//! function in `crate::tools::*`; the heavy lifting lives there so
//! this file stays focused on wire-protocol concerns.

use std::sync::Arc;

use rmcp::{
    ErrorData,
    handler::server::{
        ServerHandler,
        router::tool::ToolRouter,
        wrapper::{Json, Parameters},
    },
    model::{CallToolResult, Implementation, ProtocolVersion, ServerCapabilities, ServerInfo},
    tool, tool_handler, tool_router,
};

use crate::{
    errors::map_err,
    state::AppState,
    tools,
    tools::{
        actions::{
            AxTreeArgs, AxTreeResult, CaptureCaptchaResult, ClickArgs, ClickByRoleArgs,
            ClickVisualCoordsArgs, DetectCaptchaResult, EvalJsArgs, EvalJsResult, ExtractArgs,
            ExtractResult, InjectCaptchaTokenArgs, NetworkCaptureResult, OkResult,
            SessionIdArgs as ActionSessionIdArgs, SolveCaptchaArgs, SolveCaptchaResult,
            TeleportArgs, TitleResult, TypeTextArgs, WaitIdleArgs,
        },
        fetch::{FetchArgs, FetchManyArgs, FetchManyResult, FetchResult},
        introspect::PoolStatus,
        screenshot::ScreenshotArgs,
        session::{
            SessionCloseResult, SessionContentResult, SessionIdArgs, SessionNavigateArgs,
            SessionNavigateResult, SessionOpenArgs, SessionOpenResult,
        },
    },
};

/// The MCP service struct. Cheap to `Arc`-share.
#[derive(Debug)]
pub struct VoidCrawlServer {
    state:       Arc<AppState>,
    #[allow(dead_code, reason = "read by the `#[tool_handler]` macro expansion")]
    tool_router: ToolRouter<Self>,
}

impl VoidCrawlServer {
    pub fn new(state: Arc<AppState>) -> Self {
        Self { state, tool_router: Self::tool_router() }
    }

    pub fn state(&self) -> &AppState {
        &self.state
    }
}

#[tool_router]
impl VoidCrawlServer {
    #[tool(
        name = "fetch",
        description = "Fetch a URL with stealth headless Chrome and return HTML + metadata. \
Use for single-shot scrapes; for bulk use fetch_many."
    )]
    pub async fn fetch(
        &self,
        Parameters(args): Parameters<FetchArgs>,
    ) -> Result<Json<FetchResult>, ErrorData> {
        tools::fetch::run(self, args).await.map(Json).map_err(map_err)
    }

    #[tool(
        name = "fetch_many",
        description = "Fetch many URLs in parallel over the shared browser pool. Returns \
one entry per request in input order; per-request errors do not abort the batch. \
Each result carries `waited_ms` (time queued for a tab), and the batch carries a \
`pool` summary {max_tabs, submitted, queued, max_waited_ms, note} — if `queued > 0` \
you oversubscribed the pool; cap batches at `max_tabs` (see pool_status) for full parallelism."
    )]
    pub async fn fetch_many(
        &self,
        Parameters(args): Parameters<FetchManyArgs>,
    ) -> Result<Json<FetchManyResult>, ErrorData> {
        Ok(Json(tools::fetch::run_many(self, args).await))
    }

    #[tool(
        name = "screenshot",
        description = "Load a URL in stealth headless Chrome and return a full-page PNG."
    )]
    pub async fn screenshot(
        &self,
        Parameters(args): Parameters<ScreenshotArgs>,
    ) -> Result<CallToolResult, ErrorData> {
        tools::screenshot::run(self, args).await
    }

    #[tool(
        name = "session_open",
        description = "Open a new stateful browser session with a dedicated Chrome instance. \
Returns a session_id used by session_navigate / session_content / session_close. \
Pass `user_data_dir` to mount a persistent profile (e.g. one already logged into LinkedIn); \
omit it for an ephemeral cookieless profile. Set `headful=true` to bring up a visible window \
(useful for a one-time manual login into the persistent profile)."
    )]
    pub async fn session_open(
        &self,
        Parameters(args): Parameters<SessionOpenArgs>,
    ) -> Result<Json<SessionOpenResult>, ErrorData> {
        tools::session::open(self, args).await.map(Json)
    }

    #[tool(
        name = "session_navigate",
        description = "Navigate the given session to a URL and wait for it to settle. \
wait_for accepts 'networkidle' (default) or 'selector:<css>' (event-driven, no polling)."
    )]
    pub async fn session_navigate(
        &self,
        Parameters(args): Parameters<SessionNavigateArgs>,
    ) -> Result<Json<SessionNavigateResult>, ErrorData> {
        tools::session::navigate(self, args).await.map(Json)
    }

    #[tool(
        name = "session_content",
        description = "Return the current HTML, title, and URL of the given session's page."
    )]
    pub async fn session_content(
        &self,
        Parameters(args): Parameters<SessionIdArgs>,
    ) -> Result<Json<SessionContentResult>, ErrorData> {
        tools::session::content(self, args).await.map(Json)
    }

    #[tool(
        name = "session_close",
        description = "Close the given session: shut down its Chrome instance and free resources. \
Always call this when you're done — otherwise the browser stays alive until the server exits."
    )]
    pub async fn session_close(
        &self,
        Parameters(args): Parameters<SessionIdArgs>,
    ) -> Result<Json<SessionCloseResult>, ErrorData> {
        tools::session::close(self, args).await.map(Json)
    }

    #[tool(
        name = "pool_status",
        description = "Report the browser pool configuration plus a live snapshot of \
concurrency: `max_tabs`, `available` (free slots right now), `in_flight`, and \
`sessions_open`. Read `available` before a big fan-out to size the batch."
    )]
    pub async fn pool_status(&self) -> Result<Json<PoolStatus>, ErrorData> {
        tools::introspect::pool_status(self).await.map(Json).map_err(map_err)
    }

    #[tool(
        name = "click",
        description = "Click the first element matching a CSS selector in an open session."
    )]
    pub async fn click(
        &self,
        Parameters(args): Parameters<ClickArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::click(self, args).await.map(Json)
    }

    #[tool(
        name = "teleport",
        description = "Override the session's geolocation (and optionally timezone + locale) so \
navigator.geolocation and location-aware sites resolve to the given lat/lon — 'teleport' the \
browser. The geolocation permission is granted automatically. Call after session_open and \
BEFORE navigating; the override persists across navigations. For Google Maps 'near me' queries: \
use a FRESH session per location, and navigate to the search twice (prime + read) — Maps resolves \
location on first load and applies it on the next request."
    )]
    pub async fn teleport(
        &self,
        Parameters(args): Parameters<TeleportArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::teleport(self, args).await.map(Json)
    }

    #[tool(
        name = "click_visual_coords",
        description = "Click at pixel coordinates (x, y) in CSS pixels. Use when selector-based \
clicks fail silently (React forms that ignore dispatchEvent clicks). Coords are pre-DPR: \
divide screenshot pixels by devicePixelRatio on HiDPI."
    )]
    pub async fn click_visual_coords(
        &self,
        Parameters(args): Parameters<ClickVisualCoordsArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::click_visual_coords(self, args).await.map(Json)
    }

    #[tool(
        name = "type_text",
        description = "Type text into an input. With `selector`, focuses + types. Without, \
dispatches keys to whatever currently has focus (pair with click_visual_coords first)."
    )]
    pub async fn type_text(
        &self,
        Parameters(args): Parameters<TypeTextArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::type_text(self, args).await.map(Json)
    }

    #[tool(
        name = "eval_js",
        description = "Evaluate a JS expression in the session's page. Returns the value as JSON."
    )]
    pub async fn eval_js(
        &self,
        Parameters(args): Parameters<EvalJsArgs>,
    ) -> Result<Json<EvalJsResult>, ErrorData> {
        tools::actions::eval_js(self, args).await.map(Json)
    }

    #[tool(name = "title", description = "Return the current document title of the session.")]
    pub async fn title(
        &self,
        Parameters(args): Parameters<ActionSessionIdArgs>,
    ) -> Result<Json<TitleResult>, ErrorData> {
        tools::actions::title(self, args).await.map(Json)
    }

    #[tool(
        name = "extract",
        description = "Run document.querySelectorAll(selector) and return each element's text content."
    )]
    pub async fn extract(
        &self,
        Parameters(args): Parameters<ExtractArgs>,
    ) -> Result<Json<ExtractResult>, ErrorData> {
        tools::actions::extract(self, args).await.map(Json)
    }

    #[tool(
        name = "session_ax_tree",
        description = "Return the page's accessibility (AX) tree — the semantic view assistive \
tech sees, with implicit roles resolved, accessible names computed, and hidden nodes pruned. \
Default `mode=compact` gives a pruned, indented role/name outline for reading; `mode=raw` gives \
full CDP nodes. `named_count` vs `node_count` signals AX richness: when low, fall back to HTML, \
screenshot, or CSS selectors. Complements (does not replace) the DOM/visual tools."
    )]
    pub async fn session_ax_tree(
        &self,
        Parameters(args): Parameters<AxTreeArgs>,
    ) -> Result<Json<AxTreeResult>, ErrorData> {
        tools::actions::ax_tree(self, args).await.map(Json)
    }

    #[tool(
        name = "click_by_role",
        description = "Click an element by its accessibility role + accessible name (e.g. \
role=\"button\", name=\"Load more\") instead of a CSS selector. More durable across redesigns, \
but flakier when names are ambiguous, localized, or duplicated — pair with session_ax_tree to \
see available roles/names, and fall back to `click` (CSS) or `click_visual_coords` when it fails."
    )]
    pub async fn click_by_role(
        &self,
        Parameters(args): Parameters<ClickByRoleArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::click_by_role(self, args).await.map(Json)
    }

    #[tool(
        name = "wait_for_network_idle",
        description = "Wait for Chrome's network-idle lifecycle event. Event-driven, no polling."
    )]
    pub async fn wait_for_network_idle(
        &self,
        Parameters(args): Parameters<WaitIdleArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::wait_for_network_idle(self, args).await.map(Json)
    }

    #[tool(
        name = "network_capture",
        description = "Return the Resource Timing entries (URL, initiator type, transfer size, duration) \
observed since the session's most recent navigation. Backed by performance.getEntriesByType('resource')."
    )]
    pub async fn network_capture(
        &self,
        Parameters(args): Parameters<ActionSessionIdArgs>,
    ) -> Result<Json<NetworkCaptureResult>, ErrorData> {
        tools::actions::network_capture(self, args).await.map(Json)
    }

    #[tool(
        name = "solve_captcha",
        description = "Click the Turnstile / reCAPTCHA-v2 / hCaptcha checkbox in an open session \
using real CDP mouse events (not JS click — widgets detect that) and wait for the response \
token to appear. Returns the kind detected, the coordinates clicked, the token value (once \
the widget writes it into its hidden input), and a `solved` flag. No-op (solved=true) when \
the page has no captcha. Only handles widgets whose anchor frame is already visible — if \
detect_captcha reports `turnstile` because the runtime loaded but no widget mounted, trigger \
the form submit that mounts the widget first."
    )]
    pub async fn solve_captcha(
        &self,
        Parameters(args): Parameters<SolveCaptchaArgs>,
    ) -> Result<Json<SolveCaptchaResult>, ErrorData> {
        tools::actions::solve_captcha(self, args).await.map(Json)
    }

    #[tool(
        name = "detect_captcha",
        description = "Probe the DOM for captcha / bot-wall markers. Returns the kind tag \
(recaptcha, hcaptcha, turnstile, cloudflare_challenge, datadome) or null."
    )]
    pub async fn detect_captcha(
        &self,
        Parameters(args): Parameters<ActionSessionIdArgs>,
    ) -> Result<Json<DetectCaptchaResult>, ErrorData> {
        tools::actions::detect_captcha_tool(self, args).await.map(Json)
    }

    #[tool(
        name = "capture_captcha",
        description = "Deep structured probe of a captcha challenge. Returns kind, sitekey, \
widget rect + selector, response-field selector, existing token (if already solved), page URL, \
and Turnstile action/cdata attrs. Use this to hand off to a third-party solver API \
(2Captcha / CapSolver / Anti-Captcha) or a human-in-the-loop flow, then call \
`inject_captcha_token` with the resulting token."
    )]
    pub async fn capture_captcha(
        &self,
        Parameters(args): Parameters<ActionSessionIdArgs>,
    ) -> Result<Json<CaptureCaptchaResult>, ErrorData> {
        tools::actions::capture_captcha_tool(self, args).await.map(Json)
    }

    #[tool(
        name = "inject_captcha_token",
        description = "Write a solved captcha token into the page's hidden response field and \
fire input/change events so React-controlled forms pick it up. For Turnstile, invokes any \
registered `data-callback` function. `kind` defaults to whatever is currently detected; pass \
explicitly ('turnstile'/'recaptcha'/'hcaptcha') to skip re-detection."
    )]
    pub async fn inject_captcha_token(
        &self,
        Parameters(args): Parameters<InjectCaptchaTokenArgs>,
    ) -> Result<Json<OkResult>, ErrorData> {
        tools::actions::inject_captcha_token_tool(self, args).await.map(Json)
    }
}

#[tool_handler]
impl ServerHandler for VoidCrawlServer {
    fn get_info(&self) -> ServerInfo {
        let mut info = ServerInfo::default();
        info.protocol_version = ProtocolVersion::default();
        info.capabilities = ServerCapabilities::builder().enable_tools().build();
        info.server_info = {
            let mut imp = Implementation::default();
            imp.name = "voidcrawl-mcp".into();
            imp.version = env!("CARGO_PKG_VERSION").into();
            imp
        };
        // Shipped to EVERY MCP client on connect (Claude, opencode, Codex,
        // Cursor, Cline, Zed, …), so the AX-first workflow + gotchas reach
        // hosts that have no skill-file mechanism. Keep this condensed; the
        // full guide is .claude/skills/voidcrawl/SKILL.md.
        info.instructions = Some(
            "Stealthy headless Chrome over a shared, fingerprint-patched tab pool — a drop-in \
replacement for Playwright / Chromium MCP.\n\n\
WORKFLOW. Stateless scrape: `fetch` (one URL) or `fetch_many` (parallel; returns \
{results:[{ok,result,error}]} in input order — per-item errors don't abort the batch, and \
status_code is nested under each item's `result`). Stateful flows (login, pagination, clicking): \
`session_open` → `session_navigate` → … → `session_close`. ALWAYS session_close; sessions are \
cookie-isolated.\n\n\
PERCEIVE → ACT → EXTRACT. To see a page, call `session_ax_tree` — a compact role/name outline, \
far cheaper than HTML (don't dump raw HTML to reason over a page). If `named_count` is low vs \
`node_count` the accessibility tree is thin; fall back to `screenshot`. To click: `click` (CSS \
selector) or `click_by_role` (accessibility role + accessible name — durable across redesigns); \
last resort `click_visual_coords` for React forms that ignore synthetic clicks. To extract data, \
run `extract` / `eval_js` with a JS expression and return data, not markup.\n\n\
GOTCHAS. `click_by_role` name matching is EXACT (case + whitespace) — read the exact name from \
`session_ax_tree` first; use `nth` for duplicates. After an in-page (SPA) click, \
`wait_for_network_idle` may run to its full timeout — pass a short `timeout_secs` or use \
`wait_for:\"selector:<css>\"`. On a captcha error, surface it and rotate proxy/profile; don't \
retry the same URL and don't try to solve."
                .into(),
        );
        info
    }
}