feat: enable OSC 8 hyperlink clicking with Cmd/Ctrl modifier

lib/ghostty.ts

@@ -605,9 +605,51 @@ export class GhosttyTerminal {
     return this.exports.ghostty_terminal_is_row_wrapped(this.handle, row) !== 0;
   }
 
-  /** Hyperlink URI not yet exposed in simplified API */
-  getHyperlinkUri(_id: number): string | null {
-    return null; // TODO: Add hyperlink support
+  /**
+   * Get the hyperlink URI for a cell at the given position.
+   * @param row Row index (0-based, in active viewport)
+   * @param col Column index (0-based)
+   * @returns The URI string, or null if no hyperlink at that position
+   */
+  getHyperlinkUri(row: number, col: number): string | null {
+    // Check if WASM has this function (requires rebuilt WASM with hyperlink support)
+    if (!this.exports.ghostty_terminal_get_hyperlink_uri) {
+      return null;
+    }
+
+    // Try with initial buffer, retry with larger if needed (for very long URLs)
+    const bufferSizes = [2048, 8192, 32768];
+
+    for (const bufSize of bufferSizes) {
+      const bufPtr = this.exports.ghostty_wasm_alloc_u8_array(bufSize);
+
+      try {
+        const bytesWritten = this.exports.ghostty_terminal_get_hyperlink_uri(
+          this.handle,
+          row,
+          col,
+          bufPtr,
+          bufSize
+        );
+
+        // 0 means no hyperlink at this position
+        if (bytesWritten === 0) return null;
+
+        // -1 means buffer too small, try next size
+        if (bytesWritten === -1) continue;
+
+        // Negative values other than -1 are errors
+        if (bytesWritten < 0) return null;
+
+        const bytes = new Uint8Array(this.memory.buffer, bufPtr, bytesWritten);
+        return new TextDecoder().decode(bytes.slice());
+      } finally {
+        this.exports.ghostty_wasm_free_u8_array(bufPtr, bufSize);
+      }
+    }
+
+    // URI too long even for largest buffer
+    return null;
   }
 
   /**

lib/link-detector.ts

@@ -40,7 +40,6 @@ export class LinkDetector {
    * @returns Link at position, or undefined if none
    */
   async getLinkAt(col: number, row: number): Promise<ILink | undefined> {
-    // First, check if this cell has a hyperlink_id (fast path for OSC 8)
     const line = this.terminal.buffer.active.getLine(row);
     if (!line || col < 0 || col >= line.length) {
       return undefined;
@@ -50,13 +49,11 @@ export class LinkDetector {
     if (!cell) {
       return undefined;
     }
-    const hyperlinkId = cell.getHyperlinkId();
 
-    if (hyperlinkId > 0) {
-      // Fast path: check cache by hyperlink_id
-      const cacheKey = `h${hyperlinkId}`;
-      if (this.linkCache.has(cacheKey)) {
-        return this.linkCache.get(cacheKey);
+    // Check if any cached link contains this position (fast path)
+    for (const link of this.linkCache.values()) {
+      if (this.isPositionInLink(col, row, link)) {
+        return link;
       }
     }
 
@@ -65,14 +62,7 @@ export class LinkDetector {
       await this.scanRow(row);
     }
 
-    // Check cache again (hyperlinkId or position-based)
-    if (hyperlinkId > 0) {
-      const cacheKey = `h${hyperlinkId}`;
-      const link = this.linkCache.get(cacheKey);
-      if (link) return link;
-    }
-
-    // Check if any cached link contains this position
+    // Check cache again after scanning
     for (const link of this.linkCache.values()) {
       if (this.isPositionInLink(col, row, link)) {
         return link;
@@ -109,31 +99,14 @@ export class LinkDetector {
 
   /**
    * Cache a link for fast lookup
+   *
+   * Note: We cache by position range, not hyperlink_id, because the WASM
+   * returns hyperlink_id as a boolean (0 or 1), not a unique identifier.
+   * The actual unique identifier is the URI which is retrieved separately.
    */
   private cacheLink(link: ILink): void {
-    // Try to get hyperlink_id for this link
-    const { start } = link.range;
-    const line = this.terminal.buffer.active.getLine(start.y);
-    if (line) {
-      const cell = line.getCell(start.x);
-      if (!cell) {
-        // Fallback: cache by position range
-        const { start: s, end: e } = link.range;
-        const cacheKey = `r${s.y}:${s.x}-${e.x}`;
-        this.linkCache.set(cacheKey, link);
-        return;
-      }
-      const hyperlinkId = cell.getHyperlinkId();
-
-      if (hyperlinkId > 0) {
-        // Cache by hyperlink_id (best case - stable across rows)
-        this.linkCache.set(`h${hyperlinkId}`, link);
-        return;
-      }
-    }
-
-    // Fallback: cache by position range
-    // Format: r${row}:${startX}-${endX}
+    // Cache by position range - this uniquely identifies links even when
+    // multiple OSC 8 links exist on the same line
     const { start: s, end: e } = link.range;
     const cacheKey = `r${s.y}:${s.x}-${e.x}`;
     this.linkCache.set(cacheKey, link);

lib/providers/osc8-link-provider.ts

@@ -28,7 +28,7 @@ export class OSC8LinkProvider implements ILinkProvider {
    */
   provideLinks(y: number, callback: (links: ILink[] | undefined) => void): void {
     const links: ILink[] = [];
-    const visitedIds = new Set<number>();
+    const visitedPositions = new Set<number>(); // Track which columns we've already processed
 
     const line = this.terminal.buffer.active.getLine(y);
     if (!line) {
@@ -38,26 +38,55 @@ export class OSC8LinkProvider implements ILinkProvider {
 
     // Scan through this line looking for hyperlink_id
     for (let x = 0; x < line.length; x++) {
+      // Skip already processed positions
+      if (visitedPositions.has(x)) continue;
+
       const cell = line.getCell(x);
       if (!cell) continue;
 
       const hyperlinkId = cell.getHyperlinkId();
 
-      // Skip cells without links or already processed links
-      if (hyperlinkId === 0 || visitedIds.has(hyperlinkId)) {
+      // Skip cells without links
+      if (hyperlinkId === 0) {
         continue;
       }
 
-      visitedIds.add(hyperlinkId);
+      // Get the URI from WASM using viewport row and column
+      // The y parameter is a buffer row, but WASM expects a viewport row
+      if (!this.terminal.wasmTerm) continue;
+      const scrollbackLength = this.terminal.wasmTerm.getScrollbackLength();
+      const viewportRow = y - scrollbackLength;
 
-      // Find the full extent of this link (may span multiple lines)
-      const range = this.findLinkRange(hyperlinkId, y, x);
+      // Skip if this row is in scrollback (not in active viewport)
+      if (viewportRow < 0) continue;
 
-      // Get the URI from WASM
-      if (!this.terminal.wasmTerm) continue;
-      const uri = this.terminal.wasmTerm.getHyperlinkUri(hyperlinkId);
+      const uri = this.terminal.wasmTerm.getHyperlinkUri(viewportRow, x);
 
       if (uri) {
+        // Find the end of this link by scanning forward until we hit a cell
+        // without a hyperlink or with a different URI
+        let endX = x;
+        for (let col = x + 1; col < line.length; col++) {
+          const nextCell = line.getCell(col);
+          if (!nextCell || nextCell.getHyperlinkId() === 0) break;
+
+          // Check if this cell has the same URI
+          const nextUri = this.terminal.wasmTerm!.getHyperlinkUri(viewportRow, col);
+          if (nextUri !== uri) break;
+
+          endX = col;
+        }
+
+        // Mark all columns in this link as visited
+        for (let col = x; col <= endX; col++) {
+          visitedPositions.add(col);
+        }
+
+        const range: IBufferRange = {
+          start: { x, y },
+          end: { x: endX, y },
+        };
+
         links.push({
           text: uri,
           range,
@@ -211,6 +240,7 @@ export interface ITerminalForOSC8Provider {
     };
   };
   wasmTerm?: {
-    getHyperlinkUri(id: number): string | null;
+    getHyperlinkUri(row: number, col: number): string | null;
+    getScrollbackLength(): number;
   };
 }

lib/types.ts

@@ -460,6 +460,15 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
   ): number; // Returns codepoint count or -1 on error
   ghostty_terminal_is_row_wrapped(terminal: TerminalHandle, row: number): number;
 
+  // Hyperlink API
+  ghostty_terminal_get_hyperlink_uri(
+    terminal: TerminalHandle,
+    row: number,
+    col: number,
+    bufPtr: number,
+    bufLen: number
+  ): number; // Returns bytes written, 0 if no hyperlink, -1 on error
+
   // Response API (for DSR and other terminal queries)
   ghostty_terminal_has_response(terminal: TerminalHandle): boolean;
   ghostty_terminal_read_response(terminal: TerminalHandle, bufPtr: number, bufLen: number): number; // Returns bytes written, 0 if no response, -1 on error