diff --git a/interface/src/main/java/xsbti/CompileFailed.java b/interface/src/main/java/xsbti/CompileFailed.java
index bb5b2a93a..f1cbbc61b 100644
--- a/interface/src/main/java/xsbti/CompileFailed.java
+++ b/interface/src/main/java/xsbti/CompileFailed.java
@@ -3,4 +3,5 @@ package xsbti;
 public abstract class CompileFailed extends RuntimeException
 {
 	public abstract String[] arguments();
+	public abstract Problem[] problems();
 }
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Maybe.java b/interface/src/main/java/xsbti/Maybe.java
new file mode 100644
index 000000000..f730ef918
--- /dev/null
+++ b/interface/src/main/java/xsbti/Maybe.java
@@ -0,0 +1,30 @@
+/* sbt -- Simple Build Tool
+ * Copyright 2008, 2009, 2010  Mark Harrah
+ */
+package xsbti;
+
+/** Intended as a lightweight carrier for scala.Option. */
+public abstract class Maybe<t>
+{
+	// private pending Scala bug #3642
+	protected Maybe() {}
+
+	public static <s> Maybe<s> just(final s v)
+	{
+		return new Maybe<s>() {
+			public boolean isDefined() { return true; }
+			public s get() { return v; }
+		};
+	}
+	public static <s> Maybe<s> nothing()
+	{
+		return new Maybe<s>() {
+			public boolean isDefined() { return false; }
+			public s get() { throw new UnsupportedOperationException("nothing.get"); }
+		};
+	}
+
+	public final boolean isEmpty() { return !isDefined(); }
+	public abstract boolean isDefined();
+	public abstract t get();
+}
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Position.java b/interface/src/main/java/xsbti/Position.java
new file mode 100644
index 000000000..96c60ebb2
--- /dev/null
+++ b/interface/src/main/java/xsbti/Position.java
@@ -0,0 +1,18 @@
+/* sbt -- Simple Build Tool
+ * Copyright 2008, 2009, 2010  Mark Harrah
+ */
+package xsbti;
+
+public interface Position
+{
+	Maybe<Integer> line();
+	String lineContent();
+	Maybe<Integer> offset();
+
+	// pointer to the column position of the error/warning
+	Maybe<Integer> pointer();
+	Maybe<String> pointerSpace();
+
+	Maybe<String> sourcePath();
+	Maybe<java.io.File> sourceFile();	
+}
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Problem.java b/interface/src/main/java/xsbti/Problem.java
new file mode 100644
index 000000000..cf2641900
--- /dev/null
+++ b/interface/src/main/java/xsbti/Problem.java
@@ -0,0 +1,11 @@
+/* sbt -- Simple Build Tool
+ * Copyright 2008, 2009, 2010  Mark Harrah
+ */
+package xsbti;
+
+public interface Problem
+{
+	Severity severity();
+	String message();
+	Position position();
+}
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Reporter.java b/interface/src/main/java/xsbti/Reporter.java
new file mode 100644
index 000000000..8556cbe8a
--- /dev/null
+++ b/interface/src/main/java/xsbti/Reporter.java
@@ -0,0 +1,20 @@
+/* sbt -- Simple Build Tool
+ * Copyright 2008, 2009, 2010  Mark Harrah
+ */
+package xsbti;
+
+public interface Reporter
+{
+	/** Resets logging, including any accumulated errors, warnings, messages, and counts.*/
+	public void reset();
+	/** Returns true if this logger has seen any errors since the last call to reset.*/
+	public boolean hasErrors();
+	/** Returns true if this logger has seen any warnings since the last call to reset.*/
+	public boolean hasWarnings();
+	/** Logs a summary of logging since the last reset.*/
+	public void printSummary();
+	/** Returns a list of warnings and errors since the last reset.*/
+	public Problem[] problems();
+	/** Logs a message.*/
+	public void log(Position pos, String msg, Severity sev);
+}
\ No newline at end of file
diff --git a/interface/src/main/java/xsbti/Severity.java b/interface/src/main/java/xsbti/Severity.java
new file mode 100644
index 000000000..09aed574b
--- /dev/null
+++ b/interface/src/main/java/xsbti/Severity.java
@@ -0,0 +1,9 @@
+/* sbt -- Simple Build Tool
+ * Copyright 2008, 2009, 2010  Mark Harrah
+ */
+package xsbti;
+
+public enum Severity
+{
+	Info, Warn, Error
+}
\ No newline at end of file