diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java
index 11d6f8a08..2124cd14e 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java
@@ -10,6 +10,27 @@ import java.util.TreeMap;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+/**
+ * A BDF dictionary contains zero or more key-value pairs, where the keys
+ * are strings and the values are BDF objects, which may be primitive types
+ * (null, boolean, integer, float, string, raw) or nested containers (list,
+ * dictionary).
+ * <p>
+ * Note that a BDF integer has the same range as a Java long, while a BDF
+ * float has the same range as a Java double. Method names in this class
+ * correspond to the Java types.
+ * <p>
+ * The getX() methods throw {@link FormatException} if the specified key is
+ * absent, the value is null, or the value does not have the requested type.
+ * <p>
+ * The getOptionalX() methods return null if the specified key is absent or
+ * the value is null, or throw {@link FormatException} if the value does not
+ * have the requested type.
+ * <p>
+ * The getX() methods that take a default value return the default value if
+ * the specified key is absent or the value is null, or throw
+ * {@link FormatException} if the value does not have the requested type.
+ */
 @NotThreadSafe
 public final class BdfDictionary extends TreeMap<String, Object> {
 
@@ -80,12 +101,33 @@ public final class BdfDictionary extends TreeMap<String, Object> {
 		return value == null ? defaultValue : value;
 	}
 
+	/**
+	 * Returns the integer with the specified key.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getLong(key).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if there is no value at the specified key,
+	 * or if the value is null or cannot be represented as a Java int.
+	 */
 	public Integer getInt(String key) throws FormatException {
 		Integer value = getOptionalInt(key);
 		if (value == null) throw new FormatException();
 		return value;
 	}
 
+	/**
+	 * Returns the integer with the specified key, or null if the key is
+	 * absent or the value is null.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getOptionalLong(key).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if the value at the specified key is not null
+	 * and cannot be represented as a Java int.
+	 */
 	@Nullable
 	public Integer getOptionalInt(String key) throws FormatException {
 		Long value = getOptionalLong(key);
@@ -96,6 +138,17 @@ public final class BdfDictionary extends TreeMap<String, Object> {
 		return value.intValue();
 	}
 
+	/**
+	 * Returns the integer with the specified key, or the given default
+	 * value if the key is absent or the value is null.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getLong(key, defaultValue).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if the value at the specified key is not null
+	 * and cannot be represented as a Java int.
+	 */
 	public Integer getInt(String key, Integer defaultValue)
 			throws FormatException {
 		Integer value = getOptionalInt(key);
diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfEntry.java b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfEntry.java
index 3fb4b2678..42b52fc2e 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfEntry.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfEntry.java
@@ -6,6 +6,11 @@ import java.util.Map.Entry;
 
 import javax.annotation.concurrent.Immutable;
 
+/**
+ * A convenience class for building {@link BdfDictionary BdfDictionaries}
+ * via the {@link BdfDictionary#of(Entry[]) factory method}. Entries in
+ * BdfDictionaries do not have to be BdfEntries.
+ */
 @Immutable
 @NotNullByDefault
 public class BdfEntry implements Entry<String, Object>, Comparable<BdfEntry> {
diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java
index 6ba6747cc..bce11b079 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java
@@ -12,6 +12,29 @@ import javax.annotation.concurrent.NotThreadSafe;
 
 import static org.briarproject.bramble.api.data.BdfDictionary.NULL_VALUE;
 
+/**
+ * A BDF list contains zero or more BDF objects, which may be primitive types
+ * (null, boolean, integer, float, string, raw) or nested containers (list,
+ * dictionary).
+ * <p>
+ * Note that a BDF integer has the same range as a Java long, while a BDF
+ * float has the same range as a Java double. Method names in this class
+ * correspond to the Java types.
+ * <p>
+ * The getX() methods throw {@link FormatException} if the object at the
+ * specified index is null or does not have the requested type.
+ * <p>
+ * The getOptionalX() methods return null if the object at the specified
+ * index is null, or throw {@link FormatException} if the object does not
+ * have the requested type.
+ * <p>
+ * The getX() methods that take a default value return the default value if
+ * the object at the specified index is null, or throw
+ * {@link FormatException} if the object does not have the requested type.
+ * <p>
+ * All of the getters throw {@link FormatException} if the specified index is
+ * out of range.
+ */
 @NotThreadSafe
 public final class BdfList extends ArrayList<Object> {
 
@@ -82,12 +105,34 @@ public final class BdfList extends ArrayList<Object> {
 		return value == null ? defaultValue : value;
 	}
 
+	/**
+	 * Returns the integer at the specified index.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getLong(index).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if the index is out of range, or if the
+	 * value at the specified index is null or cannot be represented as a
+	 * Java int.
+	 */
 	public Integer getInt(int index) throws FormatException {
 		Integer value = getOptionalInt(index);
 		if (value == null) throw new FormatException();
 		return value;
 	}
 
+	/**
+	 * Returns the integer at the specified index, or null if the object at
+	 * the specified index is null.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getOptionalLong(index).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if the index is out of range, or if the value
+	 * at the specified index cannot be represented as a Java int.
+	 */
 	@Nullable
 	public Integer getOptionalInt(int index) throws FormatException {
 		Long value = getOptionalLong(index);
@@ -98,6 +143,17 @@ public final class BdfList extends ArrayList<Object> {
 		return value.intValue();
 	}
 
+	/**
+	 * Returns the integer at the specified index, or the given default value
+	 * if the object at the specified index is null.
+	 * <p>
+	 * This method should be used in preference to
+	 * <code>getLong(index, defaultValue).intValue()</code> as it checks for
+	 * overflow/underflow.
+	 *
+	 * @throws FormatException if the index is out of range, or if the value
+	 * at the specified index cannot be represented as a Java int.
+	 */
 	public Integer getInt(int index, Integer defaultValue)
 			throws FormatException {
 		Integer value = getOptionalInt(index);
diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java
index fe710becd..f134d2614 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java
@@ -1,70 +1,178 @@
 package org.briarproject.bramble.api.data;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.nullsafety.NotNullByDefault;
 
 import java.io.IOException;
 
+/**
+ * An interface for reading BDF objects from an input stream.
+ * <p>
+ * The readX() methods throw {@link FormatException} if the data is not in
+ * canonical form, but the hasX() and skipX() methods do not check for
+ * canonical form.
+ */
 @NotNullByDefault
 public interface BdfReader {
 
 	int DEFAULT_NESTED_LIMIT = 5;
 	int DEFAULT_MAX_BUFFER_SIZE = 64 * 1024;
 
+	/**
+	 * Returns true if the reader has reached the end of its input stream.
+	 */
 	boolean eof() throws IOException;
 
+	/**
+	 * Closes the reader's input stream.
+	 */
 	void close() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF null.
+	 */
 	boolean hasNull() throws IOException;
 
+	/**
+	 * Reads a BDF null from the input.
+	 */
 	void readNull() throws IOException;
 
+	/**
+	 * Skips over a BDF null.
+	 */
 	void skipNull() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF boolean.
+	 */
 	boolean hasBoolean() throws IOException;
 
+	/**
+	 * Reads a BDF boolean from the input and returns it.
+	 */
 	boolean readBoolean() throws IOException;
 
+	/**
+	 * Skips over a BDF boolean.
+	 */
 	void skipBoolean() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF integer, which
+	 * has the same range as a Java long.
+	 */
 	boolean hasLong() throws IOException;
 
+	/**
+	 * Reads a BDF integer from the input and returns it as a Java long.
+	 */
 	long readLong() throws IOException;
 
+	/**
+	 * Skips over a BDF integer.
+	 */
 	void skipLong() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF integer and the
+	 * value would fit within the range of a Java int.
+	 */
 	boolean hasInt() throws IOException;
 
+	/**
+	 * Reads a BDF integer from the input and returns it as a Java int.
+	 *
+	 * @throws FormatException if the value exceeds the range of a Java int.
+	 */
 	int readInt() throws IOException;
 
+	/**
+	 * Skips over a BDF integer.
+	 *
+	 * @throws FormatException if the value exceeds the range of a Java int.
+	 */
 	void skipInt() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF float, which has
+	 * the same range as a Java double.
+	 */
 	boolean hasDouble() throws IOException;
 
+	/**
+	 * Reads a BDF float from the input and returns it as a Java double.
+	 */
 	double readDouble() throws IOException;
 
+	/**
+	 * Skips over a BDF float.
+	 */
 	void skipDouble() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF string.
+	 */
 	boolean hasString() throws IOException;
 
+	/**
+	 * Reads a BDF string from the input.
+	 *
+	 * @throws IOException If the string is not valid UTF-8.
+	 */
 	String readString() throws IOException;
 
+	/**
+	 * Skips over a BDF string without checking whether it is valid UTF-8.
+	 */
 	void skipString() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF raw.
+	 */
 	boolean hasRaw() throws IOException;
 
+	/**
+	 * Reads a BDF raw from the input and returns it as a byte array.
+	 */
 	byte[] readRaw() throws IOException;
 
+	/**
+	 * Skips over a BDF raw.
+	 */
 	void skipRaw() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF list.
+	 */
 	boolean hasList() throws IOException;
 
+	/**
+	 * Reads a BDF list from the input and returns it. The list's contents
+	 * are parsed and validated.
+	 */
 	BdfList readList() throws IOException;
 
+	/**
+	 * Skips over a BDF list. The list's contents are parsed (to determine
+	 * their length) but not validated.
+	 */
 	void skipList() throws IOException;
 
+	/**
+	 * Returns true if the next object in the input is a BDF dictionary.
+	 */
 	boolean hasDictionary() throws IOException;
 
+	/**
+	 * Reads a BDF dictionary from the input and returns it. The dictionary's
+	 * contents are parsed and validated.
+	 */
 	BdfDictionary readDictionary() throws IOException;
 
+	/**
+	 * Skips over a BDF dictionary. The dictionary's contents are parsed
+	 * (to determine their length) but not validated.
+	 */
 	void skipDictionary() throws IOException;
 }
diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfWriter.java b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfWriter.java
index 1427859a6..63f3a4357 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfWriter.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfWriter.java
@@ -1,28 +1,74 @@
 package org.briarproject.bramble.api.data;
 
+import org.briarproject.bramble.api.FormatException;
+
 import java.io.IOException;
 import java.util.Collection;
 import java.util.Map;
 
+/**
+ * An interface for writing BDF objects to an output stream. The BDF output
+ * is in canonical form, ie integers and length fields are represented using
+ * the minimum number of bytes and dictionary keys are unique and sorted in
+ * lexicographic order.
+ */
 public interface BdfWriter {
 
+	/**
+	 * Flushes the writer's output stream.
+	 */
 	void flush() throws IOException;
 
+	/**
+	 * Closes the writer's output stream.
+	 */
 	void close() throws IOException;
 
+	/**
+	 * Writes a BDF null to the output stream.
+	 */
 	void writeNull() throws IOException;
 
+	/**
+	 * Writes a BDF boolean to the output stream.
+	 */
 	void writeBoolean(boolean b) throws IOException;
 
+	/**
+	 * Writes a BDF integer (which has the same range as a Java long) to the
+	 * output stream.
+	 */
 	void writeLong(long l) throws IOException;
 
+	/**
+	 * Writes a BDF float (which has the same range as a Java double) to the
+	 * output stream.
+	 */
 	void writeDouble(double d) throws IOException;
 
+	/**
+	 * Writes a BDF string (which uses UTF-8 encoding) to the output stream.
+	 */
 	void writeString(String s) throws IOException;
 
+	/**
+	 * Writes a BDF raw to the output stream.
+	 */
 	void writeRaw(byte[] b) throws IOException;
 
+	/**
+	 * Writes a BDF list to the output stream.
+	 *
+	 * @throws FormatException if the contents of the given collection cannot
+	 * be represented as (nested) BDF objects.
+	 */
 	void writeList(Collection<?> c) throws IOException;
 
+	/**
+	 * Writes a BDF dictionary to the output stream.
+	 *
+	 * @throws FormatException if the contents of the given map cannot be
+	 * represented as (nested) BDF objects.
+	 */
 	void writeDictionary(Map<?, ?> m) throws IOException;
 }