diff --git a/chatto/src/main/javascript/ts/src/singleton/Sprintf.ts b/chatto/src/main/javascript/ts/src/singleton/Sprintf.ts
index fed2126..2d86c87 100644
--- a/chatto/src/main/javascript/ts/src/singleton/Sprintf.ts
+++ b/chatto/src/main/javascript/ts/src/singleton/Sprintf.ts
@@ -1,4 +1,80 @@
// ///
+/**
+ * Returns a formatted string:
+ *
+ * string sprintf(string format, mixed arg1?, mixed arg2?, ...)
+ *
+ * ### Argument swapping
+ *
+ * You can also swap the arguments. That is, the order of the placeholders doesn't have to match the order of the arguments.
+ * You can do that by simply indicating in the format string which arguments the placeholders refer to:
+ *
+ * sprintf('%2$s %3$s a %1$s', 'cracker', 'Polly', 'wants')
+ *
+ * And, of course, you can repeat the placeholders without having to increase the number of arguments.
+ *
+ * ### Named arguments
+ *
+ * Format strings may contain replacement fields rather than positional placeholders. Instead of referring to a certain argument,
+ * you can now refer to a certain key within an object. Replacement fields are surrounded by rounded parentheses - `(` and `)` -
+ * and begin with a keyword that refers to a key:
+ *
+ * var user = {
+ * name: 'Dolly',
+ * }
+ * sprintf('Hello %(name)s', user) // Hello Dolly
+ *
+ * Keywords in replacement fields can be optionally followed by any number of keywords or indexes:
+ *
+ * var users = [
+ * {name: 'Dolly'},
+ * {name: 'Molly'},
+ * {name: 'Polly'},
+ * ]
+ * sprintf('Hello %(users[0].name)s, %(users[1].name)s and %(users[2].name)s', {users: users}) // Hello Dolly, Molly and Polly
+ *
+ * Note: mixing positional and named placeholders is not (yet) supported
+ *
+ * ### Computed values
+ *
+ * You can pass in a function as a dynamic value and it will be invoked (with no arguments) in order to compute the value on the fly.
+ *
+ * sprintf('Current date and time: %s', function() { return new Date().toString() })
+ *
+ * @param format: format string
+ * The placeholders in the format string are marked by `%` and are followed by one or more of these elements, in this order:
+ * * An optional number followed by a `$` sign that selects which argument index to use for the value. If not specified,
+ * arguments will be placed in the same order as the placeholders in the input string.
+ * * An optional `+` sign that forces to preceed the result with a plus or minus sign on numeric values. By default,
+ * only the `-` sign is used on negative numbers.
+ * * An optional padding specifier that says what character to use for padding (if specified). Possible values are
+ * `0` or any other character precedeed by a `'` (single quote). The default is to pad with *spaces*.
+ * * An optional `-` sign, that causes `sprintf` to left-align the result of this placeholder. The default is to right-align the result.
+ * * An optional number, that says how many characters the result should have. If the value to be returned is shorter
+ * than this number, the result will be padded. When used with the `j` (JSON) type specifier, the padding length
+ * specifies the tab size used for indentation.
+ * * An optional precision modifier, consisting of a `.` (dot) followed by a number, that says how many digits should be
+ * displayed for floating point numbers. When used with the `g` type specifier, it specifies the number of significant
+ * digits. When used on a string, it causes the result to be truncated.
+ * * A type specifier that can be any of:
+ * * `%` — yields a literal `%` character
+ * * `b` — yields an integer as a binary number
+ * * `c` — yields an integer as the character with that ASCII value
+ * * `d` or `i` — yields an integer as a signed decimal number
+ * * `e` — yields a float using scientific notation
+ * * `u` — yields an integer as an unsigned decimal number
+ * * `f` — yields a float as is; see notes on precision above
+ * * `g` — yields a float as is; see notes on precision above
+ * * `o` — yields an integer as an octal number
+ * * `s` — yields a string as is
+ * * `t` — yields `true` or `false`
+ * * `T` — yields the type of the argument1
+ * * `v` — yields the primitive value of the specified argument
+ * * `x` — yields an integer as a hexadecimal number (lower-case)
+ * * `X` — yields an integer as a hexadecimal number (upper-case)
+ * * `j` — yields a JavaScript object or array as a JSON encoded string
+ * @param args: the arguments for the format string
+ */
export function Sprintf(message: string, ...args: any[]): string {
// @ts-ignore
return sprintf(message, ...args);