The file dist/mmtf.js provides the MMTF module in UMD format to work in node.js and browsers. This library version supports v1.0 of the MMTF specification.


MMTF.fetch and MMTF.fetchReduced are helper functions to quickly load and decode PDB IDs in MMTF format.

// Fetch PDB ID 3PQR in MMTF format and print the decoded MMTF data (or an loading/decoding error)
    // onLoad callback
    function( mmtfData ){ console.log( mmtfData ) },
    // onError callback
    function( error ){ console.error( error ) }


MMTF.traverse is a helper function to loop over the structural data in the decoded MMTF data object.

// `bin` is an Uint8Array containing the MMTF MessagePack
var mmtfData = MMTF.decode( bin );

// create event callback functions
var eventCallbacks = {
    onModel: function( modelData ){ console.log( modelData ) },
    onChain: function( chainData ){ console.log( chainData ) },
    onGroup: function( groupData ){ console.log( groupData ) },
    onAtom: function( atomData ){ console.log( atomData ) },
    onBond: function( bondData ){ console.log( bondData ) }

// traverse the structure and listen to the events
MMTF.traverse( mmtfData, eventCallbacks );


The decoder is exposed as MMTF.decode which accepts an Uint8Array containing the MMTF MessagePack and returns the decoded MMTF data as an object. Note, when using MMTF.fetch or MMTF.fetchReduced, decoding is not necessary.

// bin is Uint8Array containing the mmtf msgpack
var mmtfData = MMTF.decode( bin );
console.log( mmtfData.numAtoms );