diff --git a/index.html b/index.html
index d0059bc..7df253b 100644
--- a/index.html
+++ b/index.html
@@ -22,6 +22,9 @@
     <!-- still experimenting, see webdav.html -->
     <script src='dependencies/webdav.js'></script> 
 
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/cytoscape/3.8.2/cytoscape.min.js"></script>
+    <script src="https://cytoscape.org/cytoscape.js-euler/cytoscape-euler.js"></script>
+
     <!-- replacing with local copies as CDNs are like unpkg tend to be slow
     <script type="module" src="https://unpkg.com/immers-client/dist/destination.bundle.js"></script>
     <script src="https://aframe.io/releases/1.3.0/aframe.min.js"></script>
@@ -1965,6 +1968,121 @@ function rescalePlace(scale = 10, yoffset=-1){
 	} )
 }
 
+// from https://glitch.com/edit/#!/zen-pim?path=graph-cyto-headless.html
+// see also https://observablehq.com/@utopiah/d3-pim-graph
+// motivated by https://these.arthurperret.fr/chapitre-4.html#cosmographe-et-cosmoscope
+
+const cytoJson = "https://vatelier.benetou.fr/MyDemo/newtooling/wiki_graph_cyto.json"
+  
+var cy
+var jsonLoaded
+
+fetch(cytoJson)
+  .then(function (response) {
+    return response.json();
+  })
+  .then(function (json) {
+  // take nodes from wiki.Nodes then construct an array in elements for cytoscape format
+  // or directly from JSON http://js.cytoscape.org/#notation/elements-json
+    jsonLoaded = json
+    startCytoWithData(json)
+  })
+  .catch(function (err) {
+    console.log(err);
+});
+  
+// should instead directly use https://vatelier.net/MyDemo/newtooling/wiki_graph_cyto.json
+// generated from https://vatelier.net/MyDemo/newtooling/build_graph_cytograph.js
+// cf instead http://js.cytoscape.org/demos/tokyo-railways/tokyo-railways.json more detail
+// with details on how to load the JSON
+  
+function runCytoAnalysis(){
+  console.log('----------------- network analysis started --------------')  
+  if (!cy.nodes('[id = "Analysis.Analysis"]').length) {
+    console.warn('Wrong dataset, cancelling')
+    return
+  }
+  // example of queries
+  var aStar = cy.elements().aStar({ root: '[id = "Analysis.Analysis"]', goal: '[id = "Analysis.CostsAndBenefitsOfSocietalMembership"]' })
+  if ( aStar.path){
+    console.log("Path from Analysis.Analysis to Analysis.CostsAndBenefitsOfSocietalMembership", aStar.path.edges() , aStar.path.nodes() )
+    aStar.path.select()
+  }
+  console.log( cy.nodes('[id = "Analysis.Analysis"]').neighborhood() )
+  before = Date.now()
+  var bc = cy.elements().bc()
+  after = Date.now()
+  console.log("took ", after-before, "ms to run.")
+  console.log( 'bc of j: ' + bc.betweenness('[id = "Analysis.Analysis"]') )
+  console.log( cy.nodes('[id = "Analysis.CostsAndBenefitsOfSocietalMembership"]').neighborhood() )
+  //no need to run cy.elements().bc() again. It's done once for the whole graph.
+  console.log( 'bc of j: ' + bc.betweenness('[id = "Analysis.CostsAndBenefitsOfSocietalMembership"]') )
+  console.log('----------------- network analysis done -----------------')
+}
+  
+function startCytoWithData(json){
+  cy = cytoscape({
+    headless:true,
+    elements: json.elements
+  })
+  
+  //runCytoAnalysis() //quite demanding, skipped for now.
+  
+  let defaults = {
+    name: 'euler',
+    springLength: edge => 80,
+    springCoeff: edge => 0.0008,
+    mass: node => 4,
+    gravity: -1.2,
+    pull: 0.001,
+    theta: 0.666,
+    dragCoeff: 0.02,
+    movementThreshold: 1,
+    timeStep: 20,
+    refresh: 10,
+    animate: true,
+    animationDuration: undefined,
+    animationEasing: undefined,
+    maxIterations: 1000,
+    maxSimulationTime: 4000,
+    ungrabifyWhileSimulating: false,
+    fit: true,
+    padding: 30,
+    // Constrain layout bounds with one of
+    // - { x1, y1, x2, y2 }
+    // - { x1, y1, w, h }
+    // - undefined / null : Unconstrained
+    boundingBox: undefined,
+
+    // Layout event callbacks; equivalent to `layout.one('layoutready', callback)` for example
+    ready: function(){ console.log("graph ready", cy.json()) }, // on layoutready
+    stop: stableGraph(), // on layoutstop
+    randomize: false
+  };
+  
+  // disabled for tests
+  //cy.layout( defaults ).run(); // too demanding for the entire graph, should limit to a subset
+}
+  
+function stableGraph(){
+  var exportableJSON = cy.json()
+  console.log( 'exportable JSON', exportableJSON );
+  // not actually stable!
+  // still could be used as a form of caching BUT... would take into account new nodes added since
+  
+  var node = "ReadingNotes.ApocalypticAI"
+  if (!cy.nodes('[id = "'+node+'"]').length) {
+    console.warn('Wrong dataset, cancelling')
+    return
+  }
+  console.log('should add/update AFrame nodes e.g', cy.elements('[id = "'+node+'"]').position())
+  console.log('could add all the nodes then their links with proper attributes in order to do select() after')
+  // using e.g. cy.nodes().forEach( n => console.log(n.data(), n.position() ) )
+  // cy.edges().forEach( e => console.log(e.data(), e.sourceEndpoint(), e.targetEndpoint() ))
+  // warning, very costly!
+  // run on entire wiki though whereas previous D3 instance limited to 10 pages and their targets
+}
+
 // could change model opacity based on hand position, fading out when within a (very small here) safe space
 </script>
 <div id="observablehq-key">