Latest version now handles mentions and hashtags (LIMITATION if you use one - then you need to use both)
Note I used Blockly as my function node but it wouldn't upload to the forum as it exceed 32000 char limit so I've copied the JS it generates into a function node for here
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\"{{flow.did}}\",\"collection\": \"app.bsky.feed.post\", \"record\": { \"$type\": \"app.bsky.feed.post\",\"text\": \"{{text}}\",\"createdAt\": \"{{myymd}}T{{mytimes}}.{{mymillis}}Z\"\n\n{{{facets}}}\n\n } }","output":"str","x":850,"y":720,"wires":[["931227442ccb14dd","e53f5f7745109a5a"]]},{"id":"027f19aca8f3549f","type":"simpletime","z":"dd99f8450c6d098a","name":"","mydate":false,"myymd":true,"myyear":false,"mymonth":false,"mymonthn":false,"mydom":false,"mydoy":false,"myday":false,"myhourpm":false,"myhour":false,"mytime":false,"mytimes":true,"myminute":false,"myminutes":false,"mysecond":false,"mymillis":true,"myepoch":false,"myrawdate":false,"mypm":false,"x":680,"y":720,"wires":[["9d0922b21146d9e5"]]},{"id":"3c32c66dcd937c19","type":"change","z":"dd99f8450c6d098a","name":"","rules":[{"t":"set","p":"did","pt":"flow","to":"payload.did","tot":"msg","dc":true},{"t":"set","p":"accessJwt","pt":"flow","to":"payload.accessJwt","tot":"msg","dc":true}],"action":"","property":"","from":"","to":"","reg":false,"x":890,"y":670,"wires":[["9d215bf0bde7d990","70f22979df50dff3"]]},{"id":"70f22979df50dff3","type":"change","z":"dd99f8450c6d098a","name":"","rules":[{"t":"delete","p":"headers","pt":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":470,"y":720,"wires":[["027f19aca8f3549f"]]},{"id":"3ebcd3d1c1454446","type":"template","z":"dd99f8450c6d098a","name":"","field":"headers","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"{ \"Authorization\":\"Bearer {{flow.accessJwt}}\" }","output":"str","x":470,"y":770,"wires":[["e3543264d4471753"]]},{"id":"e3543264d4471753","type":"json","z":"dd99f8450c6d098a","name":"","property":"headers","action":"obj","pretty":false,"x":620,"y":770,"wires":[["62a77df00a14da2a","bb3f01506e35f79e"]]},{"id":"1a9817da605c639e","type":"template","z":"dd99f8450c6d098a","name":"","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"{\"identifier\":\"{{name}}\",\"password\":\"{{appPassword}}\"}","output":"str","x":440,"y":630,"wires":[["f0ea247730c98478"]]},{"id":"c2cb04d260412407","type":"debug","z":"dd99f8450c6d098a","name":"debug 467","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1180,"y":630,"wires":[]},{"id":"9d215bf0bde7d990","type":"debug","z":"dd99f8450c6d098a","name":"debug 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request","z":"dd99f8450c6d098a","name":"","method":"GET","ret":"obj","paytoqs":"ignore","url":"","tls":"","persist":false,"proxy":"","insecureHTTPParser":false,"authType":"","senderr":false,"headers":[],"x":630,"y":500,"wires":[["340d28fba5b3725a","be81b2a0b4047cd1"]]},{"id":"340d28fba5b3725a","type":"change","z":"dd99f8450c6d098a","name":"","rules":[{"t":"set","p":"mentionDid","pt":"flow","to":"payload.did","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":830,"y":540,"wires":[["56b8cfc4cfcdeb84","66d96ecb386154c2"]]},{"id":"56b8cfc4cfcdeb84","type":"template","z":"dd99f8450c6d098a","name":"","field":"facets","fieldType":"msg","format":"handlebars","syntax":"mustache","template":",\n\"facets\": [\n{\n \"index\": {\n \"byteStart\": {{mentionStart}},\n \"byteEnd\": {{mentionEnd}}\n },\n \"features\": [\n {\n \"$type\": \"app.bsky.richtext.facet#mention\",\n \"did\": \"{{flow.mentionDid}}\"\n }\n ]\n},\n {\n \"index\": {\n \"byteStart\": {{hashtagStart}},\n \"byteEnd\": {{hashtagEnd}}\n },\n \"features\": [\n {\n \"$type\": \"app.bsky.richtext.facet#tag\",\n \"tag\": \"{{hashtag}}\"\n }\n ]\n }\n ]","output":"str","x":660,"y":580,"wires":[["b2bd616a8f37767c"]]},{"id":"b2bd616a8f37767c","type":"change","z":"dd99f8450c6d098a","name":"","rules":[{"t":"delete","p":"url","pt":"msg"},{"t":"delete","p":"headers","pt":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":820,"y":580,"wires":[["22f90199bd33d7ad","1a9817da605c639e"]]},{"id":"5dcdb13abc220f42","type":"inject","z":"dd99f8450c6d098a","name":"plain","props":[{"p":"text","v":"This is test post using NodeRED","vt":"str"},{"p":"name","v":"xxxxx.bsky.social","vt":"str"},{"p":"appPassword","v":"xxxxxx","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":140,"y":560,"wires":[["8b34ec1fff3ecef6"]]},{"id":"66d96ecb386154c2","type":"debug","z":"dd99f8450c6d098a","name":"debug 470","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1180,"y":540,"wires":[]},{"id":"be81b2a0b4047cd1","type":"debug","z":"dd99f8450c6d098a","name":"debug 471","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"payload","statusType":"auto","x":1180,"y":500,"wires":[]},{"id":"2c73ebab576739d5","type":"comment","z":"dd99f8450c6d098a","name":"Requires simpletime node","info":"","x":570,"y":460,"wires":[]},{"id":"a017dc0cd32db1dd","type":"function","z":"dd99f8450c6d098a","name":"Blocky generated JS","func":"var msgText, mentionStart, hashtagStart, mentionEnd, hashtagEnd, hashtag, facets;\n\n\nmsgText = String(msg['text']) + ' ';\nmentionStart = msgText.indexOf('@') + 1;\nhashtagStart = msgText.indexOf('#') + 1;\nif (mentionStart > 0) {\n mentionEnd = msgText.slice((mentionStart - 1), msgText.length).indexOf(' ') + 1;\n msg['url'] = ('https://bsky.social/xrpc/com.atproto.identity.resolveHandle?handle=' + String(msgText.slice(((mentionStart + 1) - 1), mentionEnd - 1)));\n}\nif (hashtagStart > 0) {\n hashtagEnd = msgText.slice((hashtagStart - 1), msgText.length).indexOf(' ') + 1;\n hashtagEnd = hashtagStart + (hashtagEnd - 1);\n hashtag = msgText.slice(((hashtagStart + 1) - 1), hashtagEnd - 1);\n msg['hashtag'] = hashtag;\n node.status({fill:\"blue\", shape:\"ring\", text:hashtag});\n}\nmsg['mentionStart'] = (mentionStart - 1);\nmsg['mentionEnd'] = (mentionStart + (mentionEnd - 2));\nmsg['hashtagStart'] = (hashtagStart - 1);\nmsg['hashtagEnd'] = (hashtagEnd - 1);\nfacets = '';\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":380,"y":500,"wires":[["8c3aec09fc23ed15"]]},{"id":"8b34ec1fff3ecef6","type":"junction","z":"dd99f8450c6d098a","x":250,"y":540,"wires":[["a017dc0cd32db1dd"]]},{"id":"45929b74029dac0a","type":"junction","z":"dd99f8450c6d098a","x":310,"y":590,"wires":[["1a9817da605c639e"]]}]
Note: the position of mentions and hashtags within a skeet have to be added on to the posted message as something called facets otherwise they just end up as plain text.
Further more, you have to look up something called the did which is BlueSky's internal id of a handle but at least that is easy to do
e.g simple get request that doesn't need authorisation
https://bsky.social/xrpc/com.atproto.identity.resolveHandle?handle=cymplecy.bsky.social
