Mirror posts look like
https://mirror.xyz/0x58E3a8Bc8CBFC10AC2972Fb9d0cF359E21eae56b/ZIO--5ywx1z-aKs0KCQ2PeTNutVKune7zhA1D09R0q0
0x58E3a8Bc8CBFC10AC2972Fb9d0cF359E21eae56b
is the ETH address
ZIO--5ywx1z-aKs0KCQ2PeTNutVKune7zhA1D09R0q0
is the Original-Content-Digest, a unique id mirror uses to store posts on Arweave
The easiest way to retrieve the arweave transaction associated with a mirror post is to use arweave's graphql endpoint: https://arweave.net/graphql
So for the above query for Original-Content-Digest
query {
transactions(tags: {name: "Original-Content-Digest", values: "ZIO--5ywx1z-aKs0KCQ2PeTNutVKune7zhA1D09R0q0"}, first: 2) {
edges {
node {
id
tags {
name
value
}
}
}
}
}
You'll get the following response
{
"data": {
"transactions": {
"edges": [
{
"node": {
"id": "HpcUE9Jigd0pvyYmNF6DjTljUSqn6Vecuf1hs50pdxk",
"tags": [
{
"name": "Content-Type",
"value": "application/json"
},
{
"name": "App-Name",
"value": "MirrorXYZ"
},
{
"name": "Contributor",
"value": "0x58E3a8Bc8CBFC10AC2972Fb9d0cF359E21eae56b"
},
{
"name": "Content-Digest",
"value": "810DD5o2elU0gX_opGJS8kIANVvZJUIyHW31tV5lPyk"
},
{
"name": "Original-Content-Digest",
"value": "ZIO--5ywx1z-aKs0KCQ2PeTNutVKune7zhA1D09R0q0"
}
]
}
}
]
}
}
}
Pull out the transaction id: HpcUE9Jigd0pvyYmNF6DjTljUSqn6Vecuf1hs50pdxk
Arweave hosts on an endpoint to pull tx info: https://arweave.net/HpcUE9Jigd0pvyYmNF6DjTljUSqn6Vecuf1hs50pdxk