Nano Memo

A super-simple, off-chain storage for Nano memo lines (and possibly other metadata in the future). There are existing APIs for this, but it's so simple, I figured I'd whip up an open-source solution.

New memos are signed by the sender and verified by the api, and requests to get the memo are signed by the receiver and verified by the api.

Huge shout out to the wonderful JNano project, which took this project from a reasonable amount of work down to almost nothing.

Create a Memo

You create a memo by passing most of the block to the API. This is so you can create the memo concurrent with the block on the network (or even before you create the network block). Since the API is write-once, this guarantees that you own the memo for your block, as block IDs can't be known ahead of time

A request is authorized by signing the payload with your private key (the public key being the account property), using the exact signing method of Nano itself (ED25519 + Blake2b). This can be tricky to get right with command line tools, so for this example we are piping a file directly into Httpie, for which we computed the signature beforehand.

Body

{
    "account": "nano_1pu7p5n3ghq1i1p4rhmek41f5add1uh34xpb94nkbxe8g4a6x1p69emk8y1d",
    "block": "5855E3B99E1E1DE391B9E24A2E05010B604E1F26F4ABEC194F7A589B3C62F80C",
    "link": "nano_1jwc9njxqe4dhth8au79ifxij1x5k5hwmn6eoprat47yfoataxqjbgsjrery",
    "memo": "Thanks for the pizza!"
}

Request

cat body | http POST https://memo.pkulak.com/blocks \
    Authorization:"Signature 65CA7D8580D6278F36B20A9DCD97AE9DD8C846C3A72C9B0BAFB6396B59117F1F63EB103FAC11EA6CE17685A4A1F6ED7C60E21AAF083B08AC0D61C6603AD3780A"

Response

HTTP/1.1 200 OK

Retrieve a Memo

To get a memo, authorization is the same (in this case the public key is the link property), but you sign the HTTP path. You also need to send the account you're expecting to have received from, as a verification.

Request

http https://memo.pkulak.com/blocks/5855E3B99E1E1DE391B9E24A2E05010B604E1F26F4ABEC194F7A589B3C62F80C/memo \
    Authorization:"Signature A489C20E9B3D1CC38A0F26DB05583C873B826B40F522FDD986664FAC7B8DDAFF1E3410C487DEA4B38344F717AB6DB0C97C83C7022EC45A1BC7A22BD35D298F0A" \
    account==nano_1pu7p5n3ghq1i1p4rhmek41f5add1uh34xpb94nkbxe8g4a6x1p69emk8y1d

Response

HTTP/1.1 200 OK
Content-Length: 21
Content-Type: text/plain; charset=UTF-8

Thanks for the pizza!

Note: you can retrieve your own memo by omitting the account query parameter and signing the path with your private key.

^{Donations welcome!
nano_3ytxuddbpkspahrxn6s5o67bszuc3u3ye97xdmpgsg7p9ymw96yogacjsznp}

pkulak/nanomemo

Nano Memo

Create a Memo

Retrieve a Memo