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Woleet.io

Timestamp data

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Too busy to read the documentation?

You will find here very simple curl and shell code samples demonstrating the basic usage of the Woleet API.

To timestamp a file, you simply request the Woleet API to create a proof of timestamp of this file. You do this by creating a data anchor, which allows at the same time to create the proof, monitor the creation process and retrieve the proof receipt at the end.

But before, you need to compute the SHA256 hash of your file (its 'digital fingerprint').

Let's do it using a simple shell command using openssl to do the computation:

$ cat <your file> | openssl dgst -sha256 |  cut -d " " -f 2

e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

Now that you have the SHA256 hash of your file, you can create the data anchor by providing it to the anchor creation endpoint of the Woleet API.

Let's do it using a simple curl command to do a POST request:

curl --request POST \
  -u <email>:<password>
  --url https://api.woleet.io/v1/anchor \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --data '{"name":"My anchor","hash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"}'

{
  "id":"331674c8-0563-45f4-b363-e6cebc0625bb",
  "created":1556397050177,
  "lastModified":1556397050177,
  "name":"My anchor",
  "hash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "status":"WAIT"
}

Your data anchor is created!

Its identifier is in the id attribute of the JSON object returned in the body of the response.

Note the its status is WAIT, meaning that the data is waiting to be anchored in the bitcoin blockchain. The Woleet platform batches data anchoring requests, so you will have to wait a mean time of 3 hours to get your proof of timestamp.

You can probe your anchor status at any time with a simple GET request.
If you have a backend server, it is highly recommended to use our callback service to be informed in realtime:

curl --request GET \
  -u <email>:<password>
  --url https://api.woleet.io/v1/anchor/331674c8-0563-45f4-b363-e6cebc0625bb \
  --header 'accept: application/json'
  
{
  "id":"331674c8-0563-45f4-b363-e6cebc0625bb",
  "created":1556397050177,
  "lastModified":1556397050177,
  "name":"My anchor",
  "hash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "status":"CONFIRMED"
}

When the status is SENT (sent to the bitcoin blockchain) or CONFIRMED (confirmed 6 times by the bitcoin blockchain) you can (and really should) retrieve your proof of timestamp:

curl --request GET \
  --url https://api.woleet.io/v1/receipt/331674c8-0563-45f4-b363-e6cebc0625bb \
  --header 'accept: application/json'
  
{
  "targetHash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "merkleRoot":"ec4a21d9b4f4c60e34700012bfe0b3dacd46d928e9ff7cb12bbc1e8dc567093b",
  "proof":[{"left":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"},
  {"right":"164ea6ef8984a1be9a9064e40f58e1e99f82aa9ecff29bd1a07bee74965f7a49"},
  {"left":"19d54943a3ae4172fef2856f953d1eb988e7b512c9b9d06c53e225ae94c231c0"},
  {"right":"06f5f7540b35461cd1b9366a9e765c9165bd99c6679cb49d2c67bfae851c54cf"},
  {"left":"a3ce3262b6c61042fd7097c19b3af3acc72ceb63dcf53ef2017f184ec4740c78"},
  {"right":"4a15851b48ffdafe0212c7e489b1859cee3d7a53dde40393711ec957020f7b02"}],
  "anchors":[{"sourceId":"096e1f0f2406210db9b1ba0a1d08615ed8e4bebbdf444c541a21a028ed6829eb",
 "type":"BTCOpReturn"}],
  "type":"ChainpointSHA256v2",
  "@context":"https://w3id.org/chainpoint/v2"
}

You get your proof of timestamp. Keep it along the proven file: you need both to verify the proof.

You are all set!

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