Urbit Jamboard

An EVM smart contract for posting global +jamed data.

Entries submitted to the contract contain:

  $:  author=@p
      agent=@tas
      action=@tas
      data=*         :: jammed data
  ==

The accounts submitting entries must own the ship in the author field.

You should only submit +jamed data. The maximum allowed size of +jamed data is 1kb.

To do so from javascript, make use of the nockjs repo to build nouns and jam them.

example:

const noun = nockjs.Atom.fromCord('babay im goin on chain!')
const jammed = nockjs.jam(noun).bytes()

const tx = await contract.submitEntry(
  aura.patp2dec('~migrev-dolseg'),       // author
  toBytes16('hawk'),                     // agent
  toBytes16('some-action-name'),         // action
  new Uint8Array(jammed)                 // data
);
const reciept = await tx.wait();

see scripts/write.js for more.

---

Reading from mars

the jamboard.hoon thread can be used in any desk which contains

• lib/ethereum.hoon
• lib/ethio.hoon
• lib/strandio.hoon

its input argument is:

+$  input
    $:  rpc-url=@t
        author-filter=(unit @p)
        agent-filter=(unit @tas)
        action-filter=(unit @tas)
        start-block=(unit @ud)  :: otherwise, earliest
        end-block=(unit @ud)    :: otherwise, latest
    ==

and its output is:

+$  output  (list entry)
+$  entry
  $:  block-number=@ud
      when=@da
      author=@p
      agent=@tas
      action=@tas
      data=*
  ==

---

Local setup

1. open a terminal to the root of this repo
2. npm install
3. create a .env file with this RPC URL

   • RPC_URL=http://127.0.0.1:8545
     

4. npx hardhat compile
5. npx hardhat node
   • starts local chain
   • copy one of the fake account private keys to the .env file

   • RPC_URL=http://127.0.0.1:8545
     PRIVATE_KEY=0x...
     

6. open a new terminal to the root of this repo
7. deploy the contract
   • node scripts/deploy.js
   • copy the contract address to .env

   • RPC_URL=http://127.0.0.1:8545
     PRIVATE_KEY=0x...
     CONTRACT_ADDRESS=0x...
     

8. submit some fake data
   • node scripts/write.js --author="~migrev" --agent="hawk" --action="post-url" --data="some string here"
9. use the reader thread to read from the contract
   • -jamboard 'http://localhost:8545' ~ ~ ~ ~ ~