CCIP Express

Express CCIP-Read handler.

Motivation

This lib was created with the purpose of making it easier to implement APIs that are fully compliant with the EIP-3668 specification. Its differential is that it is capable of handling middlewares per function by attaching any given number of endpoints to an Express router.

Usage

The supported request looks like the following:

# abi.encodeWithSelector(0x59d1d43c, 'com.twitter', '@blockful')
CALLDATA='0x59d1d43c194774734a8c16665005fd2c68cb7cc80b5aa6ffcb0c56ace654bc614902cf7f00000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000008626c6f636b66756c000000000000000000000000000000000000000000000000'

curl -X GET http://127.0.0.1/0x6AEBB4AdC056F3B01d225fE34c20b1FdC21323A2/$(CALLDATA)

curl -X POST http://127.0.0.1 -H "Content-Type: application/json" \
-d '{"sender": "0x6AEBB4AdC056F3B01d225fE34c20b1FdC21323A2", "calldata": $(CALLDATA)}'

Single handler with no middlewares

const handlers : FunctionHandler[] = [
  {
    signature: 'function text(bytes32 node, string key) view returns (string)',
    handlers: [
      (_: Request, res: Response, __: NextFunction) => {
        const { node, key } = res.locals
        res.json({ node, key })
      }
    ]
  }
]

app.use(CCIPHandler(handlers))

Multiple handlers with not middlewares

const handlers : FunctionHandler[] = [
  {
    signature: 'function text(bytes32 node, string key) view returns (string)',
    handlers: [
      (_: Request, res: Response, __: NextFunction) => {
        const { node, key } = res.locals
        res.json({ node, key })
      }
    ]
  },
  {
    signature: 'function setText(bytes32 node, string calldata key, string calldata value)',
    handlers: [
      (_: Request, res: Response, __: NextFunction) => {
        const { node, key } = res.locals
        res.json({ node, key })
      }
    ]
  }
]

app.use(CCIPHandler(handlers))

Single handler with middlewares

const handlers : FunctionHandler[] = [
  {
    signature: 'function text(bytes32 node, string key) view returns (string)',
    handlers: [
      (_: Request, res: Response, next: NextFunction) => {
        next()
      },
      (_: Request, res: Response, __: NextFunction) => {
        const { node, key } = res.locals
        res.json({ node, key })
      },
      (_: Request, res: Response, next: NextFunction) => {
        next()
      },
    ]
  }
]

app.use(CCIPHandler(handlers))