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RosenBridge Metadata Schema#

This page outlines a canonical, human‑readable schema for intent metadata used by Rosen flows. The Rosen dApp/tooling constructs and validates metadata; this document helps integrators and power users understand typical fields and structure.

Notes: - Exact fields and encoding may evolve; rely on the Rosen UI/tooling for production transactions. - Metadata is recorded or bound to on‑Ergo event boxes and validated by Guards during verification. - For special chains like Monero (no reliable tx metadata), the metadata is bound to a spend proof message; see bringing-monero.md.

Common Concepts#

  • Direction:
    • ChainX ➜ Ergo: Lock native asset on source chain, mint rToken on Ergo.
    • Ergo ➜ ChainX: Burn rToken on Ergo (via Bank), release native asset on target chain.
  • Address formats:
    • toAddress uses the target chain’s native format (Ergo P2PK, EVM/Bech32/addr1… per chain, etc.).
  • Fees:
    • bridgeFee is the Rosen fee component.
    • networkFee covers chain‑level fees (e.g., miner/gas fees) where applicable.

ChainX ➜ Ergo (Lock → Mint)#

Purpose: - Convey the user’s target Ergo address and fee parameters for minting the representative rToken on Ergo.

Illustrative example: 

{
  "to": "ergo",
  "toAddress": "9hJTi4GHb9cbLovbxJsAJ9TtU42CDnuWJ8w8Q4CfA3kpExRrAFw",
  "asset": "BTC",
  "amount": "100000",            // minor units if applicable
  "bridgeFee": "12212682",
  "networkFee": "190000",
  "memo": "optional user note",
  "nonce": "optional-unique-tag"
}

Field notes: - to: constant indicating the target platform (“ergo”). - toAddress: Ergo destination for the minted rTokens. - asset/amount: asset identifier/symbol and quantity (format depends on source chain conventions). - bridgeFee/networkFee: values shown in the Rosen UI at submit time. - memo/nonce: optional, may be ignored by validators.

Ergo ➜ ChainX (Burn → Release)#

Purpose: - Convey the user's target ChainX address and fee parameters for releasing the native asset on ChainX after burning the rToken on Ergo.

Illustrative example: 

{
  "to": "chainx",                     // e.g., "bitcoin", "cardano", "ethereum", "bsc"
  "toAddress": "bc1q.... or 0x.... or addr1....",
  "asset": "rBTC",                    // burned representative token on Ergo
  "amount": "100000",
  "bridgeFee": "12212682",
  "networkFee": "190000",
  "memo": "optional user note",
  "nonce": "optional-unique-tag"
}

Field notes: - to: specifies the external target (e.g., “bitcoin”, “cardano”, “ethereum”, “bsc”). - toAddress: destination on the target chain (format must match chain). - asset: the rToken on Ergo corresponding to the native asset on ChainX.

Monero: Metadata Bound to Spend Proof#

Monero wallets do not reliably carry arbitrary tx metadata. For ChainX ➜ Ergo with XMR: - Users generate a spend proof with the metadata JSON as the message. - The proof and the plaintext JSON are published/recorded on Ergo (by the user or Rosen tooling). - Only the locker can create a valid proof for the exact message, protecting integrity.

Reference example (from bringing-monero.md): 

{
  "to": "ergo",
  "bridgeFee": "12212682",
  "networkFee": "190000",
  "toAddress": "9hJTi4GHb9cbLovbxJsAJ9TtU42CDnuWJ8w8Q4CfA3kpExRrAFw",
  "fromAddress": ["monero_pub_spend_key"]
}

Encoding & Validation#

  • Encoding:
    • JSON string carried by the chain’s available metadata channel, or bound via proofs (e.g., Monero).
    • On Ergo (Bank/event boxes), metadata fields are carried/linked on‑chain in a canonical format used by Rosen watchers/guards.
  • Validation:
    • Watchers/guards validate that metadata and observed source events match (amount, asset, destination, fees).
    • Guard signing occurs only after watcher consensus and independent verification.

Best Practices#

  • Construct metadata via the Rosen dApp/tooling to ensure correctness.
  • Use canonical formats for addresses and asset identifiers.
  • Avoid manual edits; mismatched fields can delay or invalidate events.
  • For EVM targets, verify token contracts via the official assets list before interacting:

See Also#