Integration Overview

Concero V2 is a message protocol where each message defines its own delivery and verification stack.

At a high level:

1. Source app creates a MessageRequest and pays message fee.
2. Router emits a packed message receipt.
3. Selected relayer delivers submission to destination router.
4. Destination router computes verifier checks.
5. Destination app authenticates/asserts message and runs app logic.

Mental model: two enforcement layers

Layer 1: protocol execution

Handled by router + selected modules:

• fee quote and collection,
• relayer authorization (relayerLib.validate),
• verifier check computation (validationChecks).

Layer 2: application acceptance

Handled by your destination client contract:

• accept calls only from trusted router,
• allow only trusted relayer libs,
• assert verifier checks according to your policy,
• execute app logic in _conceroReceive.

Source chain responsibilities

• Build MessageRequest with the right chain selector, relayer lib, and verifier libs.
• Encode destination execution data (receiver + gas limit) with MessageCodec.encodeEvmDstChainData.
• Call getMessageFee and pass returned value to conceroSend when paying native.

Destination chain responsibilities

• Configure ConceroClient/ConceroClientBase safely.
• Allowlist relayer and verifier modules you trust.
• Set verification policy (all required verifiers by default in ConceroClient).
• Decode and process payload in _conceroReceive.