A variety of contracts power the Synapse Interchain Network, contained in the contracts-core section on GitHub (generated docs available here). The core of the protocol consists of a few different components:
Origin - Interface for sending messages to other chains. Also serves as the source of truth for resolving disputes since the origin chain is the only place where fraud can be proven with absolute certainty.
Destination - Interface for executing messages sent on other chains. Also has an interface for submitting fraud reports from Guards.
Summit - Contains all states from the entire network, resolves disputes and allows agents to bond.
Gas Oracle - Used for cross-chain dynamic gas pricing.
Agent Manager - used to keep track of all the bonded agents and their statuses.
The contracts have been audited by both Zellic and Trail of bits + reviewed extensively internally. Synapse employs extremely intensive unit, fuzz, and integration tests for the contracts & has an extremely comprehensive foundry test suite. A full overview of the test suite can be found here.
In addition to automated testing & manual review, Slither, a static analysis tool is ran on each commit & suggestions are considered carefully prior to merge. Other tools, including snyk + sonarqube are also used to scan for malignant dependencies.
This section will be updated with reporting guidelines for security issues + bounty program once SIN is live. Community members & contributors are encouraged to review protocol critical changes on github.