Summary

Remove the github.com/celestiaorg/go-fraud dependency from celestia-node as fraud proofs are no longer working post-shwap and there are no plans to add them back. This will reduce maintenance burden and allow archiving the go-fraud repository.

Background

Discussion from Slack: Fraud proofs are not functional post-shwap, and there are no plans to reintroduce them. The go-fraud repository has accumulated recent PRs that require maintenance but provide no value since the functionality is unused.

Scope of Removal

Dependencies

• Remove github.com/celestiaorg/go-fraud v0.2.3 from go.mod (line 14)

Packages to Remove

• nodebuilder/fraud/ - entire package including:
  • module.go - fx module construction
  • fraud.go - interface definitions
  • constructors.go - service constructors
  • lifecycle.go - ServiceBreaker (granular service termination on fraud)
  • unmarshaler.go - proof unmarshaling
  • mocks/api.go - generated mocks

Files Requiring Modification

• go.mod / go.sum - remove dependency
• nodebuilder/module.go - remove fraud module registration
• nodebuilder/node.go - remove fraud-related code
• nodebuilder/settings.go - remove fraud imports/usage
• nodebuilder/default_services.go - remove fraud service
• nodebuilder/das/constructors.go - remove fraud/ServiceBreaker wrapping
• nodebuilder/p2p/pubsub.go - remove fraud pubsub setup
• nodebuilder/rpc/constructors.go - remove fraud RPC handlers
• das/daser.go - remove fraud proof handling
• share/eds/byzantine/bad_encoding.go - remove BEFP (BadEncodingFraudProof) implementation
• api/docgen/examples.go - remove fraud examples

Tests to Remove

• nodebuilder/tests/fraud_test.go - fraud integration tests
• das/daser_test.go - fraud-related test code

Notes

• The ServiceBreaker (in nodebuilder/fraud/lifecycle.go) was responsible for stopping services when fraud proofs were detected. Since fraud proofs won't be part of the protocol going forward, this can be removed entirely rather than replaced.
• This is a straight-forward removal of dead code, not a replacement with alternative functionality.

Related

Once this is complete, the [go-fraud repository](https://github.com/celestiaorg/go-fraud) can be archived.

Slack thread: https://celestia-team.slack.com/archives/C05CYC8EHBM/p1775836720278889?thread_ts=1775829066.847419&cid=C05CYC8EHBM

Would you like me to help with anything else, such as actually implementing this removal?