Imported from zhoudongchao9-cloud/blueprint-repl (crates/chain-setup/anvil/snapshots/AGENTS.md). Install upstream with npx skills add zhoudongchao9-cloud/blueprint-repl --skill snapshots. Copyright stays with the author.

snapshots

Purpose

Stores Anvil chain snapshots for the local testnet, including the Forge broadcast output from contract deployment and the resulting chain state.

Contents (one hop)

Subdirectories

• (none)

Files

• localtestnet-broadcast.json - Forge broadcast transaction log from running LocalTestnet.s.sol, containing all CREATE transactions for contract deployments (e.g., MultiAssetDelegation) with their addresses, calldata, and chain configuration.
• localtestnet-state.json - Full Anvil state dump after running the local testnet deployment script, containing all accounts, balances, contract bytecode, and storage.

Key APIs

• localtestnet-state.json is loaded by snapshot.rs via default_snapshot_path() which resolves to this directory relative to CARGO_MANIFEST_DIR
• snapshot_state_json() reads the state file for use with start_empty_anvil_testnet()

Relationships

• Read by ../src/snapshot.rs to provide pre-seeded chain state for empty testnet starts
• The broadcast file documents which contracts were deployed and at which addresses
• Used by test harnesses across the workspace that need a fresh Anvil with deployed contracts

Provenance — keep in step with tnt-core-bindings

These fixtures deploy real tnt-core contracts, so their ABI must match the tnt-core-bindings version the workspace resolves. When the two drift, calls still succeed and decode into the wrong fields — e.g. tnt-core 0.19 reordered Types.JobCall (payment moved behind completed/isRFQ), so an 0.18 fixture read under 0.19.1 bindings reports every job as never completed. Regenerate the fixtures in the same change as any tnt-core-bindings bump.

• Current fixture: tnt-core 674403de (the merged G2 coordinate-order fix), matching tnt-core-bindings 0.19.1 plus the corrected aggregation bytecode.
• The broadcast's top-level commit field records the tnt-core commit it was generated from — check it first when a Tangle e2e test decodes nonsense.
• Regenerate by running script/sh/update-localtestnet-fixtures.sh in a tnt-core checkout and copying both files here. As of 674403de that script needs FOUNDRY_CODE_SIZE_LIMIT raised to ~1000000: LocalTestnetSetup's initcode is ~595 KB and forge caps initcode at twice the code-size limit.
• Deployment addresses are CREATE addresses derived from the deployer's nonce order, so they move whenever the deploy sequence changes. After regenerating, re-read them from the broadcast and update TANGLE_ADDRESS / RESTAKING_ADDRESS / STATUS_REGISTRY_ADDRESS in crates/testing-utils/anvil/src/tangle.rs plus the matching constants in cli/src/command/dev/up.rs.
• The snapshot is an anvil 1.7.x state dump; it must stay in step with ANVIL_TAG in ../src/anvil.rs because dump formats are not forward compatible.