feat(contracts): index contract creations + /contracts/{recent,pioneers,stats}

[satyakwok]

Why

Phase 2 of consolidating the testnet explorer onto a single indexer (indexer-rs). After #60 (stats/whale parity), the only remaining gap was the contract leaderboards — indexer-rs had no contract data at all. This adds it, so indexer-rs can fully replace the legacy indexer.

Changes

• Migration 0004 — contracts table (address PK, first/last_seen_block, code_hash NULL, tx_count, created_tx_hash) + recent/pioneers indexes.
• Detection — a tx with to_addr IS NULL is a contract creation; the created address = keccak(rlp(sender, nonce))[12:] (alloy Address::create), lowercased. Wired into both block-writer paths (single + batch).
• History backfill — one-time, on boot, background; fills contracts from existing creation txs (no-op once populated, so cheap on every restart).
• Routes — /contracts/recent (newest), /contracts/pioneers (oldest), /contracts/stats (sortable, defaults newest). Shape {"contracts":[{rank,address,first_seen_block,last_seen_block,code_hash}]} — matches the frontend (res?.contracts ?? []; null code_hash renders "—").

code_hash stays NULL for now (UI handles it); an eth_getCode pass is a later enhancement.

Tests

• CREATE-address known vector + bad-input rejection (block_writer).
• Response shape (routes/contracts).
• Smoke: fixture contract + /contracts/{recent,pioneers,stats} asserts (incl null code_hash).

Note

cargo-deny red is pre-existing (RUSTSEC-2026-0173 proc-macro-error2, repo-wide, unrelated).

Summary by CodeRabbit

• New Features
  • New contract leaderboard endpoints: /contracts/recent, /contracts/pioneers, and /contracts/stats for contract ranking queries
  • Automatic contract-creation transaction detection and historical backfill for contract data
  • Performance improvements via indexes on contract creation timestamps

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

📝 Walkthrough

Walkthrough

This PR introduces contract leaderboards across the full stack. A new contracts database table tracks contract-creation transactions (identified by null recipient addresses), with first/last-seen block numbers and an optional code hash. Block-write logic now detects contract creations, derives their CREATE addresses from sender and nonce, and upserts records atomically. A one-time backfill populates historical contracts. Three REST endpoints (/recent, /pioneers, /stats) serve ranked leaderboards with cached responses. Smoke tests verify endpoint contracts and response serialization.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• Sentriscloud/indexer-rs#35: Modifies crates/sync/src/block_writer.rs batch write path (write_block_batch COPY backfill), directly related to the batch write transaction extension in this PR.
• Sentriscloud/indexer-rs#37: Refactors batch_write_blocks function in the same module, overlapping with the contract-creation upsert logic added in this PR's batch write layer.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The PR description lacks critical required sections from the template including Scope, Checks (build, test, format, slither, storage), Linked issue, and Deploy impact checkboxes.	Add the missing template sections with appropriate checkboxes, test results, and deployment impact assessment to enable proper review and merge gating.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main changes: adding contract creation indexing and three new API endpoints for contract leaderboards.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/contracts-indexing-phase2

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}