A decentralized bug-bounty platform. USDC-collateralised. Self-custodial escrow. Paid automatically on merge. Built for Arbitrum.
DevBounty lets a project owner put real money behind a bug report without trusting a middleman. A sponsor funds a bounty in USDC held by an on-chain escrow contract. A security researcher ("hunter") claims it, fixes the issue, and opens a pull request. When a maintainer merges that pull request, GitHub notifies the backend, which verifies the merge and releases the escrowed USDC to the hunter on-chain. Hunters build public reputation through profiles and a leaderboard.
The escrow is self-custodial: funds sit in BountyEscrow until released. The backend's key can
only release to a hunter - it can never divert or refund - so a compromised key cannot steal
funds. The blockchain is the source of truth for money; the database is the source of truth for
workflow, and may lag the chain but never contradict it.
This repository is the backend: the Express API, the chain indexer, and the escrow contract. The web frontend lives in a separate repository.
- Self-custodial escrow. USDC stays in
BountyEscrowuntil an authorizedrelease()pays the hunter. Access is split on-chain - the backend can release, only the maintainer can refund. - Automatic payout on merge. A GitHub merge webhook is HMAC-verified, then strictly authorized (merged into the default branch, in the bounty's repo, by the claiming hunter) before the on-chain release fires. A maintainer manual-release covers a missed webhook.
- Wallet identity. Sign-In-With-Ethereum (EIP-4361) login with full signature recovery and a one-time server-side nonce, plus GitHub account linking via OAuth with tokens encrypted at rest.
- Sybil-resistant claims. One GitHub identity per wallet, a per-wallet active-claim cap, and a re-claim cooldown - enforced atomically so the cap can never be exceeded.
- Single-owner payout. The
submitted → releasingtransition is atomic; only the one caller that performs it can pay, so a bounty can never be released twice. - Chain indexer. A single-instance (DB-leased) poller mirrors
BountyCreated/Released/Refundedinto MongoDB; reputation is recomputed from an append-only ledger, so a replayed event can never double-count. It reads the live tip from the primary RPC and can replay long gaps after downtime in seconds via a large-range backfill RPC (INDEXER_RPC_URL, e.g. Envio HyperRPC), never trusting that lagging index at the tip. - Hardened API. Strict CORS + Origin CSRF check, per-IP and per-wallet rate limits, pinned-HS256 JWT sessions, idempotency keys on writes, and structured logging with secret redaction.
- Free-tier hostable. The indexer can run as its own worker or co-host inside the API
(
RUN_INDEXER_IN_PROCESS) so the whole loop runs on a single free service.
What works today on testnet, and what stands between it and a live, real-money product.
| Capability | State | What it needs |
|---|---|---|
| Full bounty lifecycle (create → fund → claim → submit → pay) | Works on Arbitrum Sepolia | - |
| Automatic on-merge payout | Works (proven end-to-end on testnet) | - |
| Quality gates (typecheck · lint · 182 tests) | Green | - |
| Reachable on the internet | Live on Render | - |
| Handle real money | Test USDC only | Mainnet deploy + real USDC |
| Production key custody | Env key on testnet | KMS/HSM signer before mainnet |
| Security audit | None | External audit before real funds |
Live and source-verified on Arbitrum Sepolia (testnet):
| Contract | Address |
|---|---|
| BountyEscrow | 0x8B71467B545aEdC0F4fc2094c46efEe2CB47Da9F |
| USDC (mock) | 0x3FD372BF3AE46539e5F07D9Bc00c2E5dfA0F0E2e |
| Layer | Stack |
|---|---|
| API | Node.js 20-22 · Express · TypeScript (ESM) |
| Validation / logging | zod · pino |
| Auth | SIWE (EIP-4361) · JWT (HS256) · AES-256-GCM token encryption at rest |
| Chain access | viem (public + wallet clients) |
| Database | MongoDB (Mongoose) |
| Contracts | Solidity 0.8 · OpenZeppelin · Hardhat |
| Target chain | Arbitrum Sepolia (testnet) |
| Tests | Vitest · supertest · mongodb-memory-server |
An npm-workspaces monorepo: api/ (Express API + chain indexer, layered as routes over a
framework-free shared/ domain core) and contracts/ (the Hardhat escrow). The API owns the
on-chain payout; a single indexer reads chain events and syncs the database.
flowchart LR
subgraph Client
FE["Frontend (separate repo)<br/>Next.js · wagmi"]
W["Wallet<br/>SIWE"]
end
subgraph API["Backend API (Express · Render)"]
R["routes + middleware"]
S["settleMerge<br/>(single payout owner)"]
end
DB[("MongoDB")]
IX["Chain indexer<br/>(single instance, DB-leased)"]
AL["Alchemy<br/>RPC node (tip + writes)"]
HS["Backfill RPC<br/>(Envio HyperRPC)"]
ESC["Arbitrum Sepolia<br/>BountyEscrow (USDC)"]
GH["GitHub<br/>merge webhook"]
FE --> W
FE -- "HTTPS / JSON (cookie)" --> R
W -- "SIWE" --> R
GH -- "signed webhook" --> R
R --> DB
R --> S
S -- "release()" --> AL
AL --> ESC
ESC -- "events" --> AL
ESC -- "events" --> HS
AL -- "tip logs" --> IX
HS -- "deep backfill" --> IX
IX --> DB
classDef chain fill:#fef2f2,stroke:#d63044,color:#7f1d1d
classDef svc fill:#fffbeb,stroke:#d97706,color:#78350f
classDef store fill:#f4f3f8,stroke:#736b8a,color:#3d3656
class ESC,AL,HS chain
class R,S,IX svc
class DB store
sequenceDiagram
autonumber
participant Sp as Sponsor
participant Hu as Hunter
participant Mn as Maintainer
participant API
participant GH as GitHub
participant Ch as BountyEscrow
participant Ix as Indexer
Sp->>API: create bounty (pending_deposit)
Sp->>Ch: approve + create() - USDC escrowed
Ch-->>Ix: BountyCreated
Ix->>API: mark bounty open
Hu->>API: claim + submit pull request
Mn->>GH: merge the pull request
GH->>API: signed webhook (HMAC + strict auth)
API->>Ch: release(hunter) via Alchemy
Ch-->>Hu: USDC transferred
Ch-->>Ix: BountyReleased
Ix->>API: mark paid · update reputation + leaderboard
Requires Node.js 20-22, MongoDB, and an Arbitrum Sepolia RPC URL.
npm install
cp api/.env.example api/.env # fill in the values
npm -w @devbounty/api run dev # start the API in watch modeThe escrow contract and on-chain payout activate once ESCROW_ADDRESS and a signer key are set;
without them the contract-independent API runs on its own.
npm -w @devbounty/api run typecheck
npm -w @devbounty/api run lint
npm -w @devbounty/api run test# 182 tests (Vitest + supertest + in-memory Mongo)Contracts are tested separately with Hardhat (lifecycle, access control, reentrancy):
npm -w @devbounty/contracts run testMIT © 2026 ozpool