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Version: 0.15 (unstable)

Testnet mock bridge sandbox

The mock bridge sandbox is a local Bridge API for testing app integrations with a NEAR Intents 1Click-style flow. It exposes the public /v0/* integration surface while using Sepolia native ETH and public Miden testnet behind the scenes.

The sandbox repository is BrianSeong99/miden-testnet-bridge.

What it provides​

  • A local Bridge API shaped like a 1Click integration: /v0/tokens, /v0/quote, /v0/deposit/submit, and /v0/status.
  • Sepolia native ETH inbound deposits to public Miden testnet payouts.
  • Miden public BridgeOutV1 notes for outbound testnet releases to Sepolia.
  • Solver behavior inside the sandbox service so builders can test app flows without operating a separate solver.
  • Evidence output with Sepolia transaction hashes, Miden transaction IDs, and lifecycle statuses.

Prerequisites​

  • Docker with Compose v2.
  • Rust toolchain for running the live evidence helper.
  • curl, jq, and OpenSSL.
  • A Sepolia RPC endpoint.
  • Sepolia ETH on two test-only keys:
    • solver key, used by the bridge service for Sepolia release transactions;
    • test-user key, used by the live evidence runner to send deposits.

The default public Miden testnet RPC is https://rpc.testnet.miden.io. The example Sepolia RPC below uses Tenderly's public endpoint.

Start the Sepolia profile​

git clone https://github.com/BrianSeong99/miden-testnet-bridge.git
cd miden-testnet-bridge
cp .env.sepolia.example .env

Fill .env with testnet-only values:

EVM_RPC_URL=https://gateway.tenderly.co/public/sepolia
MASTER_MNEMONIC=<builder-controlled-test-mnemonic>
SOLVER_PRIVATE_KEY=<funded-sepolia-solver-private-key>
DEMO_EVM_FUNDED_PRIVATE_KEY=<funded-sepolia-test-user-private-key>
MIDEN_MASTER_SEED_HEX=<fresh-32-byte-hex-seed>

Generate a fresh Miden seed:

perl -0pi -e "s/MIDEN_MASTER_SEED_HEX=.*/MIDEN_MASTER_SEED_HEX=$(openssl rand -hex 32)/" .env

Start the sandbox:

make sepolia

Check readiness:

curl -s http://localhost:8080/healthz
curl -s http://localhost:8080/readyz | jq .

Monitor the sandbox​

Use bridgectl for local status and flow inspection:

./bin/bridgectl status
./bin/bridgectl tokens
./bin/bridgectl flows
./bin/bridgectl flow <correlation-id>
make sepolia-logs
make sepolia-reset

The /demo/* and /lab endpoints in the sandbox are local helpers. App integrations should use only the /v0/* endpoints described in the API reference.

Run live testnet evidence​

After both Sepolia keys are funded, run:

RUSTFLAGS='-C debug-assertions=no' cargo run --bin sepolia_e2e 2>&1 | tee sepolia-e2e-live.log

The evidence runner drives both directions:

  1. Sepolia native ETH deposit -> /v0/deposit/submit -> solver-signed public P2ID mint on Miden -> recipient claim.
  2. Miden public BridgeOutV1 note -> bridge consume on Miden -> Sepolia native ETH release.

The run prints SEPOLIA_E2E_EVIDENCE lines with correlation IDs, Sepolia transaction hashes, Miden transaction IDs, and final balance deltas.

Published evidence​

The sandbox repository includes a terminal walkthrough video and a published evidence page:

Use those artifacts as examples of what to capture when reporting bridge test results: command line, lifecycle statuses, Sepolia transaction hashes, Miden transaction IDs, and explorer links.