AquaChain Agent Gateway

HTTP gateway for AI agents that pay via x402 (USDC on Base Sepolia) and relay drone water measurements to citizen-science-registry on Osmosis (osmo-test-5).

Humans keep using Keplr + the Angular app. Agents use machine payments + this API.

Phase status

Phase	Scope
G0	Rust scaffold, measurement validation, 402 stub, API spec
G1 (current)	x402 facilitator verify/settle, CosmJS Osmosis relay, @x402/fetch sample client
G2	LocalDAO v2 executable proposals
G3	Agent verifier registry + UI polish

Quick start

cd aquachain/agent-gateway
cp .env.example .env
# Set RELAYER_MNEMONIC + X402_PAYTO_ADDRESS for full stack
make test
make run

Dev acceptance without x402 wallet:

# in .env
X402_DEV_BYPASS=true

curl -sS http://localhost:8081/v1/capabilities | jq .
curl -sS -X POST http://localhost:8081/v1/measurements \
  -H 'Content-Type: application/json' \
  -d @examples/drone-measurement-yamuna.json | jq .

x402 agent client

cd examples
npm install
GATEWAY_URL=http://localhost:8081 \
EVM_PRIVATE_KEY=0x… \
node drone-agent.mjs

Requires Base Sepolia USDC on the agent wallet. The client uses @x402/fetch to handle HTTP 402 automatically.

Configuration

See .env.example. Secrets stay local (relayer mnemonic, pay-to address).

Variable	Role
X402_PAYTO_ADDRESS	EVM address receiving USDC
X402_FACILITATOR_URL	x402 facilitator (default testnet)
CSR_CONTRACT_ADDRESS	Osmosis citizen-science-registry
RELAYER_MNEMONIC	Signs Osmosis submit_data

Osmosis relay uses scripts/relay-submit-data.mjs (CosmJS bundled under scripts/).

Production

Public URL: https://x402.interchouette.net (custom domain; TLS via hosting provider).

Custom domain (DNS)

Type	Name	Target
CNAME	x402	aquachain-agent-gateway.onrender.com

After the CNAME propagates, attach the hostname on the gateway web service and set:

AGENT_GATEWAY_PUBLIC_URL=https://x402.interchouette.net

Point the frontend prod env agentGatewayUrl at the same URL (no trailing slash). x402 resource URLs in 402 responses use this value; it must match the URL agents call.

Set secrets in the hosting dashboard (never commit):

• RELAYER_MNEMONIC - Osmosis relayer with test OSMO
• X402_PAYTO_ADDRESS - Base Sepolia EVM address for USDC

Health check: GET /health. Capabilities: GET /v1/capabilities.

API

Full spec: docs/api.md.

Related

• Aquachain-contracts
• Frontend