smom-dbis-138/services/chain138-oracle

Chain 138 Python Oracle

Unified Python replacement for the Chain 138 oracle stack:

• Off-chain pricing (Frankfurter FX + CoinGecko + on-chain ETH/USD aggregator)
• MetaMask-compatible spot price API (drop-in for token-aggregation routes)
• PMM liquidity (8 canonical DODO pools via DODOPMMIntegration)
• On-chain oracle push (replaces scripts/update-oracle-price.sh)
• Keeper mesh (replaces scripts/reserve/keeper-service.js + pmm-mesh-6s-automation.sh)

Token coverage is driven by config/omnl-m2-token-registry.v1.json (all M2 symbols) plus config/chain138-pmm-pools.json (PMM pool tokens).

Install

cd services/chain138-oracle
python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate
pip install -r requirements.txt

Load repo root .env (RPC, CoinGecko, keeper/oracle keys).

Commands

Command	Replaces	Purpose
python -m chain138_oracle serve	token-aggregation price routes + oracle-publisher	HTTP API on port 3500 (override CHAIN138_ORACLE_PORT)
python -m chain138_oracle mesh	pmm-mesh-6s-automation.sh	6s oracle + keeper + PMM TVL loop
python -m chain138_oracle keeper	keeper-service.js	Keeper-only loop
python -m chain138_oracle refresh-fx	iso4217-fx-refresh.ts	Refresh FX/crypto reference rates
python -m chain138_oracle update-oracle	update-oracle-price.sh	Push ETH/USD to aggregator
python -m chain138_oracle liquidity	chain138-dodo-liquidity.ts	PMM pool TVL snapshot
python -m chain138_oracle validate	—	Fail if any registry token lacks USD price

API endpoints

Endpoint	Description
GET /health	Service + on-chain ETH/USD status
GET /api/v1/prices/metamask/v2/chains/138/spot-prices?tokenAddresses=0x…	MetaMask Codefi-compatible spot prices
GET /api/v1/oracle/tokens	All registry tokens with price + PMM liquidity USD
GET /api/v1/oracle/liquidity/pools	Canonical PMM pool reserves and TVL
GET /api/v1/oracle/reference-rates	Live FX/crypto cache + contract addresses

Settlement / token-aggregation integration

Point spot prices at the Python oracle; keep OMNL mint/transfer on token-aggregation:

CHAIN138_ORACLE_URL=http://127.0.0.1:3500
TOKEN_AGGREGATION_URL=http://127.0.0.1:3000

Settlement middleware reads CHAIN138_ORACLE_URL for live BTC/USD (resolveLiveBtcUsd).

Production cutover (one command)

On the Chain 138 / OMNL host (Linux, systemd):

chmod +x scripts/deployment/cutover-chain138-oracle-python.sh
sudo RESTART_SETTLEMENT=1 ./scripts/deployment/cutover-chain138-oracle-python.sh

Dry-run first:

./scripts/deployment/cutover-chain138-oracle-python.sh --dry-run

This script:

1. Stops legacy pmm-mesh-6s-automation.sh, keeper-service.js, and old systemd units
2. Installs Python venv + validates all 37 M2 tokens
3. Sets CHAIN138_ORACLE_URL in .env
4. Enables chain138-oracle-api.service + chain138-oracle-mesh.service
5. Smoke-tests cBTC spot price and restarts settlement-middleware

Smoke test only:

CHAIN138_ORACLE_URL=http://127.0.0.1:3500 node scripts/deployment/smoke-chain138-oracle-pricing.mjs

Docker Compose (includes chain138-oracle on port 3500):

docker compose -f docker-compose.omnl-production.yml up -d chain138-oracle settlement-middleware

Required environment

Variable	Purpose
RPC_URL_138	Chain 138 JSON-RPC
COINGECKO_API_KEY	FX/crypto refresh (optional but recommended)
PRIVATE_KEY / DEPLOYER_PRIVATE_KEY	On-chain aggregator transmitter
KEEPER_PRIVATE_KEY	PriceFeedKeeper.performUpkeep
PRICE_FEED_KEEPER_ADDRESS	Keeper contract (default in code)
AGGREGATOR_ADDRESS	ETH/USD aggregator
OMNL_REQUIRE_LIVE_BTC_PRICE=1	Block repo BTC fallback (production)

systemd example

[Unit]
Description=Chain 138 Python Oracle Mesh
After=network.target

[Service]
Type=simple
WorkingDirectory=/opt/smom-dbis-138/services/chain138-oracle
EnvironmentFile=/opt/smom-dbis-138/.env
ExecStart=/opt/smom-dbis-138/services/chain138-oracle/.venv/bin/python -m chain138_oracle mesh
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target


## Coverage validation

```bash
python -m chain138_oracle validate
# or
python scripts/validate_coverage.py

Exits 0 when every token in omnl-m2-token-registry.v1.json resolves a positive USD price.

Architecture

flowchart LR
  CG[CoinGecko] --> FX[fx_refresh.py]
  FF[Frankfurter] --> FX
  FX --> CACHE[reference_cache]
  AGG[On-chain Aggregator] --> ETH[onchain_eth.py]
  ETH --> CACHE
  CACHE --> CANON[canonical_price.py]
  CANON --> API[FastAPI api.py]
  CANON --> LIQ[liquidity.py]
  PMM[DODO PMM Integration] --> LIQ
  MESH[mesh.py] --> ORA[onchain_oracle.py]
  MESH --> KEEP[keeper.py]

See also: docs/integration/ORACLE_AND_KEEPER_CHAIN138.md