VaraCore: Agent Trust Infrastructure for Vara Network

Three composable services in one Sails program: price oracle, reputation scorer, and agent registry. Any Vara agent can call all three at the same address.

Mainnet v1 (Hub-registered): 0xe1f8f2999a352f217292c9ddd85211dcda23923daa1b95ecb21ff20bf4d8d078 Mainnet v3 (all critique fixes): 0x86aa46695971b906329f7cac9f60a1ef6847cf730a63b5fd06d87346b61e47cb Hub Catalog: agents.vara.network (search "VaraCore") Explorer: vara.subscan.io

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Demo

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What Is VaraCore?

VaraCore is a shared infrastructure program on Vara mainnet. It gives every agent on the network three things it needs to operate autonomously: current asset prices, a trust score for any counterparty, and a searchable registry of agents by capability.

Any Vara program can call VaraCore with a single SCALE-encoded message. No API keys, no authentication. One program ID, three services, permanently on-chain.

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Services

OracleService: Multi-asset price feed

Tracks VARA/USD, BTC/USD, ETH/USD, DOT/USD, and USDT/USD. Prices are u128 with 8 decimal places (1_00000000 = $1.00). Multiple independent sources are aggregated; outlier rejection and a TWAP ring buffer (8 observations) smooth manipulation attempts.

let payload = ("Oracle", "GetPrice", "BTC/USD").encode();
// Returns: Result<OracleData, String>
// OracleData { price: u128, confidence: u128, timestamp: u64,
//              asset: String, source_count: u32, status: FeedStatus }
// Human price: data.price as f64 / 1e8

ReputationService: On-chain trust scores

Any caller can record a success or failure for any agent. Scores (0–1000) are computed from success rate, interaction volume, and account age. Useful before accepting a counterparty or deciding how much collateral to require.

let payload = ("Reputation", "ScoreAgent", agent_actor_id).encode();
// Returns: Result<ReputationData, String>
// score >= 400 = minimum trust threshold (enforced by AgentConsumer companion)
// score >= 600 = recommended for standard operations

Registry (AgentRegistryService): Capability-aware agent discovery

Agents register with tags (e.g., "price-feed", "defi", "governance"). Other agents query by capability or service type, filtering for active agents only.

let payload = ("Registry", "DiscoverAgents", filter).encode();
// Returns: Vec<AgentListing>

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Features

• Single address, three services: one VARACORE_PID constant covers oracle, reputation, and registry
• Permissionless writes: any caller can submit price data or record interactions; manipulation resistance comes from aggregation, not access control
• Cross-program native: designed for Sails msg::send_bytes_for_reply calls from other programs
• SCALE-encoded interface: IDL in varacore/varacore.idl; fully language-agnostic
• Permanent on-chain state: programs on Vara are immutable; VaraCore runs indefinitely
• Off-chain agent: TypeScript price-feeder pulls CoinGecko/Binance/Gate.io, aggregates, and calls UpdatePrice every 5 minutes. ScheduleRefresh proves autonomous on-chain self-messaging as a separate capability

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Tech Stack

Layer	Technology
On-chain program	Rust + Sails 0.10.4 (WASM)
Network	Vara Network (Gear Protocol)
Encoding	SCALE (parity-scale-codec 3.x)
Off-chain agent	TypeScript + @gear-js/api 0.44
Price sources	CoinGecko, Binance, Gate.io
Deploy tool	Vara Wallet CLI / gear-js API

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Integration (5 minutes)

Add to Cargo.toml:

parity-scale-codec = { version = "3", default-features = false, features = ["derive"] }
gstd = { git = "https://github.com/gear-tech/gear", features = ["async"] }

use gstd::msg;
use parity_scale_codec::Encode;

const VARACORE: ActorId = ActorId::new(hex_literal::hex!(
    "e1f8f2999a352f217292c9ddd85211dcda23923daa1b95ecb21ff20bf4d8d078"
));

// Query a price
let payload = ("Oracle", "GetPrice", "BTC/USD").encode();
let reply = msg::send_bytes_for_reply(VARACORE, &payload, 0, 50_000_000_000)
    .expect("send failed").await.expect("reply failed");
// reply prefix: 16 bytes (SCALE("Oracle")=7 + SCALE("GetPrice")=9).
// reply[16] = Result discriminant (0x00=Ok, 0x01=Err).
// Idiomatic: Result<OracleData,String>::decode(&mut &reply[16..])
// Manual: OracleData::decode(&mut &reply[17..]) after checking reply[16]==0x00

// Check agent reputation
let payload = ("Reputation", "ScoreAgent", counterparty).encode();

// Discover agents by capability
let payload = ("Registry", "GetAgentsByCapability", "price-feed").encode();

See varacore/SKILL.md for complete method signatures, response types, gas estimates, and decoding examples.

SCALE payload format: (service_route, method_name, ...args).encode()

Service	Route	Gas (query)	Gas (write)
OracleService	"Oracle"	500_000_000	2_000_000_000
ReputationService	"Reputation"	500_000_000	1_000_000_000
Registry (AgentRegistryService)	"Registry"	500_000_000	1_000_000_000

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Companion Programs (Live Cross-Program Calls)

Two demo programs deployed on Vara mainnet call VaraCore directly, proving the integration works:

Program	Address	Calls
PriceConsumer v3	0x0a7f8a61...	Oracle.GetPrice
AgentConsumer v3	0xa7821734...	Reputation.ScoreAgent + Registry.DiscoverAgents

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How It Works

Off-chain price-feeder agent (TypeScript)
  |
  +---> CoinGecko / Binance / Gate.io (3 sources)
  |     Outlier rejection → median aggregation
  |
  +---> Oracle.UpdatePrice (SCALE call, every ~100 blocks)
  |     ScheduleRefresh loop keeps prices fresh
  |
  +---> VaraCore WASM program (Vara mainnet)
          |
          +---> OracleService (TWAP + FeedStatus)
          +---> ReputationService (interaction log + score)
          +---> Registry/AgentRegistryService (capability index)
                       |
                       v
          Any Vara agent calls any service
          via msg::send_bytes_for_reply

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Running Locally

# Build the WASM program
cargo build --release --target wasm32-unknown-unknown

# Run tests
cargo test -p varacore -p price-consumer -p agent-consumer  # 75 tests

# Run the off-chain price agent
cd agent
cp .env.example .env    # fill in VARA_ENDPOINT, VARACORE_PROGRAM_ID, mnemonic
npm install
npm run price-agent

Required environment variables (agent/.env)

VARA_ENDPOINT=wss://rpc.vara.network
VARACORE_PROGRAM_ID=0xe1f8f2999a352f217292c9ddd85211dcda23923daa1b95ecb21ff20bf4d8d078
PRICE_AGENT_MNEMONIC=...     # funded Vara account
PRICE_CONSUMER_ID=0x...      # companion program address
AGENT_CONSUMER_ID=0x...      # companion program address

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Project Structure

varacore/
  src/
    oracle.rs       # OracleService — price feed, TWAP, FeedStatus
    reputation.rs   # ReputationService — interaction log, composite score
    registry.rs     # Registry (AgentRegistryService) — capability index, discovery
    lib.rs          # Program entry + service wiring
  varacore.idl      # Canonical SCALE interface (IDL)
  SKILL.md          # Hub Catalog skill document (integration reference)
price-consumer/     # Demo companion: calls OracleService
agent-consumer/     # Demo companion: calls Reputation + Registry
agent/
  src/
    price-agent.ts          # Continuous price update loop
    register-hub.ts         # Hub Catalog registration
    register-test-agents.ts # Pre-register demo agents
    seed-interactions.ts    # Pre-seed reputation data
  .env.example
submission/
  proof.md          # On-chain transaction proof

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License

MIT