Building blockchain primitives for Rust, TypeScript, Python, Go, Java, and WASM.
ChainFoundry is a monorepo of four foundational Rust libraries for building blockchain data infrastructure. Each module is an independent Cargo workspace with language bindings for TypeScript, Python, Go, and Java — use one, use all.
Note: this project was previously known as ChainKit; the repo was renamed on 2026-04-18. Package names on crates.io, npm (
@chainfoundry/*), PyPI (chainfoundry-*), and Maven (io.chainfoundry) are unchanged.
Every team building AI agents, DeFi analytics, or blockchain tools hits the same wall: fragmented RPC clients, chain-specific decoders, indexers that break on reorgs, and error messages that are just hex strings.
ChainFoundry solves this with one unified stack:
| Problem | Without ChainFoundry | With ChainFoundry |
|---|---|---|
| RPC calls fail silently | You find out hours later | Circuit breakers auto-failover in milliseconds |
| Event data is chain-specific | Different decoder per chain | One decoder, 50+ protocol schemas, 7 chains |
| Chain reorgs corrupt your data | Your AI agent acts on stale state | Reorg-safe indexing, always canonical |
| Error messages are hex soup | 0x08c379a0... | "Insufficient balance" |
| Module | Description | Status | Docs | Examples |
|---|---|---|---|---|
chaincodec |
Universal ABI decoder — EVM events, calls, EIP-712, proxy detection, 50+ schemas | ✅ v0.1.2 (crates.io + npm) | docs | examples |
chainerrors |
EVM + Solana error decoder — reverts, panics, custom errors, program failures | ✅ v0.1.0 (crates.io + npm) | README | — |
chainrpc |
Production RPC transport — 7 chains, circuit breaker, rate limiter, caching, pool, MEV, 5 provider profiles (Alchemy, Infura, QuickNode, Chainstack, public) | ✅ v0.2.2 (crates.io + npm + PyPI) | docs | 31 examples |
chainindex |
Reorg-safe blockchain indexer — 7 chains, pluggable storage (SQLite/Postgres/RocksDB) | ✅ v0.1.1 (crates.io + npm) | docs | 21 examples |
All 4 modules ship with native bindings:
| Language | chaincodec | chainerrors | chainrpc | chainindex |
|---|---|---|---|---|
| TypeScript (napi-rs) | ✅ | ✅ | ✅ | ✅ |
| Python (PyO3/maturin) | ✅ | ✅ | ✅ | ✅ |
| Go (cgo) | ✅ | ✅ | ✅ | ✅ |
| Java (JNI) | ✅ | ✅ | ✅ | ✅ |
| WASM (wasm-bindgen) | ✅ | — | — | — |
31 modules, 301 tests, composable middleware stack for 7 blockchain families.
| Chain Family | Transport | ChainClient | Method Safety | CU Costs | Known Endpoints |
|---|---|---|---|---|---|
| EVM (Ethereum, Polygon, Arbitrum, ...) | ✅ | ✅ | ✅ | ✅ | ✅ |
| Solana | ✅ | ✅ | ✅ | ✅ | ✅ |
| Cosmos (Cosmos Hub, Osmosis, ...) | ✅ | ✅ | ✅ | ✅ | ✅ |
| Substrate (Polkadot, Kusama) | ✅ | ✅ | ✅ | ✅ | ✅ |
| Bitcoin | ✅ | ✅ | ✅ | ✅ | ✅ |
| Aptos | ✅ | ✅ | — | ✅ | ✅ |
| Sui | ✅ | ✅ | ✅ | ✅ | ✅ |
DedupTransport → CacheTransport → BackpressureTransport → ProviderPool → HttpRpcClient
Every layer wraps Arc<dyn RpcTransport> and itself implements the trait. Stack what you need.
- Provider Pool — Multi-provider failover with 5 selection strategies (RoundRobin, Priority, Weighted, LatencyBased, Sticky)
- Tiered Cache — 4-tier response cache (Immutable 1h / SemiStable 5m / Volatile 2s / NeverCache) with reorg invalidation
- CU-Aware Rate Limiting — Token bucket that knows
eth_getLogs= 75 CU,eth_blockNumber= 10 CU - Circuit Breaker — Three-state (Closed/Open/HalfOpen), automatic failover when providers go down
- Request Dedup — N concurrent identical calls = 1 HTTP request, shared response
- Auto-Batching — Collects individual calls into JSON-RPC batch requests within a time window
- MEV Protection — Detects 12 MEV-susceptible selectors, routes to private relays
- Gas Estimation — EIP-1559 recommendations (Slow/Standard/Fast/Urgent)
- Tx Lifecycle — Send, track, poll receipt, detect stuck, nonce management
- Prometheus Metrics — Per-provider success/failure/latency export
use chainrpc_http::{HttpRpcClient, pool_from_urls};
use chainrpc_core::transport::RpcTransport;
// Single client with built-in retry + circuit breaker
let client = HttpRpcClient::default_for("https://eth-mainnet.g.alchemy.com/v2/KEY");
let block: String = client.call(1, "eth_blockNumber", vec![]).await?;
// Multi-provider failover
let pool = pool_from_urls(&["https://alchemy.com/...", "https://infura.io/..."])?;
let resp = pool.send(JsonRpcRequest::auto("eth_blockNumber", vec![])).await?;| Document | Description |
|---|---|
| README | Full feature list, quick start, crate structure |
| Architecture | System diagram, request flow, design principles |
| Modules | All 27 modules with public API signatures |
| API Reference | Quick-lookup tables for every type and function |
| Use Cases | 16 real-world patterns with complete Rust code |
| Implementation | Design decisions, concurrency, internals |
| Examples | 22 runnable examples organized by category |
50+ protocol schemas, 13 examples, decode/encode any EVM event, call, or EIP-712 message.
EVM log → EvmDecoder → DecodedEvent { fields: { from, to, value }, ... }
Calldata → EvmCallDecoder → DecodedCall { function_name, inputs: [...] }
ABI + args → EvmEncoder → 0xaabbccdd...
| Feature | Status |
|---|---|
| EVM event log decoding | ✅ |
| Function call decoding | ✅ |
| Constructor decoding | ✅ |
| ABI encoding (bidirectional) | ✅ |
| EIP-712 typed data | ✅ |
| Proxy detection (EIP-1967, EIP-1822, EIP-1167) | ✅ |
| Auto ABI fetch (Sourcify + Etherscan) | ✅ |
| CSDL schema format (YAML) | ✅ |
| 50+ bundled protocol schemas | ✅ |
| Parallel batch decode (Rayon) | ✅ |
Tokens: ERC-20, ERC-721, ERC-1155, ERC-4626, WETH DEX: Uniswap V2, Uniswap V3, Curve, Balancer V2, Pendle Lending: Aave V3, Compound V2, Compound V3, Morpho Blue, MakerDAO Staking/Restaking: Lido, EigenLayer Perpetuals: GMX V1 Oracles: Chainlink Price Feeds, Chainlink OCR2 NFT Marketplaces: OpenSea Seaport, Blur Bridges: Across Protocol, Stargate Governance: Compound Governor Bravo
use chaincodec_evm::EvmDecoder;
use chaincodec_registry::MemoryRegistry;
let registry = MemoryRegistry::new();
registry.load_directory("./schemas")?;
let decoder = EvmDecoder::new();
let event = decoder.decode_event(&raw_log, &schema)?;
println!("{}: {:?}", event.schema, event.fields);npm install @chainfoundry/chaincodec # TypeScript
pip install chaincodec # Python| Document | Description |
|---|---|
| Getting Started | Install, first decode, quickstarts in Rust / TypeScript / Python / CLI |
| Examples Walkthrough | All 13 runnable examples explained with expected output |
| CSDL Reference | Complete schema format — types, fingerprints, versioning |
| Architecture | Every crate explained — design decisions and internals |
| Use Cases | What to build — indexers, analytics, wallets, security, trading |
Decodes Solidity reverts, panics, and custom errors from raw bytes.
0x08c379a0... → Error(string): "Insufficient balance"
0x4e487b71... → Panic(uint256): arithmetic overflow (0x11)
0xe450d38c... → ERC20InsufficientBalance(address, uint256, uint256)
- Revert string decoding (
Error(string)) - Panic code decoding with human-readable descriptions
- Custom error decoding (ERC-20/721, OpenZeppelin, Ownable)
- Golden fixture test suite
Pluggable blockchain indexer with automatic reorg detection and recovery.
- IndexerBuilder API for configuring chains, handlers, storage
- ReorgDetector — 4-scenario detection (simple, deep, to-genesis, chain-switch)
- BlockTracker — Sliding window with gap detection
- Storage backends — Memory, SQLite (WAL mode), PostgreSQL (JSONB events)
- Checkpoint system — Resume from last confirmed block
chainfoundry/
├── chaincodec/ # ABI decoder — v0.1.2 published
│ ├── crates/ # 8 crates (core, evm, registry, batch, stream, ...)
│ ├── schemas/ # 50+ bundled CSDL schemas
│ ├── bindings/ # node, python, wasm, go, java
│ └── cli/
├── chainerrors/ # Error decoder
│ ├── crates/ # core, evm
│ └── bindings/ # node, python, go, java
├── chainrpc/ # RPC transport — 31 modules, 301 tests, 7 chains
│ ├── crates/ # core (31 modules), http, ws, providers
│ ├── bindings/ # node, python, go, java
│ ├── examples/ # 31 runnable examples
│ ├── docs/ # 5 documentation files
│ └── cli/
└── chainindex/ # Blockchain indexer — 397 tests, 7 chains
├── crates/ # core, evm, solana, cosmos, substrate, bitcoin, aptos, sui, storage
├── bindings/ # node, python, go, java
└── examples/ # 21 runnable examples
| Module | Metric |
|---|---|
| chaincodec | >1M events/sec single-thread, >5M with Rayon |
| chainrpc | ~1ns middleware overhead per layer (vs 5-100ms network) |
| chainindex | Reorg detection in O(window_size) |
# chaincodec — decode events, calls, encode, proxy detection
cargo install chaincodec-cli
chaincodec decode-log --topics 0xddf252ad... --data 0x000...
# chainrpc — test RPC calls, benchmark providers
cargo install chainrpc-cli
chainrpc call --url https://... --method eth_blockNumber
# chainerrors — decode error data
cargo install chainerrors-cli
chainerrors decode --data 0x08c379a0...The CI/CD pipeline, publishing workflow, build system, and module testing for ChainFoundry were developed with the assistance of Claude (Anthropic) — including crates.io publishing, npm/PyPI release automation, cross-platform Rust builds, and language binding generation. Anything wrong open for suggestions and improvement.
See CONTRIBUTING.md. Each module has independent CI:
cd chaincodec && cargo test --workspace
cd chainerrors && cargo test --workspace
cd chainrpc && cargo test --workspace
cd chainindex && cargo test --workspaceMIT — see LICENSE
Join the ChainFoundry Discord to ask questions, share what you're building, and contribute: discord.gg/mad7PMnbZP
Built by @darshan_aqua — questions, feedback, and contributions welcome. For community discussion, join us on Discord.
- v0.1 (done): chaincodec v0.1.2, chainrpc v0.1.1, chainindex v0.1.1 — published to crates.io + npm
- v0.2 (done): chainerrors-solana decoder, unified ChainClient trait, 5 new chain transports + indexers
- v0.2.2 (latest): chainrpc v0.2.2 — PyPI catch-up, Chainstack provider profile, README updates
- v1.0 (next): E2E integration tests with Anvil, publish chainerrors to crates.io / npm / PyPI
- v2.0: Cross-chain event correlation, WebSocket subscriptions, fuzz testing