Polkadot Bulletin chain

The Bulletin chain is a parachain providing distributed data storage and retrieval infrastructure for the Polkadot ecosystem. It is run using Polkadot SDK’s polkadot-omni-node.

Runtime functionality

The Bulletin chain runtime functions to store transactions for a given period of time (currently set at 2 weeks) and provide proof of storage.

Core functionality

The main purpose of the Bulletin chain is to provide storage for the People Chain.

Storage

The core functionality of the bulletin chain is in the transaction-storage pallet, which indexes transactions and manages storage proofs for arbitrary data.

Data is added via the transactionStorage.store extrinsic, provided the storage of the data is authorized by root call. Authorization is granted either for a specific account via authorize_account or for data with a specific preimage via authorize_preimage. Once data is stored, it can be retrieved from IPFS with the Blake2B hash of the data.

PeopleChain integration

The PeopleChain root will call transactionStorage.authorize_preimage (over XCM) to prime Bulletin to expect data with that hash, after which a user account will submit the data via transactionStorage.store (over XCM).

Pallets

polkadot-bulletin-chain/pallets/transaction-storage

Stores arbitrary data on IPFS via the store extrinsic, provided that either the signer or the preimage of the data are pre-authorized. Stored data can be retrieved from IPFS or directly from the node via the transaction index or hash.

Fresh benchmarks

Run on the dedicated machine from the root directory:

python3 scripts/cmd/cmd.py bench --runtime bulletin-westend

To run all benchmarks:

python3 scripts/cmd/cmd.py bench

SDK & Documentation

📚 Bulletin SDK

Multi-language client SDKs for Polkadot Bulletin Chain with complete transaction submission, automatic chunking, and DAG-PB manifest generation.

• Rust SDK - no_std compatible, works in native apps and ink! smart contracts
• TypeScript SDK - Browser and Node.js compatible

Both SDKs provide:

• ✅ All 8 pallet operations (store, authorize, renew, refresh, remove expired)
• ✅ DAG-PB manifests (IPFS-compatible)
• ✅ Authorization management (account and preimage)
• ✅ Progress tracking via callbacks

The TypeScript SDK includes automatic chunking with built-in transaction submission. The Rust SDK provides transaction submission via TransactionClient and offline chunking via BulletinClient (prepare-only; users submit chunks via subxt).

Quick Start: See sdk/README.md

📖 Documentation

Complete SDK Book: docs/book

The Bulletin SDK Book contains comprehensive guides including:

• Concepts (authorization, chunking, DAG-PB manifests)
• Rust SDK guide (installation, API reference, no_std usage, examples)
• TypeScript SDK guide (installation, API reference, PAPI integration, examples)
• Best practices and troubleshooting

To view the documentation locally:

cd docs/book
mdbook serve --open

Examples (JavaScript-based)

The examples/ directory contains Node.js (PJS and/or PAPI) scripts demonstrating how to interact with the Bulletin chain. For detailed setup and usage instructions, see examples/README.md.

Troubleshooting

Build Bulletin Mac OS

Algorithm file not found error

If you encounter an error similar to:

warning: cxx@1.0.186: In file included from /Users/ndk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/cxx-1.0.186/src/cxx.cc:1:
warning: cxx@1.0.186: /Users/ndk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/cxx-1.0.186/src/../include/cxx.h:2:10: fatal error: 'algorithm' file not found
warning: cxx@1.0.186:     2 | #include <algorithm>
warning: cxx@1.0.186:       |          ^~~~~~~~~~~
warning: cxx@1.0.186: 1 error generated.
error: failed to run custom build command for `cxx v1.0.186`

This typically means your C++ standard library headers can’t be found by the compiler. This is a toolchain setup issue.

To fix:

• Run xcode-select --install.
• If it says “already installed”, reinstall them (sometimes they break after OS updates):

sudo rm -rf /Library/Developer/CommandLineTools
xcode-select --install

• Check the Active Developer Path: xcode-select -p. It should output one of: /Applications/Xcode.app/Contents/Developer, /Library/Developer/CommandLineTools
• If it’s empty or incorrect, set it manually: sudo xcode-select --switch /Library/Developer/CommandLineTools
• If none of the above helped, see the official Mac OS recommendations for polkadot-sdk

dyld: Library not loaded: @rpath/libclang.dylib

This means that your build script tried to use libclang (from LLVM) but couldn’t find it anywhere on your system or in the DYLD_LIBRARY_PATH.

To fix:brew install llvm and

export LIBCLANG_PATH="$(brew --prefix llvm)/lib"
export LD_LIBRARY_PATH="$LIBCLANG_PATH:$LD_LIBRARY_PATH"
export DYLD_LIBRARY_PATH="$LIBCLANG_PATH:$DYLD_LIBRARY_PATH"
export PATH="$(brew --prefix llvm)/bin:$PATH"

Now verify libclang.dylib exists:

• ls "$(brew --prefix llvm)/lib/libclang.dylib"

If that file exists all good, you can rebuild the project now:

cargo clean
cargo build --release