OmsWallet C SDK

Support Matrix

• macOS: supported for development and local testing, uses Keychain-backed secure storage
• Linux: supported runtime target for normal POSIX + libcurl environments, uses POSIX file-backed secure storage
• HTTP transport: libcurl only
• Session model: single-session and not thread-safe

Setup

Install dependencies

arch -arm64 brew install cmake pkg-config
brew install secp256k1 cjson curl

On Linux, install the equivalent development packages for cmake, pkg-config, libcurl, libcjson, and libsecp256k1.

Debian / Ubuntu example:

apt-get update
apt-get install -y build-essential cmake pkg-config libcurl4-openssl-dev libcjson-dev libsecp256k1-dev

Initialize the build directory

cmake -S . -B build
cmake --build build

Optional targets:

cmake -S . -B build -DOMS_WALLET_BUILD_DEMO=OFF -DOMS_WALLET_BUILD_CLI=OFF

OMS_WALLET_BUILD_DEMO and OMS_WALLET_BUILD_CLI only control those runtime binaries. They do not disable the library or the test targets.

Initialization

Call oms_wallet_config_init(...) before using wallet, indexer, or API helpers. The SDK no longer falls back to built-in runtime URLs when config is unset.

Minimal setup:

#include <wallet/oms_wallet_config.h>

if (oms_wallet_config_init("YOUR_ACCESS_KEY") != 0) {
    /* handle config initialization failure */
}

Common overrides:

oms_wallet_config_set_indexer_url_template("https://dev-{value}-indexer.sequence.app/rpc/Indexer/");
oms_wallet_config_set_api_rpc_url("https://dev-api.sequence.app/rpc/API");
oms_wallet_config_set_wallet_rpc_url("https://your-wallet-host/rpc/Wallet");
oms_wallet_config_set_origin_header("Origin: http://localhost:3000");
oms_wallet_config_set_storage_dir("/var/lib/oms-wallet-c-sdk");

The default wallet auth scope is proj_1. Only override it if your environment requires a different scope.

Call oms_wallet_config_cleanup() when you are done with SDK-owned config state.

oms_wallet_restore_session() returns:

• 1 when a usable saved session was restored
• 0 when no usable saved session exists yet
• -1 on an actual storage or restore failure

Linux Secure Storage

On Linux, secure storage uses a file-per-key backend with:

• directory permissions: 0700
• file permissions: 0600
• atomic replace on write

This Linux backend is permission-protected filesystem storage. It is not encrypted at rest like macOS Keychain storage.

Default storage path:

• $HOME/.oms-wallet-c-sdk when HOME is set
• ./.oms-wallet-c-sdk otherwise

Override the storage location with:

oms_wallet_config_set_storage_dir("/path/to/app-state");

Persisted keys used by the SDK:

• access-key: CLI-stored access key used to initialize SDK config
• seckey: signer private key for the current session
• challenge: pending email sign-in challenge
• verifier: pending email sign-in verifier
• oms_wallet_id: selected wallet id for follow-up wallet operations
• oms_wallet_address: last selected wallet address

Run tests

ctest --test-dir build --output-on-failure

# Focused request-signing parity test
./build/oms_wallet_request_signing_test

Current test coverage:

• oms_wallet_request_signing_test: validates canonical request payloads, preimages, digests, signatures, and authorization headers against checked-in vectors
• timestamps_test: validates nonce monotonicity from timestamp_next_nonce()
• secure_storage_test: Linux-only regression test for the POSIX secure-storage backend

Run the demo or cli

./build/oms-wallet-demo

# Init
./build/oms-wallet init --access-key AQAAAAAAAAK2JvvZhWqZ51riasWBftkrVXE

# Get token balances
./build/oms-wallet get-token-balances --chain-id 137 --contract-address 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 --wallet-address 0x8e3E38fe7367dd3b52D1e281E4e8400447C8d8B9 --include-metadata

# Sign in with Email
./build/oms-wallet sign-in-with-email --email andygruening@gmail.com

# Confirm Email sign in and automatically select the first matching wallet,
# or create one if none exists for that type
./build/oms-wallet confirm-email-sign-in --code 123456 --wallet-type ethereum

# Or, omit --wallet-type to list the available wallets returned by CompleteAuth
./build/oms-wallet confirm-email-sign-in --code 123456

# Optional: switch to a specific wallet later
./build/oms-wallet use-wallet --wallet-id <wallet-id>

# Optional: create an additional wallet of the default type (ethereum)
./build/oms-wallet create-wallet

# Sign message
./build/oms-wallet sign-message --chain-id 80002 --message test

# Verify signature
./build/oms-wallet verify-signature --chain-id 80002 --wallet-address 0xb7461CcfFfc7378747C6f82804E4dEc04b9E6148 --message test --signature 0x...

# Send transaction
./build/oms-wallet send-transaction --chain-id 80002 --to 0xE5E8B483FfC05967FcFed58cc98D053265af6D99 --value 0

Homebrew version release

1. Create a tag and version release on GitHub
2. Reference the .tar.gz file url from the release inside the Formula/wallet.rb file
3. Compute the file hash curl -L <url.tar.gz> | shasum -a 256
4. Replace the sha256 value inside wallet.rb with the hash from the latest release
5. Create a PR and merge it into master

Homebrew installation

Homebrew is the macOS CLI distribution path.

# Remove tap if needed
brew untap 0xsequence/c-sdk

# Create tap, then install
brew tap 0xsequence/c-sdk https://github.com/0xsequence/c-sdk/
brew install 0xsequence/c-sdk/wallet