Chain coverage

Kryard's custody + signing + relay surface is multi-chain by stages. The honest way to read "support" is per-tier — not as a single boolean, and definitely not as "the chain appears in an address-format list." This page is the per-tier matrix.

(You may have come from the FAQ's "Which chains does Kryard support?" — the short answer lives there; this page is the long one.)

Three tiers

A blockchain is not a single capability. Kryard splits "support" into three tiers:

Tier	What it means	Who does the rest
T1 — Custody	Kryard derives the chain's address from a KMS-encrypted key, and signs arbitrary bytes with that key's curve (no transaction structure, no policy on contents).	the client builds the transaction and broadcasts it itself
T2 — Transaction	Kryard builds / serializes a chain-native transaction, enforces policy on the transaction's contents (sign only what the configured rules allow), and returns the signed payload.	the client broadcasts
T3 — Relay	Kryard broadcasts, tracks to finality, and sponsors gas — the managed product, end to end.	nobody — this is the full surface

EVM is at T3. For every other chain Kryard is at T1 only: Kryard can hold the key and sign bytes you supply, but it does not build a Solana / Tron / Sui transaction, nor relay one. The matrix below makes that explicit.

Coverage matrix

Chain	Curve	T1 — Custody + raw signing	T2 — Transaction signing	T3 — Relay (managed)
EVM (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, …)	secp256k1	✅	✅	✅ live on Sepolia testnets (Ethereum / Base / Arbitrum / Optimism / Polygon / BSC)
Solana	ed25519	✅ derive base58 address · sign raw with HASH_FUNCTION_NOT_APPLICABLE (signs the message bytes directly — Solana's wire requirement)	—	—
Tron	secp256k1	✅ base58check 0x41-prefix address · sign raw with HASH_FUNCTION_KECCAK256 (Tron hashes like EVM)	—	—
Sui	ed25519	✅ blake2b address · sign raw with HASH_FUNCTION_NOT_APPLICABLE	—	—
Aptos, Bitcoin, Cosmos, Doge, Stellar, TON, XRP, Sei, Spark	secp256k1 / ed25519 / P-256 (per native)	⚠️ address derivation only; raw signing on the curve is available but the wire shapes aren't pinned	—	—

Rows that say "address derivation only" pass through the public /signing/create_private_keys path: Kryard returns the address; nothing else is asserted.

What "T1 custody + raw signing" lets you do

For Solana / Tron / Sui today you can:

• Create a private key in Kryard's KMS-encrypted store on the right curve:
  • Solana / Sui — CURVE_ED25519
  • Tron — CURVE_SECP256K1
• Derive the chain-native address.
• Sign arbitrary bytes through sign_raw_payload:
  • Solana / Sui — pass HASH_FUNCTION_NOT_APPLICABLE (the signer signs the message bytes directly, which is exactly what Solana requires of the serialized-message signature).
  • Tron — pass HASH_FUNCTION_KECCAK256 (same shape as EVM).

After that you build the transaction and broadcast it yourself. Kryard is not part of the broadcast path for non-EVM chains.

Scope of custody + raw signing on non-EVM chains

• No transaction-policy enforcement on non-EVM raw signs. The signer re-checks that the payload matches the policy-evaluated input (the EVM path does this), but a non-EVM sign_raw_payload has no chain-semantic policy on the contents of what it signs. The raw-payload lane is gated off by default; see /signing/signing.
• No sign_transaction on non-EVM chains. A sign_transaction request that declares any non-EVM transaction type is rejected with UNSUPPORTED_TRANSACTION_TYPE — the signer never silently dispatches non-EVM bytes to the EVM path.
• No relay / sponsor / paymaster on non-EVM chains. The relay tier — RPC clients, nonce management, gas estimation, EIP-1559 + EIP-7702 broadcast — is EVM-only end to end. There is no pay-gas-in-any-token, no sponsorExecute, no 4337 paymaster lane for non-EVM chains.

Stating this honestly

The precise wording for non-EVM chains is "key custody and raw message signing," not "support." Anything stronger oversells what Kryard actually does for Solana / Tron / Sui today. create_private_keys + sign_raw_payload are available; building a transaction, enforcing transaction-content policy, broadcasting, and gas sponsorship are not.