Supported wallets
Works with the multisigs you already use
Cosigni plugs in as a co-signer on Safe and Ready without any vault migration. Hardware wallets remain your primary keys.
Self-custody, taken to the next level
Your hardware wallet signs blind. Cosigni is the AI co-signer that analyzes the raw calldata before anything moves.
Why 2-of-3
Even on a hardware device, one key is one blind signature away from being drained. The 2-of-3 setup adds an AI co-signer and an offline backup key alongside your hardware wallet, so no single key can ever move your funds.
Any two keys move funds. No single key, and never Cosigni alone.
How it works
Cosigni creates a dedicated signer, links it to your multisig, pulls pending requests from Safe or Ready, then shows an AI safety check before any signature is submitted.
The backend generates an EVM or Starknet signer for your account and stores the private key encrypted with AWS KMS. You see only the public signer metadata in the app.
You add the signer as an owner in your multisig, then save that Safe or Ready address in Cosigni so it knows where to look for pending requests.
The app fetches unexecuted Safe transactions or Ready requests, builds a raw preview, and sends that payload to Claude for a heuristic safety verdict with confidence and reasoning.
When you press Sign, Cosigni loads the key, signs the pending request, and posts the signature back. It recomputes the transaction hash first and refuses mismatches.
Case study
Attackers injected malicious JavaScript into Safe's hosted frontend. Signers saw a routine internal transfer while the payload sent for signing replaced the wallet's logic module via delegatecall. Cosigni would have surfaced the raw calldata and flagged the mismatch before its signature was submitted.
Live preview
Pick a pending request and watch Cosigni surface the raw payload, run an AI safety check, and show whether the co-signature should proceed. No sales call or waitlist.
Representative demo data. Connect your Safe or Ready account in the hosted app for live pending request reviews.
Security for self-custody
EVM Safe and Starknet Ready co-signing with raw pending previews and AI safety assessment for personal vaults, trading wallets, and long-term holdings.
Cosigni generates a standard EVM or Starknet signer, stores the private key encrypted with AWS KMS, and submits a signature as one owner in your multisig.
Cosigni supports both EVM Safe and Starknet Ready flows today, with chain-specific signer generation, pending request previews, and signature submission paths.
Cosigni displays the raw pending transaction payload, sends it to Claude for a heuristic safety assessment, and returns a safe/caution verdict with confidence and reasoning.
Function-level decoding for approve, transferFrom, delegatecall, and other contract calls is coming soon. Today, Cosigni shows the raw pending payload and sends it to the AI safety check.
Fork simulation is coming soon. The current implementation previews pending Safe or Ready requests, runs an AI safety assessment, and keeps signing as an explicit user action.
Spend limits, allowlisted destinations, velocity rules, and deterministic ERC-20/NFT approval checks are coming soon.
Supported wallets
Cosigni plugs in as a co-signer on Safe and Ready without any vault migration. Hardware wallets remain your primary keys.
Start free
You already own the hard part: the keys. Add Cosigni to your Safe or Ready multisig and take your self-custody to the next level, free.
