Magic is a mature embedded-wallet vendor whose server wallets hold keys in AWS Nitro Enclaves and sign only with a short-lived operation token. It has Solana support and enterprise SLAs. It does not have a policy engine, and its keys are exportable. For an agent, that makes it a well-guarded hot key.
Magic for your users' embedded wallets; Coldstar for your own agents and treasury.
| Coldstar | Magic | |
|---|---|---|
| Who holds the root key | You. The cold root lives encrypted on your own USB drive. No vendor holds a key, a share, or an account. | Magic's enclaves. Server wallets sign only with a short-lived operation JWT bound to the identity at creation. Private key export is supported for both embedded and server wallets. |
| Where the key lives | On your machine. The air-gapped root signs a bounded policy envelope; a disposable session key signs routine transactions inside it. | AWS Nitro Enclaves with key sharding, hosted by Magic. |
| Policy engine | Per-transaction limit, daily cap, program allowlist, recipient allowlist and blocklist, escalate-above threshold. Evaluated locally, first match wins, before any signature exists. | None found in the documentation index: no spending limits, allowlists, or policy pages. |
| Out-of-policy transactions | ESCALATE to a human over air-gapped QR, or REJECT. No signature is produced for a rejected transaction. | Not applicable; whatever holds the operation JWT can sign anything. |
| Cold / offline root | Yes — the root key never touches a networked machine. | No. |
| Agent integration | Framework-agnostic: the agent proposes an unsigned transaction, the signer decides. CLI signer today; MCP server in progress. | None documented. The only AI reference is an MCP for browsing Magic's docs. |
| Solana support | Solana mainnet. Core is chain-agnostic; EVM signing exists. | Yes: embedded and server wallets support Solana. |
| Source & self-hosting | Open source (MIT), self-hosted. No API key, no SaaS dependency, nothing to go down. | Not confirmed as open source. Hosted. |
| Pricing | Free software plus a ~$10 drive. | Free to 1,000 monthly active wallets, $0.045 per extra; Startup $99/month to 2,500; Enterprise custom, down to $0.001 per transaction. |
| Maturity | Beta — the signing core and policy engine are in scope for the planned independent audit. | Production; long-running vendor. |
Magic protects a key well. It does not decide what that key may sign. For an agent, the deciding is the whole job.
Magic's server wallets are a safe place to keep a key that your backend uses: Nitro isolation, sharding, and a short-lived JWT per operation. But there is no rule between the JWT and the signature. Compromise the backend that mints operation tokens and the enclave will sign whatever it is asked to, and the key can be exported.
Coldstar puts the rule where the signature is made. The root is offline and cannot be exported; the agent's session key is bounded by limits, allowlists, and a daily cap evaluated locally; over-threshold transactions wait for a human.
Magic is production. Coldstar is beta, pre-audit.
We found none in its documentation at review time. Limits would have to live in your backend, in front of the operation-token minting.
It protects the key from theft at rest. It does not protect the funds from an agent that has been talked into spending them, because there is no policy between the request and the signature.
The root is an encrypted file you already hold, so there is nothing to export from a vendor. It is never decrypted on a networked machine.
Open source, MIT. macOS, Linux, Windows — and on the Solana Seeker dApp Store.
pip install coldstar
Third-party facts were checked against the vendor's own pages on the date above. Pricing and feature sets change; if something here is out of date, tell us and we will fix it.