Agent-safe signing · MPC embedded wallets

Coldstar vs Para

Para is an embedded-wallet vendor with a real agents page: pregenerated wallets, transfer limits, chain restrictions, and a permissions system with default deny. Its 2-of-2 MPC assumes a human's device holds the second share. Coldstar assumes there is no human device in the loop and puts the root offline instead.

Last reviewed 2026-09-04 · Facts link to first-party sources below · Corrections welcome

Pick Para if

  • You are building a consumer app and want user wallets where the user's device is the second factor.
  • You want scoped permissions users consent to at grant time.
  • You want a hosted vendor with SOC 2 and a free tier to 1,200 monthly users.

Pick Coldstar if

  • You are running headless agents with no user device to hold a share.
  • You want policy enforced on the signing machine rather than at a vendor API layer.
  • You want an owner-held cold root and no per-user pricing.

Use both when

Para for your users' wallets; Coldstar for the agents and treasury on your side of the product.

Side by side

ColdstarPara
Who holds the root keyYou. The cold root lives encrypted on your own USB drive. No vendor holds a key, a share, or an account.2-of-2 MPC: one share on the user's device, one in Para's cloud HSMs; both needed, so Para cannot sign alone. For agent and pregenerated wallets, who holds the "user" share is not documented.
Where the key livesOn your machine. The air-gapped root signs a bounded policy envelope; a disposable session key signs routine transactions inside it.Para cloud HSMs (TEE vendor not named) plus user device.
Policy enginePer-transaction limit, daily cap, program allowlist, recipient allowlist and blocklist, escalate-above threshold. Evaluated locally, first match wins, before any signature exists.Policies → scopes → permissions, default deny: value caps, recipient allowlists, per-chain scoping, function-level restrictions. Enforced server-side before the MPC ceremony, at the API layer. Daily caps and time windows not confirmed.
Out-of-policy transactionsESCALATE to a human over air-gapped QR, or REJECT. No signature is produced for a rejected transaction.Denied. User consent at scope grant; no per-transaction human approval queue documented.
Cold / offline rootYes — the root key never touches a networked machine.No.
Agent integrationFramework-agnostic: the agent proposes an unsigned transaction, the signer decides. CLI signer today; MCP server in progress.Agents page: REST API, wallet pregeneration, transfer limits, chain restrictions, spending conditions; customers include ElizaOS. Solana Agent Kit ships a Para example.
Solana supportSolana mainnet. Core is chain-agnostic; EVM signing exists.Yes: EVM, Solana, Cosmos; Swig smart-account integration on Solana.
Source & self-hostingOpen source (MIT), self-hosted. No API key, no SaaS dependency, nothing to go down.SDKs public; MPC code closed. Hosted.
PricingFree software plus a ~$10 drive.Free to 1,200 monthly active users; Starter $200/month (2,500); Growth $500/month (10,000); Scale $1,000/month (25,000); Enterprise custom.
MaturityBeta — the signing core and policy engine are in scope for the planned independent audit.Production; SOC 2 Type II.

Para's design makes the most sense when there is a human whose phone holds the second share. Agents do not have phones. That is the whole gap Coldstar is built to fill.

Where each one wins

Where Para wins

  • User-centric MPC. The user's device is a real second factor for consumer wallets.
  • Consent UX. Scopes users approve, with default deny.
  • Free tier that covers early consumer traction.

Where Coldstar wins

  • Built for headless. No user share required; the offline root and a disposable session key are the two factors.
  • Local enforcement. Policy runs on the signing machine, not at a vendor's API boundary.
  • No MAU pricing. Free software.

What you are actually trusting

Para splits the key between a user's device and its HSMs and evaluates permissions server-side before the signing ceremony. For a consumer wallet that is sensible: the user's phone is a real second factor. For an agent, the question is who holds the device share, and Para's docs do not say.

Coldstar's two factors are the offline root and the disposable session key it authorises. The policy that bounds the session key is evaluated locally, before a signature exists; the root never goes online.

Para is production and SOC 2 certified. Coldstar is beta, pre-audit.

Frequently asked questions

Who holds the second MPC share for a Para agent wallet?

Para's docs describe the user-device share for consumer wallets; for pregenerated and agent wallets the holder of that share was not documented at review time.

Where does Para enforce policies?

Server-side, before the MPC signing ceremony, so they cannot be bypassed client-side. That is an API-layer control. Coldstar enforces policy on the signing machine itself.

Can I use Para and Coldstar together?

Yes, in different places: Para for your users' embedded wallets and Coldstar for your own agents and treasury.

Try Coldstar in two minutes

Open source, MIT. macOS, Linux, Windows — and on the Solana Seeker dApp Store.

pip install coldstar

Related comparisons

Sources

  1. Para security (2-of-2 MPC, HSMs, SOC 2)
  2. Para permissions concepts
  3. Para for agents
  4. Para pricing
  5. Para: Solana smart accounts (Swig)

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.