Arcium

Encrypted computation on Solana via MPC. Data stays encrypted during computation. Your confidential app — a Solana program + Arcis circuits (the Rust circuit framework) + an on-chain metadata account — is an MXE (MPC eXecution Environment). The arcium CLI (wraps Anchor) handles init, build, test, and deploy — use MCP for current flags and options.

Targets Arcium v0.11.x (Anchor 1.0.2, Solana 3.1.10 — unchanged from v0.10.x). Upgrading from v0.10.x? See the v0.10 → v0.11 migration guide — the one app-facing breaking change is queue_computation's new 7th arg callback_cu_limit: u32 (pass 0 for default). v0.11 also adds Arcis enums and Option<T> (additive; not usable as circuit input/output). Coming from v0.9.x? Do the v0.9 → v0.10 migration first (init_comp_def → init_computation_def, @coral-xyz/anchor → @anchor-lang/core, Box<…> on queue-side accounts).

MCP Tools: search_arcium_docs for discovery (returns page path), then query_docs_filesystem_arcium_docs with cat <path>.mdx for full-page reads (e.g., cat /developers/arcis/mental-model.mdx).

No MCP? Use the docs directly: docs.arcium.com/llms.txt for the page index, or llms-full.txt for all docs in one file.

When to Use

Use when:

You need trustless computation -- cryptographically guaranteed, no single party sees the data
Multiple parties compute on combined data without revealing inputs
On-chain state must remain encrypted but computable
Privacy: sealed-bid auctions, voting, hidden game state, dark pools, confidential DeFi