> For the complete documentation index, see [llms.txt](https://docs.10102.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.10102.io/architecture.md). # Architecture 10102 Computing Legacy is deliberately layered so that the **on-chain layer is self-sufficient**, and the **off-chain layer is strictly additive**. If the off-chain services disappeared tomorrow, every existing legacy and timelock would still function — you'd lose email reminders and the pretty UI, but you'd keep the plan. ## The layers ### 1. On-chain: the core plan Solidity contracts on Ethereum. Deployed behind upgradeable proxies owned by a Safe multisig. Verified on Etherscan and published at [github.com/10102-io/computing-sc](https://github.com/10102-io/computing-sc). * **Legacy routers** — `MultisigLegacyRouter`, `TransferLegacyRouter` (Safe owners), `TransferEOALegacyRouter` (plain EOAs). * **Timelock router** — `TimeLockRouter`. * **Per-user legacy contracts** — deployed deterministically via `LegacyDeployer` using `CREATE2`, so the address is predictable before deployment. * **Safe integration** — a Safe Guard tracks last-activity timestamps; a Safe Module executes activation (adding owners or transferring assets). * **Premium contracts** — `PremiumSetting` stores watcher/reminder configuration (addresses only — reminder emails live off-chain); `PremiumRegistry` records subscriptions; `PremiumReminderView` is a standalone read-only contract the reminder service polls for due reminder windows. Full address list, for every deployed contract and network, lives in `contract-addresses.json` of the `computing-sc` repository. ### 2. Indexing: The Graph A single subgraph per chain provides fast, reliable read access to the parts of the system that would be painful to query from raw RPC: * **Legacy/timelock/reminders subgraph** — indexes every event emitted by the routers and 10102-enabled Safes: creations, edits, deletions, activations, reminder configurations, and the PII-free `LegacyEmailNotifyRequested` notify events (as `NotifyRequested`) that the off-chain reminder worker consumes. The UI reads the bulk of its state from here. Everything else is direct on-chain. Token balances for the "your assets" pickers during legacy creation are fetched via viem against the canonical `TokenWhitelist` contract plus per-token ERC-20 `balanceOf` (`src/services/web3-assets-service.ts`). System-wide aggregates (total value locked across all legacies, timelocks and 10102-enabled Safes) are computed by the admin panel via `Multicall3` plus ERC-20 `balanceOf` / `allowance` walks against the entity set returned by the subgraph — see the `computing-admin` repository for the implementation. The UI prefers subgraph reads for the indexed data but falls back to direct on-chain reads (via viem) for post-mutation freshness, so stale subgraph data never blocks a newly-valid action. ### 3. Off-chain services Strictly additive layers that improve UX but can fail without breaking the plan: * **Chainlink Functions** — bridges Moralis API data into on-chain activation checks for EOA legacies (where the EVM can't natively read a wallet's last-tx timestamp). * **Reminder worker** — an off-chain service (Railway + Postgres) that drives email reminder evaluation and delivery. It reads PII-free notify events from the subgraph plus a read-only on-chain "due" view (`PremiumReminderView`), keeps recipient emails encrypted off-chain, and sends through the mail service. This **replaces the retired Chainlink Automation cron and Chainlink Functions email path** (decommissioned on mainnet 2026-06-02). * **Mailjet** — SMTP delivery for reminder emails, behind the 10102 mail proxy the worker posts to. * **Public RPC providers + Etherscan** — fallback read paths the UI can switch to. ## Section index * [Legacy Contracts Created with Safe SDK](/architecture/legacy-contracts-created-with-safe-sdk.md) — how Multisig and Safe-backed Transfer legacies work, including the Safe Guard and Safe Module integration. * [Legacy Contracts Created with EOAs](/architecture/legacy-contracts-created-with-eoas.md) — how pure-EOA Transfer legacies work, including the approval model and CREATE2 deployment. * [New Account Generation for Beneficiaries](/architecture/new-account-generation-for-beneficiaries.md) — client-side keypair generation for beneficiaries without an Ethereum address. * [Indexing & Activity Tracking](/architecture/indexing-and-activity-tracking.md) — how The Graph and the hybrid Chainlink/Moralis path feed the app. * [Email Reminders](/architecture/email-reminders.md) — the off-chain encrypted reminder-worker that sends out-of-band notifications (replacing the retired Chainlink path). ## A note on upgradeability Every contract deployed by 10102 sits behind a transparent upgradeable proxy whose admin is a Safe multisig held by the 10102 team. We can patch bugs and ship improvements — we *cannot* silently drain assets or retroactively alter an existing legacy's terms. Beneficiaries, owners, allocations, and activation windows are stored in per-legacy state that upgrades leave intact. Migration to a community-governed admin is on the public roadmap.