# Probarion docs > Guides, references and verify-it-yourself recipes for Probarion, a mandate layer that lets AI agents pay on NEAR only inside limits an owner signed. You sign the limits in a NEAR contract, the agent pays inside them, and every payment is on chain for anyone to check. Reviewed: 2026-11-09 · Built from: 4ab41ca1436589c22073fa842ee46f970415e3d5 Canonical page: https://probarion.xyz/docs **Popular searches** - [mandate fields](https://probarion.xyz/docs/concepts/mandates.md) - [PROBARION:NoMandate](https://probarion.xyz/docs/build/errors.md#NoMandate) - [verify --offline](https://probarion.xyz/docs/trust/verify-a-vault.md) - [unconfirmed](https://probarion.xyz/docs/build/spend-outcomes.md) **[What Probarion is, in one payment](https://probarion.xyz/docs/start/how-one-payment-works.md)** (New here · 5 min) Follow one payment from the owner's mandate to the contract's decision and a record its owner can publish for anyone to check. No wallet needed. [What is Probarion](https://probarion.xyz/docs/start/what-is-probarion.md) **[Set up a vault and your first mandate](https://probarion.xyz/docs/start/owner-quickstart.md)** (Owner · 10 min) Sign in with a NEAR wallet, create a testnet vault, fund it with test USDC, add an agent key and sign the limits. **[Let your agent request its first spend](https://probarion.xyz/docs/start/developer-quickstart.md)** (Developer · 15 min) Build the SDK from source, run one payment on testnet and branch on the seven statuses `process()` returns. **[Check it without a wallet](https://probarion.xyz/docs/start/evaluate-in-5-minutes.md)** (Evaluator · Don't trust us) Ask the contract in your browser, then run the verifier on a signed test ledger and read the testnet vault on chain. [Verify a vault yourself](https://probarion.xyz/docs/trust/verify-a-vault.md) ## What happens to one invoice The model may advise. Code decides. The contract has the last word. 1. **Owner** Signs a mandate: who gets paid, how much per payment and in total, how many times, until when, which agent key may use it, and above what amount a person must approve. 2. **Code** Decides to allow the payment, hold it or refuse it, with built-in rules that cannot be removed. A model may advise, but it cannot widen the mandate. The SDK signs the decision into the ledger before anything is sent, refusals included. If code refuses, nothing is sent. 3. **Agent** Asks to spend. Its `spend` request carries a mandate id, an amount, a ref and two hashes, one of them the signed decision's. It has no field for a payee. 4. **Contract** Runs 14 checks in a fixed order. It pays the mandate's payee, holds the spend for an approver, or refuses with a code such as `NoMandate`. The SDK signs that outcome into the ledger. 5. **Anyone** Checks a published record. Each ledger entry is chained by hash to the one before, and the SDK anchors the root on the vault with the ledger key. The verifier runs checks a to i with no account and ends with PASS, FAIL or UNPROVEN. Follow the whole path in [How one payment works](https://probarion.xyz/docs/start/how-one-payment-works.md), or see each check in [How a payment is checked](https://probarion.xyz/docs/concepts/payment-checks.md). ## Popular guides The ideas behind every payment, one page each. New words are in the [glossary](https://probarion.xyz/docs/resources/glossary.md). **[Write a mandate](https://probarion.xyz/docs/concepts/mandates.md)** Every field, what the contract checks when the owner signs one, and why a mandate is never edited. **[Approve a held payment](https://probarion.xyz/docs/concepts/holds-and-approvals.md)** What puts a payment on hold, who may approve or reject it, and what happens when the hold expires. **[Give each agent its own key](https://probarion.xyz/docs/concepts/vaults-roles-and-keys.md)** Who may call what: the owner, the approvers, the spend-only agent key and the anchor-only ledger key. **[Why the agent cannot name a payee](https://probarion.xyz/docs/concepts/why-spend-has-no-payee.md)** A spend request has no address field. The vault pays the payee the owner set in the mandate. **[Read the signed ledger](https://probarion.xyz/docs/concepts/ledger-and-anchors.md)** How each decision is signed into a hash-chained ledger before money moves, and how anchors pin it on the vault. **[Read the security model](https://probarion.xyz/docs/trust/security-model.md)** Who holds which key, what the vault enforces whatever the off-chain code does, and the known gaps. ## Build on it The SDK, the core library, the CLI and the MCP server are on npm, at 0.1.1. A clone of the repository builds them from source too. **[Install the packages](https://probarion.xyz/docs/build/install.md)** Install the SDK, the core library and the CLI from npm, or build them from a clone. `@probarion/sdk` **[Let an agent pay](https://probarion.xyz/docs/build/let-an-agent-pay.md)** One payment cycle with the SDK: decide, sign the decision, check, spend, record the outcome. `process()` **[Spend outcomes](https://probarion.xyz/docs/build/spend-outcomes.md)** The seven statuses `process()` returns, what each one means, and what to do next. `SpendOutcome` **[Errors](https://probarion.xyz/docs/build/errors.md)** Each `PROBARION:` code: what it means, which call raises it and what to do next. The SDK and HTTP errors are there too. `PROBARION:OverPerPayment` ## Docs your agent can read **For AI agents and their builders** Every page is also plain Markdown. Point a coding agent at the index, or paste a page into a chat. - [/llms.txt](https://probarion.xyz/llms.txt): the index - [/llms-full.txt](https://probarion.xyz/llms-full.txt): every page in one file - [/docs/concepts/payment-checks.md](https://probarion.xyz/docs/concepts/payment-checks.md): one page [For AI agents](https://probarion.xyz/docs/resources/for-ai-agents.md) ## What works today, and what does not Live works in this deployment. Preview is built but not yet run end to end, or not open yet. Planned is not built. | Feature | Status | Detail | | - | - | - | | Vault contract | Live | On testnet | | Offline verifier, checks a to i | Live | Shipped, on npm | | Reproducible builds | Live | Shipped | | Vault factory | Live | On testnet | | Web console: vault, keys, faucet, NEAR USDC top-up, mandate, Payables, Agent (MCP) tab, Freeze, approvals, Reject, revoke, withdraw, key removal, proof page | Live | Tried on testnet | | Web console: email alerts, Base top-up | Preview | Built, not tried yet | | Public proof page | Live | Live for the testnet demo vault | | TypeScript SDK and CLI | Live | 0.1.1 on npm | | Payables agent | Live | Live on testnet | | Live attested model run | Preview | Checked online on testnet, image not pinned | | Canary public challenge | Live | Live on testnet | | MCP server | Live | 0.1.1 on npm, run by a real MCP client on testnet | | Mainnet vault | Live | On mainnet: 1 payment, 1 refusal, no Base payout yet | NEAR testnet is live, with one small vault on mainnet, and no third party has audited this code. [What works today](https://probarion.xyz/docs/start/what-works-today.md) adds the parts this list leaves out, and [Testnet and mainnet](https://probarion.xyz/docs/start/testnet-and-mainnet.md) says what differs between the two networks.