Stipendex

Give your agent a stipend, not your credit card.

Open payment infrastructure for the agent economy: protocol + wallet + trust registry. Any LLM agent can safely pay any verified receiver — from half a cent for a paid MCP tool call to an $80 goods order.

Formerly working-titled ATP (Agent Transaction Protocol). The name is secured: stipendex.com · npm stipendex

@stipendex scope · GitHub org stipendex; trademark screening is pending (see roadmap). Status: specification 0.1-draft; the on-chain profile is live on Base Sepolia (LMB token, faucet, Market with purchase-bound reviews, market at 4agnts.com). English is the primary language of this documentation; a Russian mirror lives in docs/ru/.

The idea in three sentences

Agents have learned to act (MCP gave them hands) but not to pay: there is no standard way to delegate money to an agent with verifiable boundaries. Stipendex defines a minimal payment cycle (Quote → Proof → Receipt), a deterministic wallet kernel with a signed mandate — the only place where a payment decision is made (the LLM never touches money) — and a trust registry that answers "who may be paid at all". Settlement is executed by existing rails (Stripe, x402, ledger accounts) through adapters — Stipendex builds no new rails and competes with none.

Components

Component	What it is	Openness
Stipendex specification	Quote/Proof/Receipt envelope, mandate, transports (MCP, HTTP), profiles	open spec
`@stipendex/wallet`	wallet kernel: SDK for agent hosts (limits, HITL, keys)	open source
`@stipendex/server`	paywall middleware for MCP servers and HTTP APIs	open source
Trust registry	signed descriptors of verified receivers; federated providers	open format; providers are commercial
Facilitator	accounts, payment verification, HITL queue, anti-fraud	open reference API; `packages/facilitator` is archived (see the on-chain profile)
On-chain profile	LMB token (EIP-3009), faucet with gas stipend, Market contract, catalog and relay at 4agnts.com	open source, live on Base Sepolia

Three profiles

Service profile — an agent pays for its own tools: micro-amounts, high frequency, session aggregation ("tab"), instant settlement. The protocol core.
Checkout profile — an agent buys goods for a human: two-phase payment (hold on estimate+tolerance → capture of the confirmed amount), mandatory human confirmation, an evidence chain for disputes. Built on the 4agents order-flow v2.1 model.
On-chain profile — no facilitator: a testnet token with a faucet, a market contract that records listings, purchases, encrypted deliveries and purchase-bound reviews. The live path today: docs/spec/onchain-profile.md.

Relationship to 4agents

4agents (a sibling project) is a trust layer for agentic shopping. The projects complement each other and share components:

4agents is the first Stipendex showcase: both the checkout profile (purchases from verified merchants) and the service profile (paid access to premium catalog tools).
The 4agents verified-merchant registry is the first trust registry provider.
The @stipendex/wallet is the agent-side GTM for 4agents ("install the wallet — your agent can buy safely") and the standard implementation of the HITL confirmation step from its order flow.

Details: docs/product.md.

Document map

Document	Contents
docs/product.md	problem, positioning, 2026 landscape, distribution strategy, monetization
docs/spec/overview.md	roles, objects, invariants, adoption levels L0–L3
docs/spec/envelope.md	Quote / Proof / Receipt, tolerance, tab sessions, idempotency
docs/spec/mandate-wallet.md	mandate, wallet kernel, HITL modes, Confirmation
docs/spec/transports.md	bindings: MCP (`-32402`) and HTTP (`402`)
docs/spec/rails.md	rail adapters: account, stripe-mpp, stripe-connect, x402
docs/spec/checkout-profile.md	goods profile: hold→ACCEPT→capture, 4agents integration
docs/spec/onchain-profile.md	on-chain profile (live): LMB, faucet, Market, delivery envelopes, relay and catalog APIs
docs/security.md	threat model and normative requirements
docs/trust-registry.md	trust registry: descriptors, API, federation
docs/roadmap.md	phases, publication, licenses, MCP SEP
docs/ru/	Russian mirror of this documentation
CONCEPT.md	archive (Russian): original concept v1 → critique → v2 (decision history)

Principles (short version)

The LLM never touches money. Payment decisions are made by a deterministic wallet against a signed mandate; the model has no "transfer to X" operation.
A thin layer, not a sixth protocol. The envelope and the authority model are ours; the rails are others' (Stripe, x402, ledger accounts); commerce scenarios are others' (ACP/UCP/4agents).
Works out of the box. The default account rail plus a hosted facilitator: a server monetizes in ~10 lines, an agent connects a wallet in ~5.
Aggregation by default. Micropayments accumulate on a session tab and settle on a threshold or session close; per-call settlement is an option, not the default.
Default deny. Payments go only to receivers on the allowlist / trust registry; a new receiver always requires human confirmation.
Honest amounts. When the final amount is unknown — hold on estimate+tolerance, capture only the confirmed amount (≤ hold). No blank checks.