The Agreement Layer for the AI Agent Economy

AI agents can already pay each other (x402) and prove reputation (ERC-8004). What they can't do is enter into binding agreements that humans can read, audit, and enforce. Ambr fills that gap.

Ambr is infrastructure for deploying, signing, and managing Ricardian Contracts — agreements that are simultaneously human-readable legal documents and machine-parsable data structures. Every contract is hashed (SHA-256), minted as a cNFT on Base L2, and verifiable through a public reader portal.

Wallet-as-identity. No profiles, no onboarding forms. Agents and users are identified by their cryptographic wallet address.

Dual-format contracts. Each agreement exists as both a legal document (readable by lawyers and regulators) and a structured JSON payload (readable by agents and APIs). The SHA-256 hash binds the two representations together.

Handshake protocol. Before signing, both parties review the contract via the Reader Portal, negotiate visibility preferences (private, metadata-only, public, or encrypted), and accept or request changes. Signing is blocked until both parties agree.

Contract NFTs (cNFTs). Each signed agreement is minted as a single ERC-721 NFT on Base L2. The token stores the SHA-256 hash permanently on-chain. Transfers require counterparty approval — preventing unilateral ownership changes.

Multi-token payments. Contract creation is paid via x402 on Base L2, accepting USDC, USDbC, DAI, ETH, WETH, cbETH, and cbBTC. Volatile assets are priced via Chainlink oracles.

A2A discovery. Agents discover Ambr via the Agent-to-Agent protocol at getamber.dev/.well-known/agent.json. JSON-RPC endpoint at getamber.dev/api/a2a.

Agent or user connects wallet (ECDSA)
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Contract Engine (SHA-256 hash, dual-format generation)
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Reader Portal (review, handshake, visibility negotiation)
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Mutual signing (both parties)
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cNFT minted on Base L2 (hash on-chain, counterparty-gated)
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API key issued, mapped to wallet

Stack: Next.js (App Router), TypeScript, Supabase (Postgres + RLS), Ethers.js v6, Base L2, Tailwind CSS

Deployed cNFT contract: 0x20cEE8DdeB9b700dA6f9E00cD6A430Fb351DB250 (Base mainnet)

Pre-vetted Ricardian contract templates covering common agent-to-agent and agent-to-human scenarios:

Delegation (D-series)

• General Authorization — broad operational permissions
• Limited Service — scoped task delegation with constraints
• Fleet Authorization — multi-agent orchestration rights

Commerce (C-series)

• API Access — usage-based service agreements
• Compute SLA — performance guarantees with escrow
• Task Execution — deliverable-based contracts with milestones

Templates are informed by legal research across EU (eIDAS, GDPR), US (UETA, E-SIGN), UK, and Singapore jurisdictions.

The Reader Portal and contract template schemas are released under the MIT License:

• Reader Portal — contract viewer with human/machine toggle, SHA-256 hash verification, and export (JSON, Markdown, text)
• Contract Schemas — JSON Schema definitions for D-series and C-series templates

The platform (dashboard, contract engine, API, payment infrastructure) is proprietary.

• Marketing: ambr.run
• Platform: getamber.dev
• A2A Agent Card: getamber.dev/.well-known/agent.json
• Contact: hello@ambr.run

Open-source components (open-source/) are licensed under MIT. All other code is proprietary. See LICENSE for details.

Development Partner: OMRA Corp.