Vision and principles

Repurpose Bitcoin data for the agentic age

Autonomous systems can already call services and submit transactions. The remaining question in many workflows is narrower: can another party inspect the evidence, reproduce the relevant check, and understand what was not established?

Proof21 brings Bitcoin’s public history into agent-to-agent verification. Bitcoin supplies a proof-of-work reference; DMT expresses data-derived asset rules; P21 connects those foundations to evidence and acceptance policies across chains.

Choose, check, and carry the evidence

Selection binds the eligible set, rules, and source. Financial checks bind the agreed instruction to execution evidence. The receiving agent independently inspects the report and reproduces the relevant evaluation.

Design commitments

Interoperability over replacement. Preserve existing signed artifacts and source assumptions. Reuse mature infrastructure where it fits.

Bitcoin where its properties matter. A DMT interpretation or a timestamp can add a specific property. A Bitcoin reference does not make arbitrary off-chain statements true.

Open verification, useful hosted services. Keep verification usable without buying a token. Test whether customers pay for evidence collection, maintained adapters, monitoring, or supported workflows.

Broad interfaces, bounded claims. The toolkit can serve several related use cases while each report states exactly what it establishes.

Verification before token economics. The evidence model is independent of token ownership. Commercial services and any token issuance have separate release and legal requirements.

The goal is a useful common toolkit, not a claim that all agents must use P21 or that no competing infrastructure exists.

DMT resolution without minting

Proof21 uses DMT as a versioned source-interpretation profile, not as Bitcoin consensus or a universal truth engine. A DMT operation references an accepted element definition, identifies a Bitcoin block by hash and height, evaluates the supported field or pattern, and carries those inputs into a reproducible process receipt. No DMT token, mint, or per-receipt Bitcoin write is required. Bitcoin-only operations remain a separate explicit source profile.

The P21 source element is to be announced. No registration payload, chosen field/pattern, reserved name, or element inscription ID is announced here. Reusing an existing valid element is legitimate; a new branded inscription is not a prerequisite for the protocol.

Trac's standalone ord-tap supplies reusable indexing. Its pinned element parser accepts fields 4, 10 and 11, checks protocol activation, normalizes names, validates patterns and rejects duplicate names and duplicate field/pattern signatures. A new name alone does not make an already registered whole-field definition available. The reviewed parser contains no manual team-approval step; valid registration still depends on historical rule evaluation, not merely Bitcoin inclusion. Hosted provider access and service terms are separate. [1][2][6]

Initial payments: native NAT and USDC

Native NAT is a required initial commercial-launch payment method, alongside USDC on the validated x402 rail. It is not relegated to a later optional integration. The evidence protocol remains payment-agnostic: a customer chooses a supported method and independent receipt verification never requires buying NAT or a P21 token.

The native NAT profile identifies Bitcoin mainnet, TAP, the original NAT deployment inscription and its normalized fungible ticker. A token with the same symbol on another chain is a different asset unless a separately reviewed profile identifies it explicitly. Transferring a UNAT mint inscription does not transfer its fungible NAT balance. [3][4]

NAT invoices and prepaid service-credit top-ups are asynchronous: confirm an executed fungible transfer under the pinned TAP rules, then credit usage once. Subsequent small jobs consume internal non-transferable service credits; they do not each create a NAT transfer or inscription. Those credits are a service accounting record, not a P21 token, yield product or claim of trustless custody. Direct larger-job invoices can use the same settlement checks.

NAT support does not require an automatic DEX conversion. Quote fixed NAT amounts for a defined service package, or use a separately approved price policy with quote expiry and rounding. Publish network fees, minimum top-up, late/partial/overpayment, cancellation and refund rules before accepting money. No exchange rate or minimum is invented by this specification.

[1] https://digital-matter-theory.gitbook.io/digital-matter-theory/introduction/digital-elements/.element-registry

[2] https://github.com/Trac-Systems/ord-tap/blob/b8f6ea35cf6b9d405d4db7c58555e3c8ab33e8cd/src/index/updater/inscription_updater/tap/ops/dmt_element.rs

[3] https://digital-matter-theory.gitbook.io/digital-matter-theory/introduction/nat-use-cases/usdnat-method-1-live

[4] https://digital-matter-theory.gitbook.io/digital-matter-theory/introduction/non-arbitrary-tokens-nats/nat-token-transfer

[5] https://docs.x402.org/core-concepts/network-and-token-support

[6] https://github.com/Trac-Systems/ord-tap/blob/b8f6ea35cf6b9d405d4db7c58555e3c8ab33e8cd/README.md

[7] https://arxiv.org/abs/1605.04559