Visa and Mastercard Co-Found 26-Member Agentic Payments Alliance as Walmart Ends NFC Holdout

Rain launched the Agentic Payments Alliance (APAAgentic Payments Alliance — a 26-member working group founded by Rain to develop shared standards for AI agent-initiated commerce transactions.) on August 18 ¹, with Visa, Mastercard, Fiserv, Circle, and the Solana Foundation among its 26 founding members. Charter members listed shared research on agent identity and authorisation frameworks, and regulatory advocacy, as near-term work. No single company controls the APA; founding members set its mission collectively. Walmart — the last major US retailer to block NFCNear Field Communication — the short-range radio standard enabling tap-to-pay at card terminals using a phone, watch, or contactless card. (Near Field Communication, the radio standard that powers tap-to-pay at card terminals) payments — confirmed Google Pay and Apple Pay acceptance starting August 24 ². All 10,500-plus US Walmart and Sam’s Club locations reach full contactless coverage by end of 2026; fuel stations follow by mid-2027. OpenAI released the Codex agent harness as open-source code on August 20 under Apache-2.0 ³. That harness — the execution layer between a model and a task — covers context gathering, tool invocation, sandbox enforcement, and multi-turn state management. Three developments in five days extended the agentic commerce infrastructure stack across standards governance, physical-world payment access, and developer tooling.

Mastercard’s “Encoding Trust” report (2026-w32) catalogued three structural gaps in agentic commerce: no persistent agent identity standard, no universal mandate format, and insufficient dispute resolution for machine-initiated orders. All three gaps have corresponding APA working items. Visa’s Trusted Agent Protocol (TAPTrusted Agent Protocol — Visa's open standard for embedding a cryptographic AI agent identity signature into payment request headers for merchant verification., Visa’s open standard for signing agent identity into payment request headers) reached commercial deployment after sandbox pilots with 100-plus partners. Agent Pay counted 30-plus live users at Mastercard’s Q2 2026 earnings call (2026-w31). Both networks made parallel infrastructure announcements across 16 weeks without a shared governance structure. Rain’s APA places Visa, Mastercard, Circle, and the Solana Foundation under a single deliberative process for the first time, alongside Rain, whose stablecoin rails are compatible with both card-network agentic token schemes. McKinsey estimates $3–5 trillion in global agentic commerce by 2030; the APA press release cites that projection as its scale context.

Walmart’s NFC shift extends agent payment reach to the full US Walmart store network for the first time. Agentic checkout frameworks — Gemini Spark (2026-w33), ChatGPT Work mode (2026-w32) — can instruct an agent to complete an in-store task via a linked digital wallet. Those flows could not reach Walmart’s 10,500-plus stores until August 24. Codex’s harness ³ adds complementary developer infrastructure. Before this release, developers building agent commerce workflows had to replicate context management, tool invocation, and approval-gate patterns independently. OpenAI’s internal data shows harness optimization raised GPT-5.6 Sol’s ARC-AGI-3A benchmark measuring AI agent ability to generalize across novel abstract reasoning tasks, used to evaluate performance independent of training data memorization. (a benchmark measuring AI generalization across novel abstract reasoning tasks) score from 13.3% to 38.3% while cutting token consumption sixfold. Apache-2.0 covers three components: codex exec, the Codex SDK, and app-server. Any developer can build a shopping agent or procurement workflow from the same harness Codex uses, without access to ChatGPT’s application layer. The harness uses declared tool schemas and streamed output consistent with the Agentic Commerce Protocol (ACPAgentic Commerce Protocol — OpenAI's open standard specifying how AI agents communicate with merchants for discovery, cart management, and checkout., OpenAI’s open standard for agent-to-merchant transactions).

Stripe published two agentic payments expansions this week. A Stripe survey of 2,300 workers in 20 countries found 57% would accept stablecoin payouts if offered ⁴. Deel, DoorDash, and Meta are among platforms already using Stripe’s stablecoin rails, with Meta extending them to Instagram and Facebook creators. Separately, an August 17 announcement extended instant in-dashboard currency conversion to 37 markets ⁵, supporting up to 18 settlement currencies without routing through an external bank first. Razorpay launched Vulcan on August 18 ⁶ — India’s first AI foundation model trained on payment transaction data — covering 3 trillion data points across 4 billion payments, with NVIDIA and AWS as infrastructure partners. Daybreak expanded on August 21 ⁷, adding GPT-5.6-Cyber for authorized vulnerability research and 16 new vendor partnerships including Cloudflare, whose Wallets infrastructure handles agent-to-service payment routing across the agentic commerce stack.