Protocols
MPP, Payment Auth, HTTP 402, x402, specifications, and revision-level changes.
SANDBOX LABS AI · RESEARCH BRIEF
MPP Pulse
Weekly intelligence on the machine-payments layer: MPP, Tempo, x402, Payment Auth, HTTP 402, and the infrastructure making agent-to-agent commerce possible.
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01
Current Pulse
LATEST BRIEF · WEEK ENDING SEPTEMBER 13, 2026
IETF Payment Auth adds an XRP Ledger payment method.
After last week's flat record, this one has a real material development: the IETF Payment Auth spec gains an `xrpl` payment method for the XRP Ledger, covering both one-time charges and off-ledger session intents. The rest of the week was specification hygiene — new problem URIs, a Datatracker-triggered draft renewal, title-case cleanup, and a documentation sync with mppx's own main branch — plus one genuine Tempo ecosystem announcement (Wirex live on Tempo) and a handful of self-reported x402 projects named and left there.
Signal A substantive expansion of the IETF Payment Auth spec set with the addition of the `xrpl` payment method, including charge and session intents, broadening the suite's coverage of decentralized finance use cases.
Evidence The `xrpl` method merged into the core spec and documentation, four new problem URIs formalized in the core spec, a Datatracker-triggered draft renewal to revision `-01`, and a documentation sync covering deferred EVM signing, MCP multi-offer composition, and Challenge-ID-bound subscriptions.
Watch next Whether an `xrpl-mpp-sdk` implementation shows up correctly handling both charge and session intents, or the method stays spec-only for now.
Read last week's report — MPP makes its spec releases immutable and vendors its CI actions.
02
What it watches
Implementation
Repository activity, merged pull requests, releases, tags, and verifiable deployment evidence.
Adoption
Official announcements, integrations, payment rails, and machine-commerce infrastructure.
Evidence
Primary sources first. Community discussion is context, never proof by itself.
03
Why it exists
Machine payments are becoming an infrastructure layer for agents. The useful evidence is scattered across specifications, code, company announcements, and developer activity. MPP Pulse turns that movement into a short, cited weekly read.
Sources→Collection→Evidence gates→Human review→Weekly brief
04
Built in public
MPP Pulse began as an always-on AWS agent: EventBridge Scheduler triggers one Lambda; the agent collects, scores, and stores evidence; Amazon Bedrock prepares a cited report. The public project is open source, while the research workflow stays deliberately human-reviewed.