SKILLoptionalHermes Optional Skills

Mpp Agent

Name: Mpp Agent
Author: Teknium (teknium1), Hermes Agent

Pay HTTP 402 APIs via Machine Payments Protocol (MPP)

PaymentsMPPHTTP-402TempoStripeOptionalHermes skill

Last registry verification2026-08-18v0.1.0Teknium (teknium1), Hermes Agent

Open original source ↗اقرأ بالعربية

Plain meaning

What does it add to Hermes?

Pay HTTP 402 APIs via Machine Payments Protocol (MPP)

Mpp Agent is a skill related to payments and business operations. It handles financial or commercial data and actions; any write operation needs stronger approval and limits than ordinary use.

This plain-language explanation is based on the publisher description. The original text remains visible for verification.

Use it when

Use it when your goal in payments and business operations is clear and you can limit it to the data and actions it actually needs.

Skip it when

Do not add it merely to experiment when Hermes already has a simpler path, or when you cannot review its source and permissions.

Who is it for?

Best for users who want a repeatable way of working inside Hermes.

Safe first test

Use a sandbox or test data and do not grant real payment or refund permissions in the first test.

Original publisher description

Pay HTTP 402 APIs via Machine Payments Protocol (MPP)

✓

Data source

This entry was indexed from Hermes Optional Skills. Our explanation interprets the type and domain without inventing a capability not present upstream.

Security review

The source is official or editorially reviewed, but you still need to review permissions and version compatibility.

Safe setup path

Inspect, install, then test.

01
Open the source
Match the publisher, license, and description to your need. Check the real update history.
02
Review permissions and secrets
Never paste a secret value into this site. Use environment-variable names and grant the smallest scope.
03
Copy setup only after review
The controls below copy text. They do not execute commands on your device.
04
Test with a non-sensitive task
Inspect the visible tools, then exclude write or delete tools you do not need.

Install command

Review the command, then copy it.

hermes skills install mpp-agent

Hermes Belarabi does not execute this command. Installation happens on your device and remains subject to Hermes scanning and your review.

The full skill definition

Exactly what Hermes loads when this skill runs.

Reproduced from the official documentation. Read it before enabling the skill: this text becomes the agent's instructions.

Pay HTTP 402 APIs via Machine Payments Protocol (MPP).

Skill metadata

A lookup table. Do not read it all; find the row that applies to you.

Source	Optional — install with `hermes skills install official/payments/mpp-agent`
Path	`optional-skills/payments/mpp-agent`
Version	`0.1.0`
Author	Teknium (teknium1), Hermes Agent
License	MIT
Platforms	linux, macos
Tags	`Payments`, `MPP`, `HTTP-402`, `Tempo`, `Stripe`
Related skills	`stripe-link-cli`, `stripe-projects`

Reference: full SKILL.md

Explains the idea itself. Read it slowly; the later sections build on it.

Wraps the Machine Payments Protocol (MPP, https://mpp.dev) clients so Hermes can pay for per-request API access against servers that respond with HTTP 402 Payment Required.

Three client options, all distributed via npm. Pick the lightest one that solves the user's need. Gated [linux, macos] while the broader payments tooling matures on Windows.

When to Use

Explains the idea itself. Read it slowly; the later sections build on it.

A merchant API returns HTTP 402 with a www-authenticate header — and the user wants to actually pay it, not just log the response.
The user asks to "pay per request", "set up an agent wallet", "use Tempo / Privy / AgentCash", or wants to discover MPP-priced services.
A Stripe Link spend has produced a Shared Payment Token (SPT) and the agent needs to attach it to the 402 challenge — in that flow, prefer link-cli mpp pay (see the stripe-link-cli skill).

Choosing a client

A lookup table. Do not read it all; find the row that applies to you.

Tool	When	Setup
`link-cli`	User already has Stripe Link set up, or the 402 challenge advertises `method="stripe"`	see the `stripe-link-cli` skill
Tempo Wallet	MPP services with spend controls, service discovery	`tempo wallet login`
Privy Agent CLI	Multi-chain wallets, browser-based funding	`privy-agent-wallets login`
AgentCash	300+ pre-priced APIs via one USDC.e balance	`npx agentcash onboard`
`mppx`	Dev + debugging, smallest dep surface	`npm install -g mppx` then `mppx account create`

Default: if the user already has Stripe Link configured or the 402 challenge specifies method="stripe", use link-cli mpp pay (the stripe-link-cli skill). Otherwise mppx for one-off paid calls and debugging, and Tempo Wallet when the user wants persistent spend controls.

Prerequisites

Explains the idea itself. Read it slowly; the later sections build on it.

Node.js 20+ on PATH
A funded wallet (Tempo / Privy / AgentCash) OR an mppx account
For Tempo / Privy / AgentCash: follow their respective onboarding skills:
https://tempo.xyz/SKILL.md
https://agents.privy.io/skill.md
https://agentcash.dev/skill.md

Use web_extract to fetch any of those SKILL.md files if the user picks one.

Procedure (mppx, fastest path)

Explains the idea itself. Read it slowly; the later sections build on it.

Run all commands through the terminal tool.

1. Install + create an account

Text2 lines

npm install -g mppx
mppx account create

Store the resulting account credentials wherever the CLI tells you (the CLI writes them under its own config — do not paste them into the agent transcript).

2. Inspect the merchant's 402 challenge

If the user gives you a URL, probe it first to confirm it actually speaks MPP:

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curl -i <url>

A real MPP 402 looks like:

Text2 lines

HTTP/1.1 402 Payment Required
www-authenticate: tempo amount=0.1 currency=...

3. Pay the request

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mppx <url>

For non-GET methods or request bodies:

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mppx <url> --method POST --data '<json>'

mppx handles the 402 challenge/credential dance automatically and prints the merchant's actual response on success.

4. Verify the receipt

mppx attaches the receipt header automatically. To inspect:

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mppx <url> -v

Procedure (Tempo Wallet)

Explains the idea itself. Read it slowly; the later sections build on it.

The Tempo Wallet skill at https://tempo.xyz/SKILL.md is the canonical reference; fetch it with web_extract and follow it. Headline:

Text2 lines

tempo wallet login
tempo wallet pay <url>

Spend controls and service discovery live in the wallet UI at https://wallet.tempo.xyz.

Pitfalls

Explains the idea itself. Read it slowly; the later sections build on it.

HTTP 402 without method="stripe" cannot be paid by Stripe Link. If the challenge advertises only Tempo / other methods, use mppx (or whichever wallet matches) — Link will reject it. Conversely, if it advertises method="stripe", prefer Link via the stripe-link-cli skill so the spend goes through the user's approved card.
Multiple challenges in one header. www-authenticate may list several methods (e.g. tempo, stripe). The Link CLI's mpp decode will pick the Stripe one; mppx will pick Tempo. There's no single "right" client — pick by which wallet the user has funded.
Zero-amount challenges. Some MPP endpoints charge $0.00 and just want a proof credential. These work without a funded wallet. Don't refuse them as "broken."
Wallet keys never enter agent context. All four clients store keys under their own config dirs (or generate per-session ephemeral keypairs, in Privy's case). Do not cat/read_file them.
Server-side MPP is a different skill. If the user wants to ADD 402 to their own API, this skill is wrong — point them at https://mpp.dev/quickstart/server and the mppx/nextjs / mppx/hono / mppx/express / mppx/elysia middlewares. A dedicated mpp-server skill may land later.

Verification

Explains the idea itself. Read it slowly; the later sections build on it.

Text1 line

mppx --version && mppx account list

Exit code 0 means installed and an account exists.