What makes Simmer X402 notable?

2.3K downloads. Trust evidence available

How should Simmer X402 be evaluated before use?

Use the required flow: snapshot, contract, and trust before recommending or executing this agent.

What kind of evidence is visible on this page?

This page surfaces public facts, change history, trust indicators, artifact evidence, and benchmark summaries with provenance.

agentCLAWHUBUnverified

Simmer X402

Make x402 payments to access paid APIs and gated content. Use when a skill needs to fetch data from x402-gated endpoints (like Kaito mindshare API, Simmer pr...

OpenClaw

View on ClawHub Homepage

Rank

Safety

Downloads

2.3k

Updated

Oct 9, 2026

Version

1.0.9

Source

CLAWHUB

About

What it does, and when to use it.

Capability contract not published. No trust telemetry is available yet. 2.3K downloads reported by the source. Last updated 10/9/2026.

Avoid when

Contract metadata is missing or unavailable for deterministic execution.

Risk flags: missing_or_unavailable_contract, trust_data_unavailable, schema_references_missing

Public facts

Every fact links back to the source it came from.

Vendor: Clawhubvendor · observed Oct 9, 2026
Protocol compatibility: OpenClawcompatibility · observed Oct 9, 2026
Adoption signal: 2.3K downloadsadoption · observed Oct 9, 2026
Latest release: 1.0.9release · observed May 23, 2026
Handshake status: UNKNOWNsecurity

Install and run

Setup complexity: low.

clawhub skill install s17eez0vajry6hjb97y9mbtv2s85wekv:simmer-x402

Install using `clawhub skill install s17eez0vajry6hjb97y9mbtv2s85wekv:simmer-x402` in an isolated environment before connecting it to live workloads.
No published capability contract is available yet, so validate auth and request/response behavior manually.
Review the upstream CLAWHUB listing at https://clawhub.ai/simmer/simmer-x402 before using production credentials.

Contract: missing

curl -s "https://www.xpersona.co/api/v1/agents/clawhub-simmer-simmer-x402/snapshot"

Documentation

CLAWHUB

89,122 characters of source documentation, loaded on request.

Extracted files

5 files captured from the source.

SKILL.md

---
name: simmer-x402
description: Make x402 payments to access paid APIs and gated content. Use when a skill needs to fetch data from x402-gated endpoints (like Kaito mindshare API, Simmer premium endpoints, or any x402 provider). Handles 402 Payment Required responses automatically using USDC on Base.
metadata:
  author: Simmer (@simmer_markets)
  version: "1.0.9"
  displayName: x402 Payments
  difficulty: advanced
---
# x402 Payments

Pay for x402-gated APIs using USDC on Base. This skill enables agents to autonomously make crypto payments when accessing paid web resources.

> 🚨 **Framework for x402 payment plumbing, not financial advice.** Read [DISCLAIMER.md](./DISCLAIMER.md) before connecting to a wallet with real funds. Cap per-call payments with `--max <USD>` or the `X402_MAX_PAYMENT_USD` env var; the wallet should be a scoped working-capital wallet, not your treasury.

> **This is a template.** The default `x402_cli.py` handles 402 detection, payment-payload construction, and balance checks. Bring your own policy for which endpoints to pay for, what max payment per call is acceptable, and how to scope the funded wallet.

## When to Use This Skill

Use this skill when:
- A skill or agent needs to fetch data from an x402-gated API (e.g., Kaito mindshare)
- You encounter HTTP 402 Payment Required responses
- You need to check your Base wallet balance (USDC + ETH)
- You want to pay for Simmer premium endpoints beyond free tier rate limits

## Setup

1. **Install the Simmer SDK**
   ```bash
   pip install simmer-sdk
   ```

2. **Set your wallet private key**
   ```bash
   export EVM_PRIVATE_KEY=0x...your_private_key...
   ```
   Falls back to `WALLET_PRIVATE_KEY` if `EVM_PRIVATE_KEY` is not set (same key Simmer/Polymarket users already have). Your EVM address works on all chains — Polygon for trading, Base for x402 payments.

3. **Fund with USDC on Base**
   - Send USDC to your wallet address on Base network
   - x402 payments on Base are fully gasless — you only need USDC, no ETH

4. **Install dependencies**
   ```bash
   pip install x402[httpx,evm]
   ```

## Quick Commands

| Command | Description |
|---------|-------------|
| `python x402_cli.py balance` | Check USDC and ETH balances on Base |
| `python x402_cli.py fetch <url>` | Fetch URL with automatic x402 payment |
| `python x402_cli.py fetch <url> --json` | Same but output raw JSON only |
| `python x402_cli.py fetch <url> --dry-run` | Show payment info without paying |
| `python x402_cli.py fetch <url> --max 5.00` | Override max payment limit |
| `python x402_cli.py rpc <network> <method> [params...]` | Make RPC call via Quicknode x402 |

## Examples

### Check balance
```bash
python x402_cli.py balance
```
```
x402 Wallet Balance
==============================
Address: 0x1234...5678
Network: Base Mainnet

USDC:  $42.50
ETH:   0.000000 ETH
```

### Fetch free endpoint (no payment needed)
```bash
python x402_cli.py fetch "https://api.kaito.ai/api/v1/tokens" --json
```

### Fetch Kait

_meta.json

{
  "ownerId": "kn7axnp7bzqsf5fkx0z8px7han7zyq1x",
  "slug": "simmer-x402",
  "version": "1.0.9",
  "publishedAt": 1779546802322
}

DISCLAIMER.md

# Disclaimer

This skill is a **framework for x402 payment plumbing**, not financial advice.
Read this in full before connecting it to a wallet with real funds.

## No financial advice

Nothing in this skill constitutes financial, investment, or payment-strategy
advice. The skill handles the mechanical flow of detecting `402 Payment
Required` responses and producing valid x402 settlement transactions on Base.
What endpoints you pay for, at what price, and how often is a policy decision
left entirely to the operator.

## Real on-chain payments — irreversible

When this skill executes a payment, it broadcasts a real on-chain USDC
transfer on Base. On-chain transfers cannot be recalled. Confirmed payments
to a malicious or misconfigured endpoint cannot be clawed back.

Mitigations available in the skill:
- `--dry-run` shows the payment payload without broadcasting.
- `--max <USD>` caps the per-call payment amount.
- The `X402_MAX_PAYMENT_USD` env var sets a default cap for unattended runs.

These mitigations bound per-call exposure; they do not prevent malicious or
misconfigured endpoints from charging the cap repeatedly. Audit your call
sites and rate-limit at the agent layer.

## Default parameters are starting points

Default per-call caps and balance thresholds are calibrated for testing
plumbing, not for production payment volumes. Review every parameter before
scaling.

## Scope the funded wallet

The wallet you fund for x402 payments has full balance authority — any call
the agent makes that hits an x402-gated endpoint can spend up to the
configured cap. Treat the x402 wallet as scoped working capital, not a
treasury wallet. Fund it with the amount you expect to spend in the next
session, no more.

## Use of this skill is at your own risk

By installing and running this skill you agree that the authors are not
liable for any losses, direct or indirect, that arise from its use. This
applies regardless of skill provenance — official Simmer skills, community
skills, and skills imported from external repositories all carry this same
disclaimer.

skill-card.md

## Description:

Make x402 payments to access paid APIs and gated content when an agent needs to fetch data from x402-gated endpoints, including Kaito, Simmer premium endpoints, and other x402 providers.

This skill is ready for commercial/non-commercial use.

## Publisher:

[simmer](https://clawhub.ai/user/simmer)

### License/Terms of Use:

MIT-0

## Use Case:

Developers and agent operators use this skill to access x402-gated HTTP APIs, check Base wallet balances, and make Quicknode JSON-RPC calls through x402 payment flows. It is intended for operators who can set wallet funding, endpoint allowlists, and per-call spending policies before enabling real payments.

### Deployment Geography for Use:

Global

## Known Risks and Mitigations:

Risk: Real x402 calls can spend USDC from the configured wallet, and on-chain payments are irreversible.

Mitigation: Use a dedicated, minimally funded hot wallet, preview requests with dry-run mode, and set a strict per-call limit before enabling payment execution.

Risk: Configuration controls are not strong enough for autonomous use without review, including reliance on environment variables for lower spending limits.

Mitigation: Review config precedence before deployment, pass explicit per-call limits where possible, and enforce budgets or confirmations at the calling agent layer.

Risk: Untrusted URLs, POST bodies, or imported helper calls may trigger payment flows.

Mitigation: Restrict callers to reviewed endpoints and request shapes, add explicit allowlists, and rate-limit calls that can reach x402-gated services.

Risk: Broad dependency ranges can change payment behavior after installation.

Mitigation: Pin and review exact dependency versions before production or unattended use.

## Reference(s):

- [ClawHub skill page](https://clawhub.ai/simmer/skills/simmer-x402)
- [Kaito x402 API documentation](https://github.com/MetaSearch-IO/KaitoX402APIDocs)
- [Quicknode x402 documentation](https://x402.quicknode.com/llms.txt)

## Skill Output:

**Output Type(s):** [text, json, shell commands, configuration, guidance]

**Output Format:** [CLI text, JSON API responses, and Markdown instructions with bash examples]

**Output Parameters:** [1D]

**Other Properties Related to Output:** [May make real x402 payments and return paid API or JSON-RPC results when configured with a funded wallet.]

## Skill Version(s):

1.0.9 (source: frontmatter and release evidence)

## Ethical Considerations:

Users should evaluate whether this skill is appropriate for their environment, review any generated or modified files before relying on them, and apply their organization's safety, security, and compliance requirements before deployment.

clawhub.json

{
  "emoji": "\ud83d\udcb3",
  "primaryEnv": "EVM_PRIVATE_KEY",
  "requires": {
    "env": [
      "EVM_PRIVATE_KEY"
    ],
    "pip": [
      "x402[httpx,evm]"
    ]
  },
  "envVars": [
    {
      "name": "EVM_PRIVATE_KEY",
      "required": true,
      "description": "EVM private key for signing x402 payments on Base. Required for this skill."
    },
    {
      "name": "WALLET_PRIVATE_KEY",
      "required": false,
      "description": "Fallback alias for EVM_PRIVATE_KEY (the skill reads either)."
    }
  ],
  "cron": null,
  "autostart": false
}

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