NEXUS Grammar Fix

Fix grammar, spelling, and improve writing

Security Scan

The skill is internally coherent: it simply forwards text to a paid NEXUS grammar-fix API and requires a payment-proof credential; nothing in the files suggests hidden behavior, but you will be sending a credential to an external service so exercise normal caution.

Purpose & Capability

Name/description (grammar/spelling fixer) align with the SKILL.md and README: the skill calls an external NEXUS grammar-fix API and charges per request. Requiring a payment proof credential (NEXUS_PAYMENT_PROOF) is consistent with a paid external service.

Instruction Scope

Instructions are narrowly scoped to calling the external API (https://ai-service-hub-15.emergent.host) with payment headers. They do not request filesystem or shell access. However the runtime instructions explicitly tell the agent to include a payment proof header (which the skill declares as an env var) — that means a secret-like value will be transmitted to the external host as part of normal operation.

Install Mechanism

This is an instruction-only skill with no install spec or code to download, so nothing is written to disk by an installer. Lower risk from install mechanism.

Credentials

Only one required env var (NEXUS_PAYMENT_PROOF) is declared and is used to authorize payment. That is proportionate to a paid external API. It is nevertheless sensitive: the skill will send that value to the external service, so provide a least-privileged/payment-specific credential (or use sandbox_test for trials).

Persistence & Privilege

The skill does not request persistent/always-on privileges, does not modify other skills, and does not ask to write agent config. Default autonomous invocation is enabled (normal), but always:false limits forced inclusion.

Assessment

This skill is coherent with its stated purpose: it forwards text to a paid NEXUS grammar service and expects a payment-proof header. Before installing, verify you trust the endpoint (https://ai-service-hub-15.emergent.host) and the service terms. Use sandbox_test for trial runs instead of placing a real payment credential in NEXUS_PAYMENT_PROOF. If you must supply a real credential, use a payment-specific, revocable token (not a long-lived wallet private key) and be prepared to rotate/revoke it. If you need higher assurance, ask the publisher for formal documentation of the payment protocol, and validate the endpoints out-of-band. Confidence is medium because this is instruction-only (no code to audit) and the external host is not a widely-known vendor; access to the real service documentation or publisher identity would raise confidence.

Grammar Fixer

NEXUS Agent-as-a-Service on Cardano + Stellar | Price: $0.02/request | Accepts: ADA, DJED, iUSD, USDCx, USDM (Cardano) + USDC, XLM (Stellar)

When to use

Use when you need to fix grammar, spelling, and improve writing.

Steps

Option A: x402 Standard (Recommended)

1. Call the service endpoint without payment headers.
2. Receive HTTP 402 with WWW-Authenticate: Payment header AND x402 accepts[] array in response body.
3. Select a paymentRequirement from accepts[] matching your preferred network + asset.
4. Networks: cardano:mainnet (ADA, DJED, iUSD, USDCx, USDM), stellar:pubnet (USDC, XLM), sandbox (free).
5. Send payment to the payTo address for maxAmountRequired in the specified asset.
6. Stellar fee sponsorship: POST your signed XDR to https://ai-service-hub-15.emergent.host/api/mpp/stellar/sponsor — NEXUS pays gas, you need 0 XLM.
7. Retry with X-PAYMENT: <base64url JSON {x402Version:1, scheme:"exact", network, payload:{tx_hash, currency}}> header.
8. Parse the JSON response and X-PAYMENT-RESPONSE header.

Option B: MPP Standard

1. Call the service endpoint without payment headers.
2. Receive HTTP 402 with WWW-Authenticate: Payment header listing all accepted currencies and amounts.
3. Pick your preferred chain + currency: Cardano (ADA, stablecoins) or Stellar (USDC, XLM).
4. Create payment: Masumi escrow (Cardano) or direct Stellar transfer.
5. Stellar fee sponsorship: POST your signed XDR to https://ai-service-hub-15.emergent.host/api/mpp/stellar/sponsor — NEXUS pays gas, you need 0 XLM.
6. Retry with Authorization: Payment <base64url-credential> header.
7. Parse the JSON response and Payment-Receipt header.

Option C: Legacy Header

1. Send a POST request to the NEXUS API endpoint with your input.
2. Include the X-Payment-Proof header (Masumi payment ID or sandbox_test for testing).
3. Parse the JSON response and return the result.

API Call

curl -X POST https://ai-service-hub-15.emergent.host/api/original-services/grammar-fix \
  -H "Content-Type: application/json" \
  -H "X-Payment-Proof: $NEXUS_PAYMENT_PROOF" \
  -d '{
  "input": "Example input for Grammar Fixer"
}'

Endpoint: https://ai-service-hub-15.emergent.host/api/original-services/grammar-fix Method: POST Headers:

• Content-Type: application/json
• X-PAYMENT: <base64url JSON> (x402 standard — recommended)
• Authorization: Payment <credential> (MPP standard)
• X-Payment-Proof: <masumi_payment_id> (legacy — use sandbox_test for free testing)

Accepted Currencies: ADA, DJED, iUSD, USDCx, USDM (Cardano) | USDC, XLM (Stellar) x402 Discovery: GET https://ai-service-hub-15.emergent.host/api/mpp/x402 (all services in native x402 format) MPP Discovery: GET https://ai-service-hub-15.emergent.host/api/mpp/discover Stablecoin Registry: GET https://ai-service-hub-15.emergent.host/api/mpp/stablecoins (includes on-chain policy IDs) Stellar Info: GET https://ai-service-hub-15.emergent.host/api/mpp/stellar (assets, recipient, fee sponsorship) Fee Sponsorship: POST https://ai-service-hub-15.emergent.host/api/mpp/stellar/sponsor (NEXUS pays Stellar gas — agents need 0 XLM)

External Endpoints

URL	Method	Data Sent
https://ai-service-hub-15.emergent.host/api/original-services/grammar-fix	POST	Input parameters as JSON body

Security & Privacy

• All data is sent to https://ai-service-hub-15.emergent.host over HTTPS/TLS.
• No data is stored permanently; requests are processed and discarded.
• Payment proofs are verified on the Cardano blockchain via the Masumi Protocol.
• No filesystem access or shell execution required.

Model Invocation Note

This skill calls the NEXUS AI service API which uses LLM models (GPT-5.2, Claude Sonnet 4.5, GPT-4o) to process requests. The AI processes your input server-side and returns a structured response. You may opt out by not installing this skill.

Trust Statement

By using this skill, your input data is sent to NEXUS (https://ai-service-hub-15.emergent.host) for AI processing. Payments are non-custodial via the Masumi Protocol on Cardano. Only install if you trust NEXUS as a service provider. Visit https://ai-service-hub-15.emergent.host for full documentation.

Tags

machine-learning, artificial-intelligence, free-trial, agent-to-agent, health-monitoring, budget