walmart-mcp: Instructions file for Claude Code

CLAUDE.md

walmart-mcp CLAUDE.md is an instructions file for Claude Code from luke-nielsen/walmart-mcp. It costs 1,063 tokens per session, scanned A, original, MIT.

Repository-specific instructions for Claude Code when working on a TypeScript MCP server that provides a reusable Walmart API client. It covers Walmart seller and consumer APIs, their separate authentication methods, architecture, and development rules.

In plain words
What is it for?
Use them when changing Walmart product searches, catalog data, reviews, store locations, seller items, inventory, prices, orders, authentication, or MCP tools.
Why use it?
They prevent agents from mixing two different Walmart APIs or their authentication methods and document the checks needed for safe changes.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code.

This is luke-nielsen/walmart-mcp's own configuration. It tells Claude Code how to work on walmart-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything walmart-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to luke-nielsen/walmart-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/luke-nielsen/walmart-mcp/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/luke-nielsen/walmart-mcp

Made for: Claude Code.

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Per session 1,063 This file is loaded in full into every session.
When invoked 1,063 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.01063 $0.01063
Opus 5 $0.00531 $0.00531
Sonnet 5 $0.00213 $0.00213
Haiku 4.5 $0.00106 $0.00106

Measured 9d ago against content hash 86985249fe0a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

walmart-mcp CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 87 lines

How it starts

The opening of the file, as written. The whole thing — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

Guidance for Claude Code working in this repo.

What this is

A from-scratch TypeScript Walmart API client, delivered as an MCP server (stdio) with a reusable SDK underneath. It wraps two distinct Walmart APIs behind one client:

  • Marketplace (seller) — https://marketplace.walmartapis.com, OAuth 2.0. Items, inventory, prices, orders.
  • Affiliate / Catalog (consumer) — https://developer.api.walmart.com/..., RSA signature auth. Product search, lookup, taxonomy, trending, reviews, store locator (read-only).

Either surface can be configured independently; tools register only for configured surfaces.

The locked implementation spec is tech.md — consult it before changing auth, the HTTP client, or the tool surface. README.md covers setup.

Hard constraints (the two APIs genuinely differ — do not unify them)

  • Two auth schemes, not one. Marketplace uses an OAuth bearer token (WM_SEC.ACCESS_TOKEN) that expires (~15 min) and is cached + refreshed. Affiliate signs every request with the RSA private key (WM_SEC.AUTH_SIGNATURE) — no token, nothing to cache. Don't try to route affiliate through the token path or vice versa.
  • Two base URLs. The client picks the base URL from the request's surface.
  • Affiliate is read-only. It has no cart/checkout/write. Writes live on Marketplace (inventory, price, order acknowledge).
  • Affiliate access is gated. Credentials require Walmart.io affiliate-program approval; Marketplace requires a Seller/Solution-Provider account. The code degrades gracefully when a surface is unconfigured (its tools simply aren't registered).

Commands

npm run build       # tsc → dist/ (required before running the MCP server)
npm test            # vitest, fetch mocked — no credentials needed
npm run typecheck   # tsc --noEmit
npm run check       # validate whichever surfaces are configured (loads .env)
npm start           # run the MCP server standalone (loads .env via --env-file)

Read the full file on GitHub · 87 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 87 lines · 1,063 tokens per session scan A 86985249fe0a

Subscribe to this mod's changes

walmart-mcp CLAUDE.md is an instructions file published in the GitHub repository luke-nielsen/walmart-mcp (0 stars, last pushed 2mo ago), licensed MIT. It adds 1,063 tokens to every session, about $0.0053 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.

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