eBay Agent

eBay research agent. Search for deals, evaluate prices, and get fair value estimates using eBay REST APIs. No eBay account required — just a free developer API key.

ebay-agent — eBay Research Agent

Search eBay for deals, estimate item values, and rank results by price, seller trust, and condition — all via eBay's official REST APIs.

Trigger Phrases

• "Search eBay for [item]"
• "Find me a used [item] on eBay"
• "What's [item] worth on eBay?"
• "How much is [item] selling for?"
• "Is this a good deal on eBay?"

Commands

All commands are run via uv run --project <skill_dir> ebay-agent <command>.

search — Find items on eBay

ebay-agent search "Sony 85mm f/1.8 lens"
ebay-agent search "iPad Air" --max-price 300 --condition used
ebay-agent search "Nintendo Switch" --sort price --limit 20

Options: --max-price/-p, --condition/-c (new, used, very_good, good, acceptable), --limit/-n (default: 10), --sort/-s (score, price, seller), --json

value — Estimate what an item is worth

ebay-agent value "iPad Air 2 64GB"
ebay-agent value "Sony 85mm f/1.8 lens" --condition very_good --limit 30

Returns fair range, median, confidence level, listing count, and a recommended price based on current market data. Tries eBay Marketplace Insights (sold data) first, falls back to Browse API (active listings). Outliers are trimmed automatically.

Options: --condition/-c (default: used), --limit/-n (default: 20), --json

deal — Evaluate if an item is a good deal

ebay-agent deal "Sony FE 85mm f/1.8"
ebay-agent deal "MacBook Pro M3" --condition used
ebay-agent deal "Nintendo Switch OLED" --price 280

Fetches comparable listings, filters out accessories and irrelevant results, computes a fair value range, and tells you whether to buy. With --price, rates a specific price as great deal / good deal / fair / overpriced.

Options: --condition/-c (default: used), --price/-p (evaluate a specific price), --limit/-n (default: 25), --json

watch — Save searches and check for deals

# Add a watch (--max-price is required)
ebay-agent watch add "Sony FE 85mm f/1.8" --max-price 300 --condition used

# List active watches
ebay-agent watch list

# Remove a watch by ID
ebay-agent watch remove sony-fe-85-a1b2

# Check all watches against live eBay data
ebay-agent watch check

Watches are stored in ~/.ebay-agent/watches.json. Override with --state-file <path> on any watch subcommand.

watch check searches eBay for each saved query, filters for relevance, and reports any listing at or below your max price. No built-in scheduler — run watch check manually or via cron.

Options: --max-price/-p (required on add), --condition/-c (default: used), --state-file

prefs — View search preferences

ebay-agent prefs

Shows current scoring preferences: min condition, min seller score, budget, strategy (price/speed/balanced).

Required Environment Variables

Variable	Required	Description
EBAY_APP_ID	Yes	eBay app client ID from developer.ebay.com
EBAY_CERT_ID	Yes	eBay app client secret from developer.ebay.com
EBAY_ENVIRONMENT	No	sandbox or production (default: production)

How to get eBay credentials

1. Go to developer.ebay.com and create a free account
2. Create an application to get your App ID and Cert ID
3. Set EBAY_APP_ID and EBAY_CERT_ID in your environment

Example workflow

# Search for deals (accessories auto-filtered)
ebay-agent search "Sony 85mm f/1.8 lens" --max-price 400 --condition used

# Check fair market value with confidence
ebay-agent value "Sony 85mm f/1.8 lens"

# Evaluate a deal — is this price good?
ebay-agent deal "Sony FE 85mm f/1.8" --price 320

# Quick deal check without a specific price
ebay-agent deal "MacBook Pro M3"

# View preferences
ebay-agent prefs