canonical: https://jentic.com/apis/compsniper.com/compsniper # CompSniper Marketplace and Shipping APIs The CompSniper API returns resale price data from public marketplaces and quotes US shipping rates. It searches up to three years of eBay sold history, pulls completed sales and price history from TCGplayer, Poshmark, and Mercari, and returns sold-price summaries without the individual listing rows. A separate shipping-rates product estimates eBay shipping costs under its own quota, and an account usage endpoint reports remaining requests and purchased credits. Authentication uses a bearer API key with a cs_live_ prefix. ## For AI agents Search marketplace sold-price history across eBay, TCGplayer, Poshmark, and Mercari, return sold-price summaries, estimate US shipping rates, and track account quota through CompSniper. ## Scope Does not handle listing creation, order fulfillment, or payment processing. Use for marketplace sold-price research and US shipping-rate quotes only. ## Capabilities - Search up to three years of eBay sold history by keyword - Pull completed sales and price history from TCGplayer, Poshmark, and Mercari - Return a sold-price summary without the individual listing rows - Estimate US eBay shipping rates for an item - Submit a batch of trading-card comps and poll its results - Report account quota and purchased-credit usage ## Use cases ### Agent-Driven Resale Pricing An AI agent connected through Jentic can price a resale item without a human researching comps: it searches recent eBay sold history for the item and reads the sold-price summary, then recommends a list price grounded in what the item actually sold for. The summary endpoint returns the aggregate price figures without paging through every listing. Example prompt: Search eBay sold history for 'vintage denim jacket' and get the sold-price summary to recommend a list price ### Trading-Card Comps Card sellers price against recent completed sales, which move quickly. CompSniper returns TCGplayer completed sales and price history for a card, and a batch operation accepts many cards at once and reports progress, so an agent can comp a full inventory of cards in one run. Example prompt: Look up completed TCGplayer sales and price history for a card by keyword ### Cross-Marketplace Price Check Demand for an item differs by marketplace. CompSniper exposes Poshmark and Mercari sold listings alongside eBay, so an agent can compare realized prices across platforms and decide where an item is worth listing. Example prompt: Check Poshmark and Mercari sold listings for a product to compare resale demand across marketplaces ### Shipping Cost Estimate A resale price is only profit after shipping. CompSniper's separate shipping-rates product estimates eBay shipping costs for an item under its own quota, so an agent can fold a shipping estimate into a margin calculation before recommending a list price. Example prompt: Estimate the eBay shipping rate for a two-pound package to a US buyer ## Key endpoints | Method | Path | Description | | --- | --- | --- | | GET | `/v1/research/sold` | Search up to 3 years of eBay sold history | | GET | `/v1/scrape` | Search eBay sold or active listings | | GET | `/v1/summary` | Get sold-price intelligence without listing rows | | GET | `/v1/tcgplayer/sold` | TCGplayer completed sales and price history | | GET | `/v1/poshmark/sold` | Scrape Poshmark sold listings | | GET | `/v1/mercari` | Search Mercari sold or active listings | | POST | `/v1/shipping/rates` | Get eBay shipping-rate estimates | | GET | `/v1/account/usage` | Get account quota and purchased-credit usage | ## Key resources - **eBay Sold Data** — Search up to three years of eBay sold history and sold-price summaries - **Trading-Card Comps** — TCGplayer completed sales, price history, and batch card-comp jobs - **Other Marketplaces** — Poshmark and Mercari sold and active listing data - **Shipping and Account** — US eBay shipping-rate estimates and account quota and credit usage ## AI readiness This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use. - **Score:** 59 / 100 - **Maturity:** Foundational - **Dimensions:** - Foundational Compliance: 58 / 100 - Developer Experience & Jentic Compatibility: 67 / 100 - AI-Readiness & Agent Experience: 40 / 100 - Agent Usability: 94 / 100 - Security: 60 / 100 - AI Discoverability: 76 / 100 - **View full report:** https://jentic.com/apis/compsniper.com/compsniper/scorecard - **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/ - **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview ### Score it yourself Every API in the directory is allowlisted, so you can re-score it with no key required. - **Score your own API:** https://jentic.com/scorecard.md - **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md ```sh npx @jentic/api-scorecard-cli score ``` ## Why Jentic - **Setup:** Wiring CompSniper by hand means handling its bearer cs_live_ key, tracking two separate quotas for comps and shipping, and paging keyword searches per marketplace. Through Jentic you install once, import CompSniper from the API Directory, store the key once, and your agent calls it. - **Permission scoping:** CompSniper takes its keyword and marketplace as query parameters rather than a resource in the URL path, so rules bound which operations your agent may call, not which marketplace. Limit it to the read lookups it needs, such as eBay sold history and sold-price summaries, and leave the shipping-rate and batch operations out unless you add them. - **Credential handling:** Your CompSniper key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context. - **Discovery method:** Agents search Jentic by intent such as 'search eBay sold prices' or 'estimate a shipping rate', and Jentic returns the matching CompSniper operation with its input schema so the agent calls the right endpoint without browsing the reference docs. ## Related APIs - **eBay** — eBay's own APIs expose listing and marketplace data directly from the source platform. - **Walmart Marketplace** — Walmart Marketplace exposes catalog and pricing data for a different sales channel. - **Etsy** — Etsy's API covers listings and shop data for handmade and vintage goods. - **ShipEngine** — ShipEngine compares multi-carrier shipping rates and generates labels. ## FAQ ### What authentication does the CompSniper API use? The CompSniper API authenticates with a bearer API key sent as an Authorization header, where live keys carry a cs_live_ prefix per its OpenAPI spec. When you call it through Jentic, the key is stored once by your own Jentic One instance and injected at execution time, so it never reaches the agent's prompt or logs. ### How much eBay sold history can the CompSniper API return? The eBay sold-history search returns up to three years of completed sales for a keyword, with startDate, endDate, ebaySite, and sort parameters to narrow the window. The summary operation returns the aggregate sold-price figures for the same search without the individual listing rows. ### What are the rate limits for the CompSniper API? The OpenAPI spec does not define numeric per-second rate limits, but requests draw down an account quota and purchased credits, and the shipping-rates product uses a separate quota. Check your remaining quota with the account usage operation and see the CompSniper documentation at https://compsniper.com for plan limits. ### Can I limit what my agent is allowed to do with the CompSniper API? Yes. CompSniper takes its keyword and marketplace as query parameters rather than a resource in the URL path, so rules bound which operations the agent may call. Write a rule that allows only the sold-history and summary lookups, so the agent can research eBay prices but cannot submit shipping-rate quotes or card-comp batches that draw down a separate quota, and every call it makes is logged. ### How do I search eBay sold history with the CompSniper API through Jentic? Search Jentic with an intent like 'search eBay sold price history', and Jentic returns the sold-history operation at `/v1/research/sold` with its input schema so your agent passes a keyword and date range. To run it on your own infrastructure, install Jentic One from its GitHub repo. ### Is there a CompSniper MCP server? You don't need an MCP server to give your agent CompSniper. Jentic connects it directly from the API Directory: import the API, store your key once, and your agent calls the sold-history, summary, and shipping operations on demand.