# HTS Pilot API

> HTS Pilot proposes tariff codes from a product description for three import markets (United States, European Union, Vietnam), with the reasons, the sources and a review queue. This is the documentation of its HTTP API: single lookups, batch files, a SKU catalog, tariff data and duty estimates, usage, review decisions and signed webhooks.

Base URL: https://htspilot.com/api. Send an API key in the `X-API-Key` header of every request; keys are created in the application under Admin, API keys. Every page below is Markdown; the same address without `.md` is the page for people. The whole documentation in one file: https://docs.htspilot.com/llms-full.txt

## Guides

- [Introduction](https://docs.htspilot.com/index.md): What the HTS Pilot API does, its base URL, a first request that works, and how these pages are organised.
- [Authentication](https://docs.htspilot.com/authentication.md): API keys for the HTS Pilot API - where to create one, how to send it, what a role allows, and what 401 and 403 answers look like.
- [Errors](https://docs.htspilot.com/errors.md): The error body of the HTS Pilot API with its machine-readable code, the status codes in use, validation errors, plan refusals and how messages follow Accept-Language.
- [Request identifiers](https://docs.htspilot.com/request-identifiers.md): Every answer of the HTS Pilot API carries an identifier in X-Request-ID - what it is, how to send a reference of your own, and what to quote when asking for help.
- [Rate limits and quotas](https://docs.htspilot.com/rate-limits.md): What limits the use of the HTS Pilot API - credits, the limits of a plan, the few per-minute limits, and the size limits of a request.
- [Pagination](https://docs.htspilot.com/pagination.md): How lists are paged in the HTS Pilot API - page and page_size on the paged lists, limit and offset on the others, and the shape of each answer.
- [Languages](https://docs.htspilot.com/languages.md): The two language settings of the HTS Pilot API - Accept-Language for labels and messages, and the answer language of a lookup, set with the language field of a classify request.
- [Versioning and changes](https://docs.htspilot.com/versioning.md): How the HTS Pilot API changes - one live version for everyone, dated records of the published contract, what counts as a breaking change and how a client keeps working.
- [Asynchronous work](https://docs.htspilot.com/asynchronous-work.md): Lookups and batches run in the background - the 202 answer, the states of a lookup and of a batch, how to poll, and webhooks as the alternative.
- [Webhooks](https://docs.htspilot.com/webhooks.md): Signed notifications from HTS Pilot to your system - creating a webhook, the events and their payloads, verifying the signature, retries and which URLs are accepted.
- [Build with AI agents](https://docs.htspilot.com/ai-agents.md): What these pages offer to AI agents and coding assistants - every page as Markdown, llms.txt, the OpenAPI document, and ready-made skills that teach an agent to integrate the HTS Pilot API.

## API reference

- [Lookups](https://docs.htspilot.com/lookups.md): Classify one product and read the result - the lookup object, the recommended code, the other candidates, the reasons, the sources and what is still missing.
- [Review](https://docs.htspilot.com/review.md): The queue of lookups that need a person, and the reviewer's decision on a lookup - approve, override, reject, reopen or comment.
- [Batches](https://docs.htspilot.com/batches.md): Classify a file of products - upload an .xlsx or .csv file, choose the columns, start it, follow its progress and download the results.
- [Catalog](https://docs.htspilot.com/catalog.md): The shared SKU catalog - keep it in step with an ERP or PIM, check the codes in use against the active tariff schedule, and read the alerts raised when a schedule changes.
- [Tariff data](https://docs.htspilot.com/tariff-data.md): The loaded tariff schedules - search and browse codes, changes between versions, duty and landed cost estimates, compliance hints and CBP rulings.
- [Usage](https://docs.htspilot.com/usage.md): The credit balance of the account, what was spent, the credit ledger, and what the plan of the account allows.
- [Webhook endpoints](https://docs.htspilot.com/webhook-endpoints.md): Register, change, test and delete webhooks through the API, and read the deliveries of a webhook.
- [Reports](https://docs.htspilot.com/reports.md): Review productivity and quality for a period - lookups, decisions and decision times.
- [System](https://docs.htspilot.com/system.md): Whether the HTS Pilot service is up, and which account and role an API key belongs to.

## Optional

- [OpenAPI specification](https://docs.htspilot.com/openapi.json): every operation with its parameters and schemas, as JSON
- [Changelog](https://docs.htspilot.com/changelog.md): dated versions of the API and what changed in each; earlier versions of the reference are linked from it
- [Agent skill](https://docs.htspilot.com/skill.md): how a coding agent should use this API and these pages, in one file
- [Skill hts-pilot-api](https://docs.htspilot.com/skills/hts-pilot-api/SKILL.md): Integrate the HTS Pilot API (tariff classification for the US, EU and Vietnam import markets) into a system (folder: https://docs.htspilot.com/skills/hts-pilot-api.zip)
- [Skill hts-pilot-webhooks](https://docs.htspilot.com/skills/hts-pilot-webhooks/SKILL.md): Receive HTS Pilot webhooks in a system (folder: https://docs.htspilot.com/skills/hts-pilot-webhooks.zip)
- [Skill hts-pilot-batch](https://docs.htspilot.com/skills/hts-pilot-batch/SKILL.md): Classify a file of products with the HTS Pilot API (folder: https://docs.htspilot.com/skills/hts-pilot-batch.zip)
- [Index of the agent skills](https://docs.htspilot.com/skills/index.json): every skill with its files and where to download it
- [API explorer](https://docs.htspilot.com/explorer/): sends requests to the live API from a browser, with your key
- [HTS Pilot](https://htspilot.com/llms.txt): the product site and its articles