Agents & AI - CarsXE Docs

CarsXE is built to be agent-friendly. Whether you are a coding agent onboarding a new project, an LLM reasoning about vehicle data, or an automation pipeline calling REST endpoints, this page covers the features we ship specifically for AI and agent use cases.

Browser-based agent onboarding

Getting a CarsXE API key from inside any AI agent — Claude Code, Claude Desktop, Cursor, Codex CLI, Gemini CLI, or any other coding assistant — takes just a few steps with no CLI install required. The agent directs you to a browser page, waits for you to authorize, then retrieves and stores your key automatically.

The complete machine-readable skill document for agents is available at https://carsxe.com/agent-onboarding/SKILL.md. Agents that support skill discovery (such as Claude Code) will pick this up automatically.

Step 1 — Give your agent the onboarding skill

Pass the skill document URL to your agent so it knows exactly how to authenticate:

"Use this skill to get a CarsXE API key: https://carsxe.com/agent-onboarding/SKILL.md"

The agent fetches the skill, generates secure session parameters, then presents you with a clickable link to open in your browser.

Step 2 — Authorize in the browser

Click the link the agent provides. You will be taken to the CarsXE authorization page where you can sign in or create an account and approve access. No typing required — just click Authorize.

Step 3 — Your agent retrieves the key

Once you click Authorize, the agent polls in the background and retrieves your API key. It stores it automatically (typically as CARSXE_API_KEY in your environment or project .env file).

Step 4 — Start making calls

Your agent can immediately start making vehicle data calls on your behalf:

"Decode VIN WBAFR7C57CC811956" "What is the market value of this vehicle with 50,000 miles?" "Check for any open recalls."

Machine-readable documentation

Official docs live at https://docs.carsxe.com. Prefer markdown routes, llms.txt, MCP, and the agent discovery spec over scraping HTML.

Bootstrap from the discovery spec

Before implementing from these docs, fetch the agent discovery document:

Terminal

curl https://docs.carsxe.com/.well-known/agent.json
# fallbacks:
curl https://docs.carsxe.com/.well-known/agent
curl https://docs.carsxe.com/api/docs?agent=spec

Use that JSON for the docs entry path, markdown route pattern, search endpoint, MCP endpoint, llms.txt routes, sitemap routes, AGENTS.md, skill.md, and feedback endpoints.

Markdown routes (`.md`)

Append .md to any docs page URL for clean Markdown — fewer tokens, no layout markup:

Terminal

curl https://docs.carsxe.com/docs/get-started.md
curl https://docs.carsxe.com/docs/products/specifications.md
curl https://docs.carsxe.com/docs/guides/agents.md

Successful markdown responses include Link: <canonical-page-url>; rel="canonical" so agents can cite the normal HTML docs URL.

Content negotiation (`Accept: text/markdown`)

Send Accept: text/markdown (or Signature-Agent) on the canonical page URL to receive the same Markdown without appending .md:

Terminal

curl -H "Accept: text/markdown" https://docs.carsxe.com/docs/get-started
curl -H "Signature-Agent: https://chatgpt.com" https://docs.carsxe.com/docs/get-started

Type	Description
`text/html`	Default browser response
`text/markdown`	Clean Markdown — no layout, no navigation chrome

Responses vary by Accept / Signature-Agent so caches keep HTML and Markdown separate.

Docs MCP

Search and read these docs over Streamable HTTP MCP:

https://docs.carsxe.com/mcp
https://docs.carsxe.com/.well-known/mcp

(This is the docs MCP server for retrieving documentation. The CarsXE API MCP for vehicle data tools is separate — see MCP Server.)

Site index for LLMs (`llms.txt`)

CarsXE Docs exposes a machine-readable index at https://docs.carsxe.com/llms.txt (full corpus: /llms-full.txt). Page markdown also includes an LLM index: /llms.txt directive near the top.

Terminal

curl https://docs.carsxe.com/llms.txt
curl https://docs.carsxe.com/llms-full.txt

The marketing/API site at https://carsxe.com/llms.txt remains available with live pricing context for the product homepage.

Making API calls from an agent

All endpoints accept key=YOUR_API_KEY as a query parameter — the same environment variable the onboarding flow stores. POST endpoints also send the body as JSON with Content-Type: application/json.

Vehicle Specifications (VIN Decode)

Decode a VIN and retrieve full vehicle specifications: make, model, year, engine, trim, equipment, and more. See full reference.

Request

curl -G https://api.carsxe.com/specs \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Market Value

Estimate retail, trade-in, and auction values for a vehicle by VIN, with optional mileage, state, and condition adjustments. See full reference.

Request

curl -G https://api.carsxe.com/v2/marketvalue \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956 \
  -d mileage=50000 \
  -d state=CA \
  -d condition=clean

Vehicle History

Retrieve a comprehensive history report including title records, junk/salvage events, and insurance information for a VIN. See full reference.

Request

curl -G https://api.carsxe.com/history \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Vehicle Recalls

Check for open safety recalls associated with a VIN. See full reference.

Request

curl -G https://api.carsxe.com/v1/recalls \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Lien & Theft Check

Check whether a vehicle has active liens or has been reported stolen. See full reference.

Request

curl -G https://api.carsxe.com/v1/lien-theft \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Ownership (Enterprise)

Resolve vehicle owners, contacts, and address residents. See the Ownership product guide or Ownership by VIN.

Request

curl -G https://api.carsxe.com/v1/ownership/vin \
  -d key=YOUR_API_KEY \
  -d vin=1FT8X3BT0BEA61538

Plate Decoder

Look up a vehicle by license plate number. Supports 50+ countries. See full reference.

Request

curl -G https://api.carsxe.com/v2/platedecoder \
  -d key=YOUR_API_KEY \
  -d plate=7XER187 \
  -d country=US \
  -d state=CA

International VIN Decoder

Decode a non-US VIN from European, Asian, and other markets. See full reference.

Request

curl -G https://api.carsxe.com/v1/international-vin-decoder \
  -d key=YOUR_API_KEY \
  -d vin=WF0MXXGBWM8R43240

Vehicle Images

Retrieve vehicle photos by make, model, and year. Supports filtering by color, angle, photo type, and size. See full reference.

Request

curl -G https://api.carsxe.com/images \
  -d key=YOUR_API_KEY \
  -d make=BMW \
  -d model=5-Series \
  -d year=2012

Year / Make / Model

Look up vehicle data when you don't have a VIN — search by year, make, and model instead. See full reference.

Request

curl -G https://api.carsxe.com/v1/ymm \
  -d key=YOUR_API_KEY \
  -d year=2012 \
  -d make=BMW \
  -d model=5-Series

Plate Image Recognition

Extract and decode a license plate number from an image URL. See full reference.

Request

curl -X POST "https://api.carsxe.com/platerecognition?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"image_url": "https://imagedelivery.net/moyiiSImjJPI_EZVxNMBBw/f49aed53-d736-4370-f3f4-97418841c800/public"}'

VIN OCR

Extract a VIN from a photo of a VIN plate or dashboard sticker. See full reference.

Request

curl -X POST "https://api.carsxe.com/v1/vinocr?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"image_url": "https://user-images.githubusercontent.com/5663423/30922082-64edb4fa-a3a8-11e7-873e-3fbcdce8ea3a.png"}'

OBD Codes Decoder

Decode a diagnostic trouble code (DTC) from an OBD-II scanner — over 3,000 codes supported. See full reference.

Request

curl -G https://api.carsxe.com/obdcodesdecoder \
  -d key=YOUR_API_KEY \
  -d code=P0300

MCP server for AI tools

For interactive AI editors and chat clients (Claude Desktop, Cursor, VS Code, Windsurf), the CarsXE MCP server is the recommended integration path — it exposes all endpoints as named tools and formats responses as Markdown automatically.

See the MCP Quickstart Guide for installation instructions for each editor.

What's next?

Agent onboarding skill document — machine-readable PKCE auth flow
docs.carsxe.com/llms.txt — docs site index for LLMs
Agent discovery — machine-readable route map
Docs MCP — search and read docs via MCP
MCP Quickstart — CarsXE API MCP for Claude, Cursor, VS Code, Windsurf
Claude Code Plugin — slash commands and auto-invoked skills
CLI Quickstart — terminal tool for agent-driven shell workflows
Authentication — API key management
Quickstart — first API call walkthrough

Everything you need to use CarsXE vehicle data APIs from AI coding agents, LLMs, and automated pipelines — including browser-based onboarding, machine-readable documentation, and content negotiation.

llms.txt llms-full.txt

Browser-based agent onboarding

Step 1 — Give your agent the onboarding skill

Pass the skill document URL to your agent so it knows exactly how to authenticate:

"Use this skill to get a CarsXE API key: https://carsxe.com/agent-onboarding/SKILL.md"

The agent fetches the skill, generates secure session parameters, then presents you with a clickable link to open in your browser.

Step 2 — Authorize in the browser

Click the link the agent provides. You will be taken to the CarsXE authorization page where you can sign in or create an account and approve access. No typing required — just click Authorize.

Step 3 — Your agent retrieves the key

Once you click Authorize, the agent polls in the background and retrieves your API key. It stores it automatically (typically as CARSXE_API_KEY in your environment or project .env file).

Step 4 — Start making calls

Your agent can immediately start making vehicle data calls on your behalf:

"Decode VIN WBAFR7C57CC811956" "What is the market value of this vehicle with 50,000 miles?" "Check for any open recalls."

Machine-readable documentation

Official docs live at https://docs.carsxe.com. Prefer markdown routes, llms.txt, MCP, and the agent discovery spec over scraping HTML.

Bootstrap from the discovery spec

Before implementing from these docs, fetch the agent discovery document:

Terminal

curl https://docs.carsxe.com/.well-known/agent.json
# fallbacks:
curl https://docs.carsxe.com/.well-known/agent
curl https://docs.carsxe.com/api/docs?agent=spec

Use that JSON for the docs entry path, markdown route pattern, search endpoint, MCP endpoint, llms.txt routes, sitemap routes, AGENTS.md, skill.md, and feedback endpoints.

Markdown routes (`.md`)

Append .md to any docs page URL for clean Markdown — fewer tokens, no layout markup:

Terminal

curl https://docs.carsxe.com/docs/get-started.md
curl https://docs.carsxe.com/docs/products/specifications.md
curl https://docs.carsxe.com/docs/guides/agents.md

Successful markdown responses include Link: <canonical-page-url>; rel="canonical" so agents can cite the normal HTML docs URL.

Content negotiation (`Accept: text/markdown`)

Send Accept: text/markdown (or Signature-Agent) on the canonical page URL to receive the same Markdown without appending .md:

Terminal

curl -H "Accept: text/markdown" https://docs.carsxe.com/docs/get-started
curl -H "Signature-Agent: https://chatgpt.com" https://docs.carsxe.com/docs/get-started

Type	Description
`text/html`	Default browser response
`text/markdown`	Clean Markdown — no layout, no navigation chrome

Responses vary by Accept / Signature-Agent so caches keep HTML and Markdown separate.

Docs MCP

Search and read these docs over Streamable HTTP MCP:

https://docs.carsxe.com/mcp
https://docs.carsxe.com/.well-known/mcp

(This is the docs MCP server for retrieving documentation. The CarsXE API MCP for vehicle data tools is separate — see MCP Server.)

Site index for LLMs (`llms.txt`)

CarsXE Docs exposes a machine-readable index at https://docs.carsxe.com/llms.txt (full corpus: /llms-full.txt). Page markdown also includes an LLM index: /llms.txt directive near the top.

Terminal

curl https://docs.carsxe.com/llms.txt
curl https://docs.carsxe.com/llms-full.txt

The marketing/API site at https://carsxe.com/llms.txt remains available with live pricing context for the product homepage.

Making API calls from an agent

Vehicle Specifications (VIN Decode)

Decode a VIN and retrieve full vehicle specifications: make, model, year, engine, trim, equipment, and more. See full reference.

Request

curl -G https://api.carsxe.com/specs \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Market Value

Estimate retail, trade-in, and auction values for a vehicle by VIN, with optional mileage, state, and condition adjustments. See full reference.

Request

curl -G https://api.carsxe.com/v2/marketvalue \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956 \
  -d mileage=50000 \
  -d state=CA \
  -d condition=clean

Vehicle History

Retrieve a comprehensive history report including title records, junk/salvage events, and insurance information for a VIN. See full reference.

Request

curl -G https://api.carsxe.com/history \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Vehicle Recalls

Check for open safety recalls associated with a VIN. See full reference.

Request

curl -G https://api.carsxe.com/v1/recalls \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Lien & Theft Check

Check whether a vehicle has active liens or has been reported stolen. See full reference.

Request

curl -G https://api.carsxe.com/v1/lien-theft \
  -d key=YOUR_API_KEY \
  -d vin=WBAFR7C57CC811956

Ownership (Enterprise)

Resolve vehicle owners, contacts, and address residents. See the Ownership product guide or Ownership by VIN.

Request

curl -G https://api.carsxe.com/v1/ownership/vin \
  -d key=YOUR_API_KEY \
  -d vin=1FT8X3BT0BEA61538

Plate Decoder

Look up a vehicle by license plate number. Supports 50+ countries. See full reference.

Request

curl -G https://api.carsxe.com/v2/platedecoder \
  -d key=YOUR_API_KEY \
  -d plate=7XER187 \
  -d country=US \
  -d state=CA

International VIN Decoder

Decode a non-US VIN from European, Asian, and other markets. See full reference.

Request

curl -G https://api.carsxe.com/v1/international-vin-decoder \
  -d key=YOUR_API_KEY \
  -d vin=WF0MXXGBWM8R43240

Vehicle Images

Retrieve vehicle photos by make, model, and year. Supports filtering by color, angle, photo type, and size. See full reference.

Request

curl -G https://api.carsxe.com/images \
  -d key=YOUR_API_KEY \
  -d make=BMW \
  -d model=5-Series \
  -d year=2012

Year / Make / Model

Look up vehicle data when you don't have a VIN — search by year, make, and model instead. See full reference.

Request

curl -G https://api.carsxe.com/v1/ymm \
  -d key=YOUR_API_KEY \
  -d year=2012 \
  -d make=BMW \
  -d model=5-Series

Plate Image Recognition

Extract and decode a license plate number from an image URL. See full reference.

Request

curl -X POST "https://api.carsxe.com/platerecognition?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"image_url": "https://imagedelivery.net/moyiiSImjJPI_EZVxNMBBw/f49aed53-d736-4370-f3f4-97418841c800/public"}'

VIN OCR

Extract a VIN from a photo of a VIN plate or dashboard sticker. See full reference.

Request

curl -X POST "https://api.carsxe.com/v1/vinocr?key=YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"image_url": "https://user-images.githubusercontent.com/5663423/30922082-64edb4fa-a3a8-11e7-873e-3fbcdce8ea3a.png"}'

OBD Codes Decoder

Decode a diagnostic trouble code (DTC) from an OBD-II scanner — over 3,000 codes supported. See full reference.

Request

curl -G https://api.carsxe.com/obdcodesdecoder \
  -d key=YOUR_API_KEY \
  -d code=P0300

MCP server for AI tools

See the MCP Quickstart Guide for installation instructions for each editor.

What's next?

Agent onboarding skill document — machine-readable PKCE auth flow
docs.carsxe.com/llms.txt — docs site index for LLMs
Agent discovery — machine-readable route map
Docs MCP — search and read docs via MCP
MCP Quickstart — CarsXE API MCP for Claude, Cursor, VS Code, Windsurf
Claude Code Plugin — slash commands and auto-invoked skills
CLI Quickstart — terminal tool for agent-driven shell workflows
Authentication — API key management
Quickstart — first API call walkthrough

llms.txt llms-full.txt