# DOI Citation Formatter

> DOI Citation Formatter is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Formats a DOI into a styled bibliography citation string in APA, MLA, Chicago, IEEE, Harvard, or Vancouver style

## Facts

- Endpoint: GET https://api.x402node.dev/citation/format
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-x402node-dev-97daa60e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_miTi_1mBlyp0lBOMYjR9v

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-x402node-dev-97daa60e
```

Example prompt: Can you format the paper with DOI 10.1038/nature12373 as a proper APA citation for my bibliography?

## When to prefer this

Use this endpoint when an AI agent needs to produce a formatted citation from a DOI for any of the six major citation styles. It is purpose-built for agents generating draft references and academic documents, avoiding the need to parse DOI metadata manually and apply citation formatting rules.

## Known failure modes

- DOI not found or invalid — returns error indicating the DOI could not be resolved
- Unsupported citation style specified — returns error with valid style options
- DOI metadata incomplete — citation may be partially formatted or missing fields
- Network timeout resolving DOI metadata from upstream resolver

## How this service works

Format any DOI into a styled citation (apa, mla, chicago, ieee, harvard, vancouver). Returns plain-text bibliography string. Use ?doi=10.1038/nature12373 and style=apa. Built for AI agents producing draft references. Accepts payment on Base or Solana — either network works.

## Output

A plain-text bibliography string with the citation formatted in the requested style (APA, MLA, Chicago, IEEE, Harvard, or Vancouver), ready to paste into a reference list or document.

## Example request

```json
{
 "doi": "10.1038/nature12373",
 "style": "APA"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "doi"
     ],
     "properties": {
      "doi": {
       "type": "string",
       "description": "DOI string (required)"
      },
      "style": {
       "type": "string",
       "description": "Style (optional)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-x402node-dev-97daa60e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)