# Citation Formatter — DOI to BibTeX/APA/MLA

> Citation Formatter — DOI to BibTeX/APA/MLA is a paid API for AI agents from the-stall.intuitek.ai, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Converts a DOI into a formatted academic citation in BibTeX, APA, MLA, or all formats at once

## Facts

- Endpoint: GET https://the-stall.intuitek.ai/cap/citation-formatter
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/citation-formatter-doi-to-bibtex-apa-mla-1c6f1418
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_U99XvADoxr52s050XV8BW

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 citation-formatter-doi-to-bibtex-apa-mla-1c6f1418
```

Example prompt: Can you give me the BibTeX citation for the paper with DOI 10.1038/nature12345?

## When to prefer this

Use this endpoint when you need to programmatically generate academic citations from DOIs without API keys or account setup, especially in research automation pipelines, bibliography generators, or AI agents helping users write papers. Prefer this over manual lookup when you already have a DOI and need a specific citation format instantly.

## Known failure modes

- Invalid or malformed DOI returns an error — DOI must follow standard format like '10.xxxx/...'
- DOI not found in upstream metadata sources returns a 404-style error
- Unsupported format enum value returns a validation error
- Network timeout if upstream DOI resolver is slow

## How this service works

Domain-agnostic x402 capability chassis by IntuiTek¹. 210 AI-callable data services — pay USDC on Base mainnet. No accounts or API keys required.

## Output

A formatted citation string in the requested style (BibTeX, APA, MLA) for the paper identified by the given DOI, or all three formats if 'all' is specified.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "doi": "10.1038/nature12345",
   "format": "bibtex"
  }
 }
}
```

## 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": [],
     "properties": {
      "doi": {
       "type": "string",
       "description": "Digital Object Identifier (e.g. '10.1038/nature12345' or 'https://doi.org/10.1038/nature12345')."
      },
      "format": {
       "enum": [
        "bibtex",
        "apa",
        "mla",
        "all"
       ],
       "type": "string",
       "description": "Citation format. 'all' returns every format. Default: 'bibtex'."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/citation-formatter-doi-to-bibtex-apa-mla-1c6f1418/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from the-stall.intuitek.ai](https://www.zero.xyz/host/the-stall.intuitek.ai/llms.txt)