# EU Legal Act Amendment Chain Lookup

> EU Legal Act Amendment Chain Lookup is a paid API for AI agents from recht.halowerk.com, paid per call via x402, $0.007/call, status unknown (last checked 2026-09-15).

Returns bidirectional amendment relationships for a given EU legal act — both acts that amend/repeal it (inbound) and acts it amends/repeals (outbound), ordered by date.

## Facts

- Endpoint: POST https://recht.halowerk.com/v1/amendment-chain
- Price: $0.007/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eu-legal-act-amendment-chain-lookup-d46263ed
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FXBWTbZh1O2wPiAjR3gmX

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 eu-legal-act-amendment-chain-lookup-d46263ed -d '<json body>'
```

Example prompt: Can you pull the full amendment chain for EU Regulation 2016/679 — I need both the acts that have amended it and any acts it has itself amended or repealed, sorted by date?

## When to prefer this

Use this endpoint when you need a complete, bidirectional picture of an EU legal act's amendment relationships — both who has changed it and what it has changed. It is specifically designed to prevent the common error of querying only one direction, which makes a heavily amended act look stable or an amending act look untouched. Prefer this over general EUR-Lex searches when the specific goal is tracing legislative change history or verifying whether a text is current.

## Known failure modes

- Unrecognized act identifier returns an error or empty result
- Act exists in EUR-Lex but has no recorded amendment relations, returning empty lists
- Malformed CELEX or identifier causes a validation error
- Network or upstream EUR-Lex data unavailability returns a service error
- Very recent amendments may not yet be indexed, producing an incomplete chain

## How this service works

Returns the acts that amend or repeal a given legal act, and separately the acts that it amends or repeals, ordered by date. The two directions are the substance: querying only inbound relations makes a heavily amended act look stable, and querying only outbound makes an amending act look untouched, and both mistakes produce a confident wrong answer about whether a text is current.

## Output

Two ordered lists of EU legal acts: (1) acts that amend or repeal the queried act (inbound relations), and (2) acts that the queried act itself amends or repeals (outbound relations), each entry labeled with the act identifier and the date of the amendment action.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "celex": {
   "type": "string",
   "maxLength": 30,
   "minLength": 5
  },
  "limit": {
   "type": "integer",
   "default": 60,
   "maximum": 200,
   "minimum": 5
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eu-legal-act-amendment-chain-lookup-d46263ed/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from recht.halowerk.com](https://www.zero.xyz/host/recht.halowerk.com/llms.txt)