# CAIP-2 Chain Identifier Builder

> CAIP-2 Chain Identifier Builder is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Builds a CAIP-2 chain identifier string from a namespace and reference pair using local deterministic computation

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/caip2-build
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/caip-2-chain-identifier-builder-cfb43270
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Fg65-hGduoGxwq5uiqU1J

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 caip-2-chain-identifier-builder-cfb43270 -d '<json body>'
```

Example prompt: Build me a CAIP-2 chain identifier using namespace 'eip155' and reference '1' so I can use it in our multi-chain agent tooling.

## When to prefer this

Choose this endpoint when you need a fast, deterministic, offline-safe method to produce CAIP-2 chain identifiers without any RPC calls, API keys, or external dependencies. Ideal for multi-chain agent tooling that must emit standard chain IDs on the fly.

## Known failure modes

- Missing namespace or reference field results in an error response
- Malformed or empty string inputs may produce an invalid CAIP-2 identifier
- Payment failure via x402 protocol will block the response

## How this service works

Build CAIP-2 chain identifiers from namespace and reference. Call when emitting standard chain IDs for multi-chain agent tooling. Returns caip2 string as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.

## Output

Returns a deterministic JSON object containing the caip2 string (e.g. 'eip155:1') formed by combining the provided namespace and reference with a colon separator, conforming to the CAIP-2 standard.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "namespace": {
   "type": "string",
   "description": "Input field: namespace."
  },
  "reference": {
   "type": "string",
   "description": "Input field: reference."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "caip2": "eip155:8453",
  "schema": "delx/util-caip2-build/v1",
  "namespace": "eip155",
  "reference": "8453"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/caip-2-chain-identifier-builder-cfb43270/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)