# Delx OpenAPI Breaking Change

> Delx OpenAPI Breaking Change is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Detects removed paths and methods between two OpenAPI specifications to identify client-breaking changes before deployment

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/openapi-breaking-change
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-openapi-breaking-change-2a46fb33
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ogeP_xl2GjyUg06pGLYOU

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 delx-openapi-breaking-change-2a46fb33 -d '<json body>'
```

Example prompt: Before I deploy this new API spec, check whether it removes any paths or HTTP methods from the old version — here's the old spec and the new candidate spec, and flag any breaking changes.

## When to prefer this

Choose this endpoint when you need a deterministic, stateless, first-party check for removed OpenAPI paths and methods before deploying an API update, executing an automated workflow that depends on a stable API contract, or evaluating whether an untrusted spec change is safe to apply. It is purpose-built for breaking-change detection rather than general OpenAPI linting or full semantic diffing.

## Known failure modes

- Malformed or invalid JSON in old_spec or new_spec returns a structured validation error without billing
- Missing required fields (old_spec or new_spec) returns a validation failure
- Extremely large OpenAPI documents may hit payload size limits
- Non-OpenAPI JSON objects passed as specs may produce empty or misleading diffs

## How this service works

Detect removed OpenAPI paths and methods before an agent deploys a client-breaking change. Use it before an autonomous workflow acts on untrusted input, changes an API, retries a request, or evaluates production reliability. Returns bounded machine-readable JSON for $0.002 USDC via x402 on Base. Execution is deterministic, first-party, local-only, stateless, and does not call an upstream provider; structured validation failures are not billed.

## Output

Returns a bounded machine-readable JSON object listing any OpenAPI paths and HTTP methods present in the old spec but missing from the new spec, indicating which changes constitute client-breaking removals. Structured validation failures (e.g. malformed input) are returned without billing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "new_spec": {
   "type": "object",
   "description": "Candidate OpenAPI JSON document."
  },
  "old_spec": {
   "type": "object",
   "description": "Previous OpenAPI JSON document."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "scope": "removed paths and methods; semantic schema compatibility requires a deeper review",
  "schema": "delx/openapi-breaking-change/v1",
  "breaking": true,
  "new_version": "",
  "old_version": "",
  "removed_count": 1,
  "removed_operations": [
   "/jobs"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-openapi-breaking-change-2a46fb33/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)