# SpecDelta Schema Comparison

> SpecDelta Schema Comparison is a paid API for AI agents from specdelta-kl4hfo6j2q-as.a.run.app, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Detects breaking changes and permission expansions between two versions of an agent tool specification (MCP, OpenAI tool, or OpenAPI).

## Facts

- Endpoint: POST https://specdelta-kl4hfo6j2q-as.a.run.app/v1/spec/compare
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/specdelta-schema-comparison-22a508c4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fYmDmHUmSw1FjnP-N2yX0

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 specdelta-schema-comparison-22a508c4 -d '<json body>'
```

Example prompt: Compare these two versions of my OpenAI tool spec and tell me if the new one introduces any breaking changes or unexpected permission expansions — here's the old spec and the new spec.

## When to prefer this

Use this endpoint when you need to programmatically detect breaking changes or permission scope creep between two versions of an agent tool specification — especially in CI/CD pipelines, pre-deployment gates, or third-party spec audits. Prefer this over manual diffing or general-purpose schema validators when you specifically need agent-tool-aware semantic diffing (MCP, OpenAI tools, OpenAPI) with a focus on breaking changes and permission expansion rather than just syntactic differences.

## Known failure modes

- Invalid or unparseable JSON in either specification returns an error
- Specifications of unsupported formats (non-MCP, non-OpenAI, non-OpenAPI) may fail validation
- Missing required fields (old or new spec not provided) returns a 400 error
- Network timeout or service unavailability returns a 5xx error
- Payment failure via x402 protocol blocks the request

## How this service works

Detect breaking schema changes and permission expansion between two agent tool specifications.

## Output

A structured report listing detected breaking schema changes (e.g. removed fields, type mismatches, renamed operations) and permission expansions (e.g. newly requested scopes or capabilities) between the two provided specifications, along with severity indicators for each finding.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/specdelta-schema-comparison-22a508c4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from specdelta-kl4hfo6j2q-as.a.run.app](https://www.zero.xyz/host/specdelta-kl4hfo6j2q-as.a.run.app/llms.txt)