# ToolSchema Forge - OpenAPI to LLM Tool Schema Converter

> ToolSchema Forge - OpenAPI to LLM Tool Schema Converter is a paid API for AI agents from toolschema-forge.toolschemaforge.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Converts an OpenAPI 3.x or Swagger 2.0 spec into LLM-ready tool schemas for OpenAI, Anthropic, Gemini, or MCP, with linting and issue reporting.

## Facts

- Endpoint: POST https://toolschema-forge.toolschemaforge.workers.dev/v1/openapi/to-tools?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/toolschema-forge-openapi-to-llm-tool-schema-converter-9ad96496
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sKP9znY8PSzV_ROlGEdnk

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 toolschema-forge-openapi-to-llm-tool-schema-converter-9ad96496 -d '<json body>'
```

Example prompt: Convert my OpenAPI 3.0 spec to Anthropic tool schemas — here's the spec as JSON — and flag any linting issues that might break Claude's tool calling.

## When to prefer this

Choose this endpoint when you need deterministic, provider-specific LLM tool schemas — especially when targeting multiple providers (OpenAI strict, Anthropic, Gemini, MCP) from a single OpenAPI/Swagger source of truth, and when you want lint feedback on schema compatibility issues. Prefer it over manual schema writing or generic JSON converters when you need LLM-provider-aware validation and auto-fixing.

## Known failure modes

- Invalid or malformed OpenAPI/Swagger JSON causes parsing errors
- Unsupported spec version results in conversion failure
- maxTools limit truncates output without error if spec exceeds threshold
- Operations with unsupported parameter types are skipped and listed in skipped array
- Payment failure via x402 returns 402 before processing
- Missing required 'spec' field causes validation error
- Spec with no convertible operations returns empty tools array

## How this service works

Deterministic LLM tool-schema conversion, linting and MCP manifest generation for OpenAI (incl. strict mode), Anthropic, Gemini and MCP, paid per call in USDC on Base via x402.

## Output

A JSON object with: count (number of tools generated), tools (array of LLM-format tool schema objects ready to pass to the target provider), issues (array of lint findings with provider, path, code, message, severity, and whether auto-fixed), and skipped (array of operations that couldn't be converted with reasons).

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "spec"
     ],
     "properties": {
      "spec": {
       "type": "object",
       "description": "OpenAPI 3.x or Swagger 2.0 document as JSON."
      },
      "target": {
       "enum": [
        "openai",
        "openai_strict",
        "anthropic",
        "gemini",
        "mcp",
        "jsonschema"
       ],
       "type": "string",
       "description": "Output format. Default openai."
      },
      "include": {
       "type": "array",
       "items": {
        "type": "string"
       },
       "description": "Optional operationIds or 'METHOD /path' strings to include."
      },
      "maxTools": {
       "type": "integer",
       "maximum": 128,
       "minimum": 1
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "count",
      "tools",
      "skipped",
      "issues"
     ],
     "properties": {
      "count": {
       "type": "integer"
      },
      "tools": {
       "type": "array",
       "items": {
        "type": "object"
       }
      },
      "issues": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "provider",
         "path",
         "code",
         "message",
         "severity",
         "fixed"
        ],
        "properties": {
         "code": {
          "type": "string"
         },
         "path": {
          "type": "string"
         },
         "fixed": {
          "type": "boolean"
         },
         "message": {
          "type": "string"
         },
         "provider": {
          "enum": [
           "openai",
           "openai_strict",
           "anthropic",
           "gemini",
           "mcp",
           "jsonschema"
          ],
          "type": "string"
         },
         "se
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 1,
  "tools": [
   {
    "name": "getPet",
    "description": "Get a pet by id",
    "input_schema": {
     "type": "object",
     "required": [
      "id"
     ],
     "properties": {
      "id": {
       "type": "string"
      }
     }
    }
   }
  ],
  "issues": [],
  "skipped": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/toolschema-forge-openapi-to-llm-tool-schema-converter-9ad96496/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toolschema-forge.toolschemaforge.workers.dev](https://www.zero.xyz/host/toolschema-forge.toolschemaforge.workers.dev/llms.txt)