WORKBENCH INDEX06 TOOLS
Small tools for
expensive mistakes.
Each workbench is narrow enough to explain its own result, and every rule it applies links to the note and primary source behind it.
How these differ
Most online API utilities ask you to send a request through them. These do the opposite: they take evidence you already have — a response transcript, a set of headers, two OpenAPI documents, a JSON Schema — and reason about it locally. No credential ever needs to leave your machine, and no remote endpoint is called on your behalf.
The trade-off is honest scope. A tool that never calls your API cannot tell you what the server would do next; it can tell you exactly what the evidence proves, what remains unknown, and which check comes next. Each result separates observed fields from recommendation.
API response and error decoder
Paste an HTTP response, error body, headers, or provider message. Separate transport, authentication, throttling, validation, and upstream failures before changing code.
- Reads
- HTTP transcript, JSON error, headers, or plain text
- Returns
- Layered verdict, evidence, redaction warnings, and next checks
CORS preflight request simulator
Model a browser preflight without calling a remote server. Compare the requested origin, method, headers, and credentials against the response policy.
- Reads
- Origin, method, request headers, and server CORS headers
- Returns
- Preflight requirement, exact failure reasons, and corrected response policy
API rate-limit header analyzer
Read standard RateLimit fields, common X-RateLimit variants, Retry-After values, Shopify bucket headers, and reset timestamps in one local report.
- Reads
- Raw response headers
- Returns
- Remaining budget, reset time, safe pace, and header conflicts
Exponential backoff and idempotency planner
Build a bounded retry schedule, compare jitter strategies, and flag duplicate-side-effect risk for POST, PATCH, and webhook delivery workflows.
- Reads
- Method, attempts, base delay, cap, jitter, and idempotency
- Returns
- Attempt timeline, cumulative wait, and replay-risk notes
OpenAPI breaking-change impact checker
Compare two JSON OpenAPI documents by operation and schema meaning. Classify removed endpoints, newly required inputs, narrowed enums, and response changes.
- Reads
- Base and candidate OpenAPI JSON
- Returns
- Breaking, risky, and additive change ledger
LLM and MCP tool schema compiler
Compile a canonical JSON tool contract for OpenAI strict tools, Anthropic, Gemini, MCP 2025-11-25, or the MCP 2026 release candidate.
- Reads
- JSON Schema or provider tool wrapper
- Returns
- Target JSON, path diagnostics, repairs, and lossy-transform notes
READING ORDERNOTE FIRST
Every tool has a note behind it.
If a result surprises you, the linked field note explains the rule and cites the provider or standards document it came from.
HTTP 429 field note
Read the note →T02CORS preflight failed: compare the request and response policyBrowser policy field note
Read the note →T03RateLimit-Limit, Remaining, and Reset: calculate a safe request paceAPI header reference
Read the note →T04API retries: exponential backoff, jitter, caps, and stop conditionsReliability pattern
Read the note →T05Detect breaking changes in agent tool contractsVersioning guide
Read the note →T06JSON Schema to OpenAI strict tool compilerInteractive converter
Read the note →Workbench FAQ
Before you paste
Is anything I paste uploaded?
No. Every workbench parses and computes in the active browser tab. There is no account, no upload step, and no request to an APITC endpoint carrying your evidence.
Do the tools call the API I am debugging?
No. They reason about the evidence you provide — a response, a set of headers, a schema, or a policy — rather than reproducing the request. That is deliberate: it keeps credentials out of the process and makes the result explainable.
Are they free?
Yes, and they stay free without a sign-up. Each tool links to the field note and primary source behind the rule it applies, so you can verify the reasoning rather than trust the output.
CONTINUEREFERENCE SECTIONS
Status codes are the first branch. Provider codes, headers, and request state narrow the repair.
Open section →Reference deskHTTP and API header referenceRate budget, authentication challenge, cache validator, and CORS policy all arrive as header fields.
Open section →Reliability deskAPI reliability protocolsRetry policy, idempotency, pagination, and error shape are architecture decisions, not implementation details.
Open section →