Diagnose OpenAI-Compatible API Failures.

One endpoint. Six real probes. Evidence for the network, auth, model, server, and SDK layer—before you lose another hour blaming the wrong thing.

01NetworkDNS · TLS · CORS
02AuthenticationKey · policy
03ModelName · capability
04Server implementationShape · streaming
05SDK contractTypes · conventions

Test the endpoint, not your assumptions.

Run six focused probes and receive evidence for each result.

OpenAI-Compatible API Tester

Check model listing, basic chat, SSE streaming, tool calling, the tool-result round trip, and JSON mode.

Input
Base URL, API key, model
Output
Evidence, fixes, reproduction code
Open the API tester

Example report

Illustrative report · generated with the real P0 report shape

Example endpointexample-model
SUITE 2026.07-p0642 MS
6probes
3PASS1PARTIAL1FAIL1SKIPPED
StatusProbeFindingLatency
PASSModel ListP0

Reads /models, confirms models are enumerable, and checks whether the entered model ID is present.

24 ms
PASSBasic Chat CompletionP0

Sends a minimal text request and checks whether the response shape can be parsed by OpenAI SDKs.

41 ms
PARTIALStreaming (SSE)P0

The stream completes, but one frame uses a provider-specific field.

58 ms
FAILSingle Tool CallingP0

The endpoint accepted tools but did not return a tool_calls array.

75 ms
SKIPPEDTool Result Round TripP0

Skipped because the tool-call prerequisite did not pass.

92 ms
PASSJSON ModeP0

Uses response_format: json_object and checks whether the endpoint reliably returns valid JSON.

109 ms
Stopped at server implementationThe endpoint accepted tools but returned no tool_calls array.
Recommended fix

Enable tool calling for this model or update the compatibility server.

Troubleshooting guides

Fast answers for configuration and compatibility failures, backed by requests you can reproduce.

Base URL · ConfigurationFind the correct OpenAI-compatible API rootRead field note Tools · CapabilityTest and fix OpenAI-compatible tool callingRead field note Streaming · SSEFind malformed or incomplete streaming responsesRead field note Browser · CORSSeparate browser policy failures from endpoint failuresRead field note View all guides

What this proves

A green response is not compatibility. Each probe records assertions, the failure layer, expected versus actual data, a repair path, and a shareable reproduction.

Methodology & privacy