Research Basis via OpenAI SDK: When using task processors (lite, base, core) with the Chat API, the response includes a basis field with citations, reasoning, and confidence levels. Access it via response.basis in Python or (response as any).basis in TypeScript. See Basis documentation for details. Important OpenAI Compatibility Limitations
API Behavior
Here are the most substantial differences from using OpenAI:
- Multimodal input (images/audio) is not supported and will be ignored.
- Prompt caching is not supported.
- Most unsupported fields are silently ignored rather than producing errors. These are all documented below.
Detailed OpenAI Compatible API Support
Request Fields
Simple Fields
| Field | Support Status |
|---|
| model | Use speed, lite, base, or core |
| response_format | Fully supported |
| stream | Fully supported |
| max_tokens | Ignored |
| max_completion_tokens | Ignored |
| stream_options | Ignored |
| top_p | Ignored |
| parallel_tool_calls | Ignored |
| stop | Ignored |
| temperature | Ignored |
| n | Ignored |
| logprobs | Ignored |
| metadata | Ignored |
| prediction | Ignored |
| presence_penalty | Ignored |
| frequency_penalty | Ignored |
| seed | Ignored |
| service_tier | Ignored |
| audio | Ignored |
| logit_bias | Ignored |
| store | Ignored |
| user | Ignored |
| modalities | Ignored |
| top_logprobs | Ignored |
| reasoning_effort | Ignored |
Messages Array Fields
| Field | Support Status |
|---|
| messages[].role | Fully supported |
| messages[].content | String only |
| messages[].name | Fully supported |
| messages[].tool_calls | Ignored |
| messages[].tool_call_id | Ignored |
| messages[].function_call | Ignored |
| messages[].audio | Ignored |
| messages[].modalities | Ignored |
The content field only supports string values. Structured content arrays (e.g., for multimodal inputs with text and image parts) are not supported.
Response Fields
| Field | Support Status |
|---|
| id | Always empty |
| choices[] | Will always have a length of 1 |
| choices[].finish_reason | Always empty |
| choices[].index | Fully supported |
| choices[].message.role | Fully supported |
| choices[].message.content | Fully supported |
| choices[].message.tool_calls | Always empty |
| object | Always empty |
| created | Fully supported |
| model | Always empty |
| finish_reason | Always empty |
| content | Fully supported |
| usage.completion_tokens | Always empty |
| usage.prompt_tokens | Always empty |
| usage.total_tokens | Always empty |
| usage.completion_tokens_details | Always empty |
| usage.prompt_tokens_details | Always empty |
| choices[].message.refusal | Always empty |
| choices[].message.audio | Always empty |
| logprobs | Always empty |
| service_tier | Always empty |
| system_fingerprint | Always empty |
Parallel-Specific Response Fields
The following fields are Parallel extensions not present in the OpenAI API:
| Field | Support Status |
|---|
| basis | Supported with task processors (lite, base, core) |
Error Message Compatibility
The compatibility layer maintains approximately the same error formats as the OpenAI API.
While the OpenAI SDK automatically manages headers, here is the complete list of headers supported by Parallel’s API for developers who need to work with them directly.
| Field | Support Status |
|---|
| authorization | Fully supported |
| x-ratelimit-limit-requests | Ignored |
| x-ratelimit-limit-tokens | Ignored |
| x-ratelimit-remaining-requests | Ignored |
| x-ratelimit-remaining-tokens | Ignored |
| x-ratelimit-reset-requests | Ignored |
| x-ratelimit-reset-tokens | Ignored |
| retry-after | Ignored |
| x-request-id | Ignored |
| openai-version | Ignored |
| openai-processing-ms | Ignored |
