HopBase DocsCreate chat completion
OpenAI-compatible Chat Completions: shared by GPT, Gemini, GLM, Qwen, DeepSeek, Grok and other chat models.
/v1/chat/completionsGiven a list of messages, returns the model's reply. With the OpenAI SDK, just set the Base URL to https://api.hop-base.com/v1 and use an API key from the matching group.
The table lists only the fields the gateway checks, rewrites or rejects, plus values documented on each model page; OpenAI fields not listed are forwarded as-is, with ranges per the model's official spec. The whole request body is capped at 60 MB; larger bodies return 413.
Headers
Bearer sk-…: an API key created in the console under API keys; its group must include the requested model
Body parametersJSON
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Conversation messages. Missing returns 400 missing messages field; an empty array returns 400 messages must not be an empty array
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Output cap. The gateway does not truncate or rewrite it; the limit follows the model's official spec, and values above it return an error from the model
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
auto / none / required or a specific function, forwarded as-is
Sampling temperature, forwarded as-is; range per the model's official spec
Nucleus sampling, forwarded as-is; range per the model's official spec
Reasoning effort. Values vary by model; select a model family above to see them
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuescodex-auto-reviewgpt-5.3-codex-sparkgpt-5.4gpt-5.4-minigpt-5.5gpt-5.6-solgpt-5.6-terragpt-6-astragpt-6-lunagpt-6-sol
Conversation messages. Missing returns 400 missing messages field; an empty array returns 400 messages must not be an empty array
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Output cap. The gateway does not truncate or rewrite it; the limit follows the model's official spec, and values above it return an error from the model
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
auto / none / required or a specific function, forwarded as-is
Sampling temperature, forwarded as-is; range per the model's official spec
Nucleus sampling, forwarded as-is; range per the model's official spec
Reasoning effort. Values vary by model; select a model family above to see them
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesgemini-2.5-flashgemini-2.5-flash-litegemini-2.5-progemini-3-flash-previewgemini-3.1-flash-litegemini-3.1-flash-lite-previewgemini-3.1-pro-previewgemini-3.1-pro-preview-customtoolsgemini-3.5-flashgemini-3.5-flash-litegemini-3.6-flashgemini-3.7-flashgemini-3.8-flash
Only text and image_url content parts are read. image_url accepts base64 data URLs only (public links return 400 image_url only supports data URLs (base64-embedded images)); input_audio, file and video_url are silently dropped; role: "tool" is sent as user text; no usable content returns 400
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
If max_completion_tokens is also sent, max_tokens wins. Thinking tokens count toward this cap; 4096 or more is recommended
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
auto / none / required or a specific function, forwarded as-is
Sampling temperature, forwarded as-is; range per the model's official spec
Nucleus sampling, forwarded as-is; range per the model's official spec
none / minimal → thinking budget 0; medium → 8192; high → 24576; low and other values keep the model default
Valuesnoneminimallowmediumhigh
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesglm-5.3
Non-empty array, text only; images return 400. 1M context
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Shared by thinking and answer. Out of range returns 400 max_tokens invalid: allowed range [1,131072]
Range1–131072
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
Same as OpenAI. Returned tool results must match a call ID from the previous turn, otherwise 400 No tool call found for function call output
Default"auto"
Sampling temperature, forwarded as-is; range per the model's official spec
Nucleus sampling, forwarded as-is; range per the model's official spec
Always thinks: values that disable thinking, such as none, return 400
Valueslowhighmax
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesglm-5.3-flash
Non-empty array; may contain text, images, video and files. 1M context
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Up to 128K (official cap), shared by thinking and answer
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
auto / none / required or a specific function, forwarded as-is
No gateway range; 1 recommended
No gateway range; 0.95 recommended
max recommended; thinking can only be on, not off
Valueslowhighmax
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
Recommended true when streaming with tools, so tool arguments stream incrementally
Defaultfalse
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesqwen3.7-flashqwen3.7-maxqwen3.7-plusqwen3.8-flashqwen3.8-max
Non-empty array; qwen3.7-max is text only, other models accept images and video; image width and height must exceed 10 px. qwen3.8-max measured input cap is 991,808 tokens; beyond that returns 400 Range of input length should be [1, 991808]
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Up to 131,072 (official cap)
Range≤ 131072
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
Same as OpenAI. In thinking mode it cannot be required or a specific function; doing so returns 400
Default"auto"
Sampling temperature, forwarded as-is; range per the model's official spec
Nucleus sampling, forwarded as-is; range per the model's official spec
Values verified to work
Valueslowhighmax
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
Qwen-specific, passed through
Cannot be set together with reasoning_effort; doing so returns 400
Qwen-specific, passed through
JSON mode, same behavior as the official API
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesdeepseek-v4-flash-202605deepseek-v4-pro-202606deepseek-v4.1-flash
Non-empty array; role is system / user / assistant / tool / developer. Image input on deepseek-v4.1-flash only: image_url.url may be a data: URI or an https:// link
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
Non-negative integer; output caps: V4.1 Flash and V4 Flash 384,000, V4 Pro 393,216. Shared by thinking and answer; negative values return 400; values above the cap do not error, the output is silently truncated
Range≥ 0
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools in OpenAI function tools format, forwarded as-is.
Always function
Function name
What the function does; the model uses it to decide whether to call it
JSON Schema for the parameters
auto / none / required / a specific function
Default"auto"
Values above 2 return 400 expected a value <= 2
Range0–2
Nucleus sampling, forwarded as-is; range per the model's official spec
Values verified to work
Valueslowmediumhigh
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
{"type": …}; other values (such as auto) return 400. On by default for V4.1 Flash
Valuesenableddisabledadaptive
Prefix continuation: only allowed on the last assistant message
Defaultfalse
A model ID in the current key's group; GET /v1/models is authoritative. If the group does not include the model, returns 404 model_not_found; image models such as gpt-image-* return 400 image models do not support Chat Completions, please use the Images API on this endpoint
Valuesgrok-4.20-0309-reasoninggrok-4.20-multi-agent-0309grok-4.3grok-4.5grok-4.6
Conversation messages. Missing returns 400 missing messages field; an empty array returns 400 messages must not be an empty array
Items≥ 1
system / user / assistant / tool, in OpenAI format
A string, or an array of content parts. Part {"type": "text", "text": …}; vision models also accept {"type": "image_url", "image_url": {"url": …}}. Per-model image requirements are shown under the model picker above
text or image_url
Text when type is text
Image when type is image_url
HTTP(S) link or data: URI; supported forms vary by model
assistant only: the tool calls returned by the model in the previous turn, sent back unchanged
tool only: must match tool_calls[].id from the previous turn
No gateway cap; bounded by the context window. Officially includes reasoning tokens
Same as max_tokens; the newer OpenAI field name
true returns SSE; see Streaming events for the event format
Defaultfalse
Streaming options
When streaming, pass true to receive a final event carrying only usage (with empty choices); if omitted it is not sent. Billing is unaffected
Defaultfalse
Function tools and server-side tools; server-side tools are billed per call
auto / none / required or a specific function, forwarded as-is
0–2 (official)
Range0–2
0–1 (official); officially recommended to use either this or temperature, not both
Range0–1
grok-4.6: low / medium / high / xhigh; grok-4.5: low / medium / high (official). Only these two models expose it officially; reasoning cannot be disabled
Valueslowmediumhighxhigh
Default"high"
Only priority / flex are kept; other values are removed before forwarding, without an error
Valuespriorityflex
Not supported (official): reasoning models reject it and return an error
Not supported (official)
Not supported (official)
Returns
200Success. Non-streaming returns chat.completion JSON; with stream: true it returns SSE (text/event-stream)
ID of this completion
Always chat.completion
Unix seconds
Model ID actually used
Candidate replies; most models return only 1
Index
Model reply
Always assistant
Reply text; null when the model only calls tools
Reasoning content (returned by DeepSeek and other models)
Functions the model wants to call; after running them, send the results back in role: "tool" messages
Call ID; put it in tool_call_id when returning the result
Function name
Arguments as a JSON string
stop / length / tool_calls, etc.; length means the output cap was hit
Token usage
Input tokens
Output tokens; whether reasoning tokens are included varies by model, see each model page
Total
Reasoning tokens (listed separately by some models)
Errors
messages, etc.missing_api_key / invalid_api_key / api_key_expired)insufficient_quota)model_not_found), or the path does not belong to the group (route_not_found)request_too_large)user_concurrency_limit / apikey_concurrency_limit), with Retry-After