Apex API

callstack/apex/chat

Apex from Callstack supports React Native and React application development. This chat API accepts text / images, provides a 262,144-token input budget and accepts max_tokens up to 131,072. Stream Apex’s text as it arrives, or let a function-call result supply the evidence for the next step in React Native development with Apex.

Input $0.50Output $3per 1 million tokensCached input $0.20

Run model View API

Send a request

Examples use the selected endpoint’s public parameter definitions. Replace the API key and example media, then send the request from your server.

SDKs & integrations

POSThttps://api.spicyapi.ai/v1/chat/completions

API authentication

Keep the API key in the server environment variable SPICY_API_KEY. Use Bearer authentication and Content-Type: application/json for JSON requests.

Authorization: Bearer $SPICY_API_KEY

curl --fail-with-body -sN https://api.spicyapi.ai/v1/chat/completions \
  -H "Authorization: Bearer $SPICY_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "model": "callstack/apex/chat",
  "messages": [
    {
      "role": "user",
      "content": "Summarise the following release notes into three bullet points."
    }
  ],
  "stream": true
}' \
  | jq --unbuffered -Rrj 'select(startswith("data: ")) | .[6:] | select(. != "[DONE]") | fromjson | if .error then "\n[error] \(.error.message)\n" else (.choices[0].delta.content? // empty) end'

Generated from this model’s input schema — the same one the API validates every request against.

Keep one Idempotency-Key for each logical request. After a network interruption, do not automatically resend with a new key; retain request_id to investigate the accepted request. Idempotency does not replay an earlier chat stream.

Input parameters

Place the model parameters directly in the JSON request body alongside model. This endpoint does not use an input wrapper.

messagesarray<object>Required

For React Native development with Apex, supply the conversation and the evidence as text in order, and connect each tool result to its original tool_call_id.

Default: Not specified
Constraints: minItems:1
maxItems:256

messages[].rolestringRequired within object

Role of the message author.

Default: Not specified
Allowed values: "system""developer""user""assistant""tool"

messages[].namestringOptional

Optional name identifying the speaker within its role.

Default: Not specified

messages[].contentstring | array | nullOptional

Message content, either plain text or a list of content parts.

Default: Not specified

{
  "type": [
    "string",
    "array",
    "null"
  ],
  "items": {
    "oneOf": [
      {
        "type": "object",
        "required": [
          "type",
          "text"
        ],
        "properties": {
          "text": {
            "type": "string"
          },
          "type": {
            "const": "text"
          }
        }
      },
      {
        "type": "object",
        "required": [
          "type",
          "image_url"
        ],
        "properties": {
          "type": {
            "const": "image_url"
          },
          "image_url": {
            "type": "object",
            "required": [
              "url"
            ],
            "properties": {
              "url": {
                "type": "string"
              }
            }
          }
        }
      }
    ]
  },
  "description": "Message content, either plain text or a list of content parts."
}

messages[].tool_callsarray<object>Optional

Tool calls the assistant requested in this message.

Default: Not specified

messages[].tool_call_idstringOptional

Identifier of the tool call this message answers. Required on tool messages.

Default: Not specified

messages[].reasoning_contentstringOptional

Reasoning text from a previous assistant reply, preserved when continuing a tool conversation.

Default: Not specified

{
  "type": "array",
  "x-ui": {
    "order": 100,
    "widget": "chat-messages",
    "primary": true
  },
  "items": {
    "type": "object",
    "allOf": [
      {
        "if": {
          "required": [
            "reasoning_content"
          ]
        },
        "then": {
          "properties": {
            "role": {
              "const": "assistant"
            }
          }
        }
      }
    ],
    "required": [
      "role"
    ],
    "properties": {
      "name": {
        "type": "string",
        "description": "Optional name identifying the speaker within its role."
      },
      "role": {
        "enum": [
          "system",
          "developer",
          "user",
          "assistant",
          "tool"
        ],
        "type": "string",
        "description": "Role of the message author."
      },
      "content": {
        "type": [
          "string",
          "array",
          "null"
        ],
        "items": {
          "oneOf": [
            {
              "type": "object",
              "required": [
                "type",
                "text"
              ],
              "properties": {
                "text": {
                  "type": "string"
                },
                "type": {
                  "const": "text"
                }
              }
            },
            {
              "type": "object",
              "required": [
                "type",
                "image_url"
              ],
              "properties": {
                "type": {
                  "const": "image_url"
                },
                "image_url": {
                  "type": "object",
                  "required": [
                    "url"
                  ],
                  "properties": {
                    "url": {
                      "type": "string"
                    }
                  }
                }
              }
            }
          ]
        },
        "description": "Message content, either plain text or a list of content parts."
      },
      "tool_calls": {
        "type": "array",
        "items": {
          "type": "object"
        },
        "description": "Tool calls the assistant requested in this message."
      },
      "tool_call_id": {
        "type": "string",
        "description": "Identifier of the tool call this message answers. Required on tool messages."
      },
      "reasoning_content": {
        "type": "string",
        "description": "Reasoning text from a previous assistant reply, preserved when continuing a tool conversation."
      }
    },
    "additionalProperties": false
  },
  "maxItems": 256,
  "minItems": 1,
  "description": "Conversation history in order, oldest message first."
}

tool_choicestring | objectOptional

Choose auto, none, required or a specific function for Apex, then preserve the returned call ID when continuing React Native development with Apex.

Default: Not specified

parallel_tool_callsbooleanOptional

Allow Apex to propose independent function calls together when React Native development with Apex needs more than one external result.

Default: true

toolsarray<object>Optional

Give Apex OpenAI-format function definitions for React Native development with Apex; the model proposes arguments and your application validates and executes the operation.

Default: Not specified
Constraints: maxItems:128

top_pnumberOptional

Use top_p as Apex’s nucleus-sampling control; when tuning React Native development with Apex, vary this or temperature separately so the change remains interpretable.

Default: Not specified
Constraints: minimum:0.01
maximum:1

temperaturenumberOptional

Apex accepts temperature from 0 to 2; keep other sampling controls steady when comparing wording for React Native development with Apex.

Default: Not specified
Constraints: minimum:0
maximum:2

stopstring | arrayOptional

End Apex’s generated text at one supplied stop sequence or any of up to four; the matching sequence itself is left out of the answer.

Default: Not specified
Constraints: minLength:1
minItems:1
maxItems:4

reasoning_effortstringOptional

Apex exposes none, low, medium, xhigh, starting at medium; compare effort settings on React Native development with Apex because deeper reasoning can increase output tokens and waiting time.

Default: "medium"
Allowed values: "none""low""medium""xhigh"

max_tokensintegerOptional

Budget Apex’s visible answer and billable reasoning together in max_tokens; its default is 4096, its ceiling is 131072, and a larger cap does not alter the token rate.

Default: 4096
Constraints: minimum:1
maximum:131072

{
  "type": "object",
  "required": [
    "messages"
  ],
  "x-pricing": {
    "billingMode": "formula",
    "variantFields": []
  },
  "properties": {
    "stop": {
      "type": [
        "string",
        "array"
      ],
      "x-ui": {
        "order": 65,
        "widget": "text",
        "affects_price": false
      },
      "items": {
        "type": "string",
        "maxLength": 32,
        "minLength": 1
      },
      "maxItems": 4,
      "minItems": 1,
      "minLength": 1,
      "description": "Sequences that end the reply as soon as the model writes one; the matched text is not returned."
    },
    "tools": {
      "type": "array",
      "x-ui": {
        "order": 35,
        "widget": "json"
      },
      "items": {
        "type": "object"
      },
      "maxItems": 128,
      "description": "Tool definitions the model may call."
    },
    "top_p": {
      "type": "number",
      "x-ui": {
        "step": 0.01,
        "order": 40,
        "widget": "slider"
      },
      "maximum": 1,
      "minimum": 0.01,
      "description": "Nucleus sampling threshold. Lower values keep only the most likely tokens."
    },
    "messages": {
      "type": "array",
      "x-ui": {
        "order": 100,
        "widget": "chat-messages",
        "primary": true
      },
      "items": {
        "type": "object",
        "allOf": [
          {
            "if": {
              "required": [
                "reasoning_content"
              ]
            },
            "then": {
              "properties": {
                "role": {
                  "const": "assistant"
                }
              }
            }
          }
        ],
        "required": [
          "role"
        ],
        "properties": {
          "name": {
            "type": "string",
            "description": "Optional name identifying the speaker within its role."
          },
          "role": {
            "enum": [
              "system",
              "developer",
              "user",
              "assistant",
              "tool"
            ],
            "type": "string",
            "description": "Role of the message author."
          },
          "content": {
            "type": [
              "string",
              "array",
              "null"
            ],
            "items": {
              "oneOf": [
                {
                  "type": "object",
                  "required": [
                    "type",
                    "text"
                  ],
                  "properties": {
                    "text": {
                      "type": "string"
                    },
                    "type": {
                      "const": "text"
                    }
                  }
                },
                {
                  "type": "object",
                  "required": [
                    "type",
                    "image_url"
                  ],
                  "properties": {
                    "type": {
                      "const": "image_url"
                    },
                    "image_url": {
                      "type": "object",
                      "required": [
                        "url"
                      ],
                      "properties": {
                        "url": {
                          "type": "string"
                        }
                      }
                    }
                  }
                }
              ]
            },
            "description": "Message content, either plain text or a list of content parts."
          },
          "tool_calls": {
            "type": "array",
            "items": {
              "type": "object"
            },
            "description": "Tool calls the assistant requested in this message."
          },
          "tool_call_id": {
            "type": "string",
            "description": "Identifier of the tool call this message answers. Required on tool messages."
          },
          "reasoning_content": {
            "type": "string",
            "description": "Reasoning text from a previous assistant reply, preserved when continuing a tool conversation."
          }
        },
        "additionalProperties": false
      },
      "maxItems": 256,
      "minItems": 1,
      "description": "Conversation history in order, oldest message first."
    },
    "max_tokens": {
      "type": "integer",
      "x-ui": {
        "unit": "tokens",
        "order": 80,
        "widget": "number",
        "advanced": false,
        "affects_price": false
      },
      "default": 4096,
      "maximum": 131072,
      "minimum": 1,
      "description": "Maximum number of tokens to generate in the reply."
    },
    "temperature": {
      "type": "number",
      "x-ui": {
        "order": 50,
        "widget": "slider"
      },
      "maximum": 2,
      "minimum": 0,
      "description": "Sampling temperature. Higher values make the output more varied."
    },
    "tool_choice": {
      "type": [
        "string",
        "object"
      ],
      "x-ui": {
        "order": 30,
        "widget": "json"
      },
      "description": "Controls whether and which tool the model may call."
    },
    "reasoning_effort": {
      "enum": [
        "none",
        "low",
        "medium",
        "xhigh"
      ],
      "type": "string",
      "x-ui": {
        "order": 70,
        "widget": "radio"
      },
      "default": "medium",
      "description": "How much reasoning the model spends before answering."
    },
    "parallel_tool_calls": {
      "type": "boolean",
      "x-ui": {
        "order": 33,
        "widget": "switch",
        "affects_price": false
      },
      "default": true,
      "description": "Whether the model may request more than one tool call in a single turn."
    }
  },
  "x-image-token-limit": 32768,
  "x-input-token-limit": 262144,
  "additionalProperties": false
}

Read the result

With stream set to false, the request returns the completed chat response directly. Read choices[].message; no task polling is needed. Set stream to true when your client supports Server-Sent Events.

Completed response example

{
  "id": "chatcmpl_example",
  "object": "chat.completion",
  "created": 1788652800,
  "model": "callstack/apex/chat",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Here is a concise summary of the release notes."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 32,
    "completion_tokens": 14,
    "total_tokens": 46
  }
}

The response example is illustrative. usage reports token counts; token counts and charges depend on your actual request.

SDKs & integrations

Use SpicyAPI in your app, terminal, AI assistant or visual workflow. Choose a setup guide below.

SDKs

TypeScript · Python · Go · PHP · Java

CLI

Terminal commands and automation scripts.

MCP

Claude Code · Cursor · Codex

Agent Skill

Reusable instructions for your AI assistant.

n8n

Self-hosted community nodes and importable HTTP Request templates for n8n Cloud.

ComfyUI

Image, video and audio workflows on a node canvas.

More integrations

SillyTavern Telegram / Discord App proxy OpenAI SDK LangChain Vercel AI SDK

Browse ready-to-use workflows

This is a chat model, so it works wherever the OpenAI chat API works: keep your client, change the base URL, and select this model by its ID.

Point any OpenAI-compatible client here

export OPENAI_BASE_URL="https://api.spicyapi.ai/v1"
export OPENAI_API_KEY="$SPICY_API_KEY"

aider --model openai/callstack/apex/chat

Anything that speaks the OpenAI chat API works the same way — SDKs, the Vercel AI SDK, LangChain, aider, Cline. The MCP server and the spicyapi CLI cover asynchronous media tasks. Per-tool setup is in the developer hub.

Use it in SillyTavern and roleplay apps

In SillyTavern, RisuAI, Agnai or any app with an OpenAI-compatible setting, paste the base URL below and your API key, then pick callstack/apex/chat as the model. Browser calls are allowed, and sliders this model does not take are ignored instead of rejected.

Base URL: https://api.spicyapi.ai/v1
Model: callstack/apex/chat

SillyTavern guide RisuAI, Agnai and more SillyTavern extension

Use it in ComfyUI

Install the SpicyAPI nodes from ComfyUI Manager or with the command below, then pick callstack/apex/chat in the SpicyAPI Chat node to use this model inside a ComfyUI graph.

cd ComfyUI/custom_nodes
git clone https://github.com/spicyapi-ai/comfyui-spicyapi

Workflow examples Setup guide Source on GitHub

The embedded panel reads the same schema as this page, so it cannot drift from the API. If your docs need the content to be searchable, read the JSON under /api/embed/models/ and render it yourself.

<iframe src="https://spicyapi.ai/embed/en/models/callstack-apex/api?model=callstack%2Fapex%2Fchat" width="100%" height="560" loading="lazy" title="Request example" style="border:1px solid rgba(0,0,0,.12)"></iframe>

Open the panel

Workbench

Send a request

API authentication

Input parameters

Read the result

SDKs & integrations

Use it in SillyTavern and roleplay apps

Use it in ComfyUI