GPT-5.3 Codex Spark API
About
Build advanced reasoning agents with GPT-5.3 Codex Spark, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers cost-effective pricing at $1.75/1M input and $14.00/1M output tokens, native tool calling support. Access GPT-5.3 Codex Spark via the OpenCode API with up to 128K output tokens.
Capabilities
Input Modalities
text
Output Modalities
text
Reasoning
Yes
Structured Output
Yes
Tool Use
Yes
WeightsClosed
Temperature
Fixed
Attachment
Not Supported
Limits
Context Window
128K
Tokens
Input Limit
128K
Tokens
Max Output
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
$1.75
Output
$14.00
Caching (per 1M tokens)
Read
$0.17
Frequently Asked Questions
GPT-5.3 Codex Spark by OpenCode costs $1.75 per 1M input tokens and $14.00 per 1M output tokens. Cached reads cost $0.17 per 1M tokens.
Model Details
ID
gpt-5.3-codex-spark
Provider
OpenCodeFamily
gpt-codex-spark
Release Date
Feb 12, 2026
Knowledge Cutoff
Aug 31, 2025
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
OPENCODE_API_KEY
API Base URL
https://opencode.ai/inference/openai/v1