Get started with OpenAI GPT-5.5, GPT-5.4 models, and Codex on Amazon Bedrock | Amazon Web Services

OpenAI GPT-5.5, GPT-5.4, and Codex are now generally available through Amazon Bedrock. GPT-5.5 targets the most demanding coding, reasoning, and agentic workloads, while GPT-5.4 emphasizes price-performance. Customers can access the models through the Responses API and use Codex across CLI, desktop, IDE, and Xcode integrations, with regional processing and token-based pricing.

Model Access Through Amazon Bedrock

• Models are served through Bedrock’s next-generation inference engine and the OpenAI Responses API.
• GPT-5.5 is positioned for the hardest workloads; GPT-5.4 offers a balance of capability and cost.
• Processing remains within the selected Bedrock Region, supporting data residency requirements.
• Pricing is based on token usage, with no seat licenses or per-developer commitments.

Calling GPT Models Programmatically

• The OpenAI Python SDK can be configured with Bedrock’s OpenAI-compatible endpoint:
  • Install with pip install -U openai.
  • Set OPENAI_BASE_URL, OPENAI_API_KEY, and BEDROCK_OPENAI_MODEL_ID.
• Applications can call client.responses.create() with:
  • Developer and user messages
  • Configurable reasoning effort
  • Output verbosity controls
• The same endpoint can be called directly with curl.
• The Responses API supports multi-turn state, hosted and function tools, tool orchestration, and background or long-running work.

Using Codex with Bedrock

• Codex is available through the Codex CLI, desktop app, VS Code, JetBrains, and Xcode integrations.
• It supports:
  • A Bedrock API key via AWS_BEARER_TOKEN_BEDROCK
  • The AWS SDK credential chain as a fallback
• Configure the model and Region in ~/.codex/config.toml, for example:
  • Model: openai.gpt-5.5
  • Provider: amazon-bedrock
  • Region: us-east-2
• Other supported model IDs include openai.gpt-5.4, openai.gpt-oss-120b, and openai.gpt-oss-20b.
• Desktop and VS Code users can place environment variables in ~/.codex/.env.
• Applications must be restarted after configuration changes.

Latency and Scaling Considerations

• Actual latency depends on reasoning effort, response length, tool calls, background execution, Region, quotas, throttling, prompt size, and cache hits.
• AWS recommends starting GPT-5.5 with medium reasoning effort.
• GPT-5.4 should use an explicitly chosen effort level rather than relying on its default of none.
• Bedrock’s inference engine is designed to provision capacity dynamically.
• During demand spikes, requests may be queued instead of rejected.

Regional Availability

• GPT-5.5 is initially available in the US East (Ohio) Region.
• GPT-5.4 is available in US East (Ohio) and US West (Oregon).
• Additional Regions may be added over time.

Teams needing advanced coding and reasoning capabilities can now use OpenAI models and Codex through Bedrock while retaining AWS authentication, regional processing, and usage-based pricing. Evaluate reasoning effort, latency, quotas, and regional availability before moving workloads into production.