As previewed at What’s Next with AWS 2026, OpenAI GPT-5.5, GPT-5.4 models, and Codex are now available on Amazon Bedrock, giving you access to frontier models and a coding agent for software development.

According to OpenAI, GPT-5.5 and GPT-5.4 models are excellent for coding, reasoning, agentic workflows, and complex professional work. Use GPT-5.5 for the hardest customer workloads and GPT-5.4 for the best price-performance. Both models are accessible through the Responses API on Amazon Bedrock’s next-generation inference engine, built for high performance, reliability, and security.

Codex is the OpenAI coding agent for AI-powered software development. According to OpenAI, more than 4 million developers use Codex every week to write, refactor, debug, test, and validate code across large codebases. With GPT-5.5 powering inference, Codex introduces a new class of intelligence optimized for complex, long-horizon developer workflows. You can use the Codex App, the Codex CLI, and IDE integrations with Visual Studio Code, JetBrains, and Xcode, with all model inference routed through the Responses API on Amazon Bedrock.

For customers with data residency requirements, all processing stays within the Bedrock Region you select. You pay per token with no seat licenses and no per-developer commitments.

GPT-5.5 and GPT-5.4 Models on Bedrock

You can access the models programmatically using the OpenAI Responses API to call the bedrock-mantle endpoints through the OpenAI SDK or command-line tools such as curl.

Start by installing the OpenAI SDK for Python:

pip install -U openai

Set the environment variables for authentication:

export OPENAI_BASE_URL="https://bedrock-mantle.us-east-2.api.aws/openai/v1"
export OPENAI_API_KEY="<BEDROCK_API_KEY>"
export BEDROCK_OPENAI_MODEL_ID="openai.gpt-5.5"

Here is a sample Python code to call the GPT-5.5 model on Bedrock:

import os
from openai import OpenAI

client = OpenAI(
    base_url=os.environ["OPENAI_BASE_URL"],
    api_key=os.environ["OPENAI_API_KEY"],
)

response = client.responses.create(
    model=os.environ["BEDROCK_OPENAI_MODEL_ID"],
    input=[
        {
            "role": "developer",
            "content": "You are a software engineer with excellent AWS cloud knowledge. Be concise and practical.",
        },
        {
            "role": "user",
            "content": "Design a distributed architecture on AWS in Python that should support 100k requests per second across multiple geographic regions.",
        },
    ],
    reasoning={"effort": "medium"},
    text={"verbosity": "low"},
)

print(response.output_text)

You can also call the model endpoint directly using curl:

curl "$OPENAI_BASE_URL/responses" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -d '{
    "model": "openai.gpt-5.5",
    "input": [
      {
        "role": "developer",
        "content": "You are a software engineer with excellent AWS cloud knowledge."
      },
      {
        "role": "user",
        "content": "Design a distributed architecture on AWS in Python that should support 100k requests per second across multiple geographic regions."
      }
    ],
    "reasoning": {"effort": "medium"},
    "text": {"verbosity": "low"}
  }'

Use the Responses API when you need model-managed multi-turn state, hosted tools, function tools, richer tool orchestration, or background and long-running work. To learn more, visit the OpenAI Cookbook Responses examples and the getting started guide.

Using OpenAI Codex with GPT-5.5 on Amazon Bedrock

You can download the Codex CLI, Codex App, or Codex VS Code extension and configure Bedrock for model inference. Codex supports two Bedrock authentication pathways: Amazon Bedrock API key or AWS SDK credential chain. If you set AWS_BEARER_TOKEN_BEDROCK, Codex uses it first; otherwise it falls back to the AWS SDK credential chain.

Set AWS_BEARER_TOKEN_BEDROCK in the environment that Codex will read:

export AWS_BEARER_TOKEN_BEDROCK=<your-bedrock-api-key>

Then configure your preferred Region and set the model ID to openai.gpt-5.5 in ~/.codex/config.toml, which is required for Bedrock API-key authentication. You can also choose openai.gpt-5.4, openai.gpt-oss-120b, or openai.gpt-oss-20b. For the desktop app or VS Code extension, put any required environment variables in ~/.codex/.env.

model = "openai.gpt-5.5"
model_provider = "amazon-bedrock"
[model_providers.amazon-bedrock.aws]
region = "us-east-2"

Restart the desktop app or VS Code extension after changing ~/.codex/config.toml or ~/.codex/.env. In Codex CLI, you should see a /status tab that looks like this:

Codex CLI status tab showing Bedrock connection

In Codex App, you can use the GPT-5.5 model through Amazon Bedrock inference:

Codex App using GPT-5.5 on Amazon Bedrock

To learn more about configuring Codex to use OpenAI models on Amazon Bedrock, visit Use Codex with Amazon Bedrock.

Things to Know

  • Model latency: OpenAI positions GPT-5.5 as fast and GPT-5.4 as medium speed, but customer-perceived latency depends on reasoning effort, output length, tool calls, background mode, Region, quotas, throttling, prompt size, and cache hits. Start GPT-5.5 at medium effort. Start GPT-5.4 with effort set explicitly rather than relying on its none default.
  • Scaling and capacity: Bedrock’s new inference engine is designed to rapidly provision and serve capacity across many different models. When accepting requests, it prioritizes keeping steady-state workloads running and ramps usage and capacity rapidly in response to changes in demand. During periods of high demand, requests are queued rather than rejected.

Availability

OpenAI GPT models and Codex on Amazon Bedrock are available today: GPT-5.5 in the US East (Ohio) Region, and GPT-5.4 in the US East (Ohio) and US West (Oregon) Regions. Check the full list of Regions for future updates. To learn more, visit the OpenAI on Amazon Bedrock page and the Amazon Bedrock pricing page.

Send feedback to AWS re:Post for Amazon Bedrock or through your usual AWS Support contacts.

Updated June 1, 2026 – GPT-5.5 and GPT-5.4 models now support the Responses API only on Amazon Bedrock; console support is coming soon.

Updated June 3, 2026 – Amazon Bedrock now supports GPT-5.4 from OpenAI in the AWS GovCloud (US-West) Region.

Updated June 7, 2026 – GPT-5.5 and GPT-5.4 models are now available in the new Amazon Bedrock console.