Bug: --continue flag uses wrong model ID for EU region (Bedrock)

[jr42]

Description

When using Claude Code with AWS Bedrock in eu-central-1 region, the --continue flag fails because it attempts to use the US Haiku model identifier which is not available in EU regions.

Error Message

% claude --continue

▗ ▗   ▖ ▖  Claude Code v2.0.25
           Sonnet 4.5 · API Usage Billing
  ▘▘ ▝▝    ~/Develop/claude-code-stats

> Warmup 
  ⎿  API Error (us.anthropic.claude-3-5-haiku-20241022-v1:0): 400 The provided model identifier is invalid.

% claude           

▗ ▗   ▖ ▖  Claude Code v2.0.25
           Sonnet 4.5 · API Usage Billing
  ▘▘ ▝▝    ~/Develop/claude-code-stats

Expected Behavior

When using --continue with AWS Bedrock in eu-central-1, Claude Code should use the EU-compatible model identifier:

• eu.anthropic.claude-3-5-haiku-20241022-v1:0 (EU Haiku)

Instead of:

• us.anthropic.claude-3-5-haiku-20241022-v1:0 (US Haiku)
• Entire session being lost (won't appear anymore with --resume)

Environment

• Claude Code Version: v2.0.25
• Platform: macOS (Darwin 24.6.0)
• AWS Region: eu-central-1 (confirmed via AWS_DEFAULT_REGION)
• Provider: AWS Bedrock (CLAUDE_CODE_USE_BEDROCK=1)
• Primary Model: Sonnet 4.5 (works fine for new sessions)

Relevant Environment Variables

AWS_DEFAULT_REGION=eu-central-1
CLAUDE_CODE_USE_BEDROCK=1
CLAUDE_CODE_ENTRYPOINT=cli

Steps to Reproduce

1. Configure Claude Code to use AWS Bedrock in eu-central-1 region
2. Set environment: export AWS_DEFAULT_REGION=eu-central-1
3. Set environment: export CLAUDE_CODE_USE_BEDROCK=1
4. Start a new session: claude (works fine)
5. Try to continue the session: claude --continue
6. Error occurs: "The provided model identifier is invalid"

Root Cause

The warmup phase when using --continue appears to be hardcoded to use US model identifiers (us.anthropic.claude-3-5-haiku-20241022-v1:0) regardless of the AWS region configuration.

Impact

• --continue is completely broken for all EU Bedrock users
• No workaround available - users cannot resume previous sessions
• Forces users to start new sessions every time, losing conversation context

Suggested Fix

Claude Code should:

1. Detect the AWS region from environment (AWS_DEFAULT_REGION) or Bedrock configuration
2. Use region-appropriate model identifiers for all operations including --continue
3. Map us.* models to eu.* models when in EU regions
4. Apply this logic consistently across all warmup and model selection code paths

Example Region Mapping

const modelIdByRegion = {
  'us-east-1': 'us.anthropic.claude-3-5-haiku-20241022-v1:0',
  'us-west-2': 'us.anthropic.claude-3-5-haiku-20241022-v1:0',
  'eu-central-1': 'eu.anthropic.claude-3-5-haiku-20241022-v1:0',
  'eu-west-1': 'eu.anthropic.claude-3-5-haiku-20241022-v1:0',
  'eu-west-2': 'eu.anthropic.claude-3-5-haiku-20241022-v1:0',
  // ... other regions
};

Workaround

None available. Users must avoid --continue and start new sessions each time.

[alexduros]

I'm also investigating cross-region issues. In your case @jr42, just pointing out that Claude Code documentation refers to AWS_REGION and not AWS_DEFAULT_REGION to select the proper region.

https://docs.claude.com/en/docs/claude-code/amazon-bedrock#3-configure-claude-code

[marcguyer]

I'm also investigating cross-region issues. In your case @jr42, just pointing out that Claude Code documentation refers to AWS_REGION and not AWS_DEFAULT_REGION to select the proper region.

Same behavior experienced here with AWS_REGION=eu-central-1.

[fchenebault]

Same issue affects WebFetch tool

This hardcoded model ID issue also affects the WebFetch tool in EU regions.

Error with WebFetch

API Error (us.anthropic.claude-3-5-haiku-20241022-v1:0): 400 The provided model identifier is invalid.

WebFetch internally uses a Haiku model to process web content, but it's hardcoded to use the US model ID regardless of region.

Environment

• Claude Code Version: v2.0.28
• AWS Region: eu-central-1
• Provider: AWS Bedrock (CLAUDE_CODE_USE_BEDROCK=1)

Workaround

Setting the environment variable fixes WebFetch:

export ANTHROPIC_DEFAULT_HAIKU_MODEL="eu.anthropic.claude-haiku-4-5-20251001-v1:0"

Note: Must use inference profile ID (with eu. prefix), not direct model ID. AWS Bedrock requires inference profiles for on-demand throughput.

Available EU Inference Profiles

aws bedrock list-inference-profiles --query 'inferenceProfileSummaries[?contains(inferenceProfileName, `Haiku`)]'

Returns:

• eu.anthropic.claude-3-haiku-20240307-v1:0 (Claude 3 Haiku)
• eu.anthropic.claude-haiku-4-5-20251001-v1:0 (Claude 4.5 Haiku)
• global.anthropic.claude-haiku-4-5-20251001-v1:0 (Global profile)

Root Cause

Same as --continue: hardcoded US model identifiers throughout Claude Code codebase. Affects multiple features:

• ✅ --continue flag (already documented in this issue)
• ✅ WebFetch tool (documented here)
• ❓ Potentially other internal tools using Haiku

Suggested Fix

The proposed region mapping solution would fix both --continue and WebFetch. Consider also supporting ANTHROPIC_DEFAULT_HAIKU_MODEL environment variable as an override mechanism.

[Hely0n]

I found a workaround:

type /model and change it to Opus and then revert it back to Default again

[github-actions[bot]]

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[vuon9]

pls fix it! 🙏