Ollama / Ollama

Ollama Launch Claude Fails with API Error 400 When CLAUDE_CODE_USE_BEDROCK Is Set

Fix ollama launch claude 400 error when CLAUDE_CODE_USE_BEDROCK is enabled in settings Includes evidence for Ollama troubleshooting demand.

Source-backed Last updated May 12, 2026 1 source Needs local verification

Category: Ollama
Error signature: API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 12, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Ollama, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name is a Ollama failure pattern reported for developers trying to fix ollama launch claude 400 error when claude_code_use_bedrock is enabled in settings. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Active GitHub issue on ollama/ollama (May 2026). ollama launch claude sets the model name to the pulled local model (e.g., gemma4) but does not override backend routing. When CLAUDE_CODE_USE_BEDROCK=1 is in Claude Code settings.json, requests route to AWS Bedrock which rejects the model name with 'API Error (gemma4): 400'.

Common causes

When developers run ollama launch claude to use a local Ollama model with Claude Code, but have CLAUDE_CODE_USE_BEDROCK=1 set in ~/.claude/settings.json, Claude Code routes requests to AWS Bedrock instead of Ollama. Bedrock rejects the local model name (e.g., 'gemma4') with a 400 error. This is a subtle configuration conflict that's hard to diagnose without knowing both tools' settings interactions.
Active GitHub issue on ollama/ollama (May 2026). ollama launch claude sets the model name to the pulled local model (e.g., gemma4) but does not override backend routing. When CLAUDE_CODE_USE_BEDROCK=1 is in Claude Code settings.json, requests route to AWS Bedrock which rejects the model name with 'API Error (gemma4): 400'.

Quick fixes

Confirm the exact error signature matches API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name.
Check the Ollama account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name exactly before applying the quick fix.
Compare the failing environment with Ollama versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name mean in Ollama?

API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name indicates the workflow described by "Ollama Launch Claude Fails with API Error 400 When CLAUDE_CODE_USE_BEDROCK Is Set" failed in a Ollama context. Start by confirming the exact signature and the component that emitted it.

What should I check first for API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name?

Check whether this cause matches your environment: When developers run ollama launch claude to use a local Ollama model with Claude Code, but have CLAUDE_CODE_USE_BEDROCK=1 set in ~/.claude/settings.json, Claude Code routes requests to AWS Bedrock instead of Ollama. Bedrock rejects the local model name (e.g., 'gemma4') with a 400 error. This is a subtle configuration conflict that's hard to diagnose without knowing both tools' settings interactions.

Is the API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name guidance source-backed?

The "Ollama Launch Claude Fails with API Error 400 When CLAUDE_CODE_USE_BEDROCK Is Set" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name?

For "Ollama Launch Claude Fails with API Error 400 When CLAUDE_CODE_USE_BEDROCK Is Set", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging API Error (model_name): 400 Bad Request — Bedrock rejects Ollama model name?

For "Ollama Launch Claude Fails with API Error 400 When CLAUDE_CODE_USE_BEDROCK Is Set", collect the failing Ollama command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.