Aider error
Aider: You need to: pip install boto3
You need to: pip install boto3Status: WorkaroundLast verified 4 documented fixes3 sources
What it means
You picked an AWS Bedrock model, but the boto3 package is not installed in aider's Python environment. Aider detects "boto3" in the litellm APIConnectionError and stops without retrying.
Causes
- boto3 is not installed in the environment aider runs in; the Bedrock docs say you may need to install it.
How to fix it
- Fix 1.
If you installed with aider-install or uv tool:
Snippetuv tool run --from aider-chat pip install boto3 - Fix 2.
If you installed with pipx:
Snippetpipx inject aider-chat boto3 - Fix 3.
Otherwise:
Terminalpip install -U boto3 - Fix 4.
The full docker container includes boto3 for Bedrock since v0.74.0.
More Aider errors
All 17 Aider errorsThe LLM did not conform to the edit format.Status: WorkaroundSearchReplaceNoExactMatch: This SEARCH block failed to exactly match lines in {path}Status: WorkaroundModel gpt-3.5-turbo has hit a token limit!Status: WorkaroundModel foobar: Unknown context window size and costs, using sane defaults.Status: By designModel azure/gpt-4-turbo: Missing these environment variables:Status: By designaider: The term 'aider' is not recognized as a name of a cmdlet, function, script file, or executable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.Status: Workaroundaider-chat 0.23.0 requires somepackage==X.Y.Z, but you have somepackage U.W.V which is incompatible.Status: WorkaroundThe API provider is not able to authenticate you. Check your API key.Status: By design
Related reading
- Aider vs Claude Code in 2026: Git-First Open Source vs Subagent RuntimeAider vs Claude Code: git-first, model-agnostic Aider against the Claude Code runtime of subagents and hooks. Compare architecture, cost, governance and fit.
- Aider vs Claude Code: Open Source vs Commercial AI Coding CLIAider is open source and works with any model. Claude Code is Anthropic's commercial agent. Here is how they compare for TypeScript.
FAQ
What does "You need to: pip install boto3" mean in Aider?
You picked an AWS Bedrock model, but the boto3 package is not installed in aider's Python environment. Aider detects "boto3" in the litellm APIConnectionError and stops without retrying.
How do I fix "You need to: pip install boto3"?
There are 4 documented fixes. Start with the first: If you installed with aider-install or uv tool:
Is this Aider error fixed?
Status: Workaround. No release removes the cause. The documented fixes work around it. Affected versions: All versions using Bedrock without boto3; full docker image bundles boto3 since v0.74.0.
Sources
Last verified against 3 sources: official docs, maintainer replies and release notes.
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