[TOGEP]

Summary

Changes

Add AWS_MCP_PROXY_PROFILE_REGEX to select locally configured AWS profiles using a regular expression.

Matching profiles are added to the explicitly configured profile list at startup, with duplicates removed. The explicit profile order, default profile, and existing configuration precedence are preserved.

Closes #447.

User experience

Previously, users had to list every profile explicitly and update the list whenever profiles were added or removed.

Users can now specify a default profile and automatically include additional profiles based on a naming pattern:

export AWS_MCP_PROXY_PROFILES="dev-ReadOnlyAccess"
export AWS_MCP_PROXY_PROFILE_REGEX=".*-ReadOnlyAccess$"

The regex is matched against entire profile names. Matching profiles become available for per-call switching, while the explicitly configured profile remains the default.

Profile changes take effect after restarting the proxy.

Checklist

If your change doesn't seem to apply, please leave them unchecked.

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? (Y/N)

• Yes
• No

Validation

❯ .venv/bin/pytest tests/unit/test_server.py -q --log-cli-level=ERROR --tb=short

tests/unit/test_server.py::TestServer::test_setup_mcp_mode PASSED                                                                                   [  2%]
tests/unit/test_server.py::TestServer::test_setup_mcp_mode_no_retries PASSED                                                                        [  5%]
tests/unit/test_server.py::TestServer::test_setup_mcp_mode_no_metadata_injects_aws_region PASSED                                                    [  8%]
tests/unit/test_server.py::TestServer::test_setup_mcp_mode_metadata_without_aws_region_injects_it PASSED                                            [ 11%]
tests/unit/test_server.py::TestServer::test_add_tool_filtering_middleware PASSED                                                                    [ 13%]
tests/unit/test_server.py::TestServer::test_add_retry_middleware PASSED                                                                             [ 16%]
tests/unit/test_server.py::TestServer::test_parse_args_default PASSED                                                                               [ 19%]
tests/unit/test_server.py::TestServer::test_parse_args_custom PASSED                                                                                [ 22%]
tests/unit/test_server.py::TestServer::test_main_function PASSED                                                                                    [ 25%]
tests/unit/test_server.py::TestServer::test_main_error_handling PASSED                                                                              [ 27%]
tests/unit/test_server.py::TestServer::test_validate_service_name_service_parsing PASSED                                                            [ 30%]
tests/unit/test_server.py::TestServer::test_create_sigv4_client PASSED                                                                              [ 33%]
tests/unit/test_server.py::TestServer::test_create_sigv4_client_no_credentials PASSED                                                               [ 36%]
tests/unit/test_server.py::TestServer::test_main_module_execution PASSED                                                                            [ 38%]
tests/unit/test_server.py::TestProfileDedup::test_duplicate_profiles_are_deduped PASSED                                                             [ 41%]
tests/unit/test_server.py::TestProfileDedup::test_default_profile_included_in_allowed_list PASSED                                                   [ 44%]
tests/unit/test_server.py::TestProfileDedup::test_single_profile_no_middleware PASSED                                                               [ 47%]
tests/unit/test_server.py::TestRegexProfiles::test_profile_selection[preserves-default-and-explicit-order] PASSED                                   [ 50%]
tests/unit/test_server.py::TestRegexProfiles::test_profile_selection[full-name-match] PASSED                                                        [ 52%]
tests/unit/test_server.py::TestRegexProfiles::test_profile_selection[deduplication] PASSED                                                          [ 55%]
tests/unit/test_server.py::TestRegexProfiles::test_profile_selection[default-only] PASSED                                                           [ 58%]
tests/unit/test_server.py::TestRegexProfiles::test_explicit_default_overrides_missing_aws_profile[None-env] PASSED                                  [ 61%]
tests/unit/test_server.py::TestRegexProfiles::test_explicit_default_overrides_missing_aws_profile[None-cli] PASSED                                  [ 63%]
tests/unit/test_server.py::TestRegexProfiles::test_explicit_default_overrides_missing_aws_profile[deleted-profile-env] PASSED                       [ 66%]
tests/unit/test_server.py::TestRegexProfiles::test_explicit_default_overrides_missing_aws_profile[deleted-profile-cli] PASSED                       [ 69%]
tests/unit/test_server.py::TestRegexProfiles::test_no_regex_does_not_load_profiles[None] PASSED                                                     [ 72%]
tests/unit/test_server.py::TestRegexProfiles::test_no_regex_does_not_load_profiles[] PASSED                                                         [ 75%]
tests/unit/test_server.py::TestRegexProfiles::test_configuration_errors[[-profiles0-Invalid AWS_MCP_PROXY_PROFILE_REGEX] PASSED                     [ 77%]
tests/unit/test_server.py::TestRegexProfiles::test_configuration_errors[.*-None-requires an explicit default profile] PASSED                        [ 80%]
tests/unit/test_server.py::TestRegexProfiles::test_configuration_errors[missing-.*-profiles2-did not match any available AWS profiles] PASSED       [ 83%]
tests/unit/test_server.py::TestEnvVarProfiles::test_env_var_parsed_when_no_profile_flag PASSED                                                      [ 86%]
tests/unit/test_server.py::TestEnvVarProfiles::test_env_var_takes_precedence_over_profile_flag PASSED                                               [ 88%]
tests/unit/test_server.py::TestEnvVarProfiles::test_empty_env_var_ignored PASSED                                                                    [ 91%]
tests/unit/test_server.py::TestEnvVarProfiles::test_env_var_handles_extra_whitespace PASSED                                                         [ 94%]
tests/unit/test_server.py::TestFix2EnvVarPrecedence::test_env_var_profiles_wins_over_aws_profile PASSED                                             [ 97%]
tests/unit/test_server.py::TestEnvVarActivatesMiddleware::test_env_var_activates_profile_middleware PASSED                                          [100%]

=================================================================== 36 passed in 0.55s ====================================================================

Acknowledgment

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