## Why
First-party async traits should expose their `Send` contracts explicitly
without requiring `async_trait`. This completes the migration pattern
established in #27303 and #27304.
## What changed
- Replaced the remaining first-party `async_trait` traits with native
return-position `impl Future + Send` where statically dispatched and
explicit boxed `Send` futures where object safety is required.
- Kept implementations behavior-preserving, outlining existing async
bodies into inherent methods where that keeps the diff reviewable.
- Removed all direct first-party `async-trait` dependencies and the
workspace dependency declaration.
- Added a cargo-deny policy that permits `async-trait` only through the
remaining transitive wrapper crates.
- Updated `rand` from 0.8.5 to 0.8.6 to resolve RUSTSEC-2026-0097 and
keep the full cargo-deny check passing.
## Validation
- `just test -p codex-exec-server`: 216 passed, 2 skipped.
- `just test -p codex-model-provider`: 39 passed.
- `just test -p codex-core` and `just test`: changed tests passed;
remaining failures are environment-sensitive suites unrelated to this
migration.
- `cargo deny check`
- `just fix`
- `just fmt`
- `cargo shear`
- `just bazel-lock-check`
## Why
The Amazon Bedrock model provider currently discards the shared
`AuthManager`, so a Codex-managed Bedrock API key cannot reach
request-time provider auth. Bedrock instead falls through to AWS
environment or SDK credentials, and the request endpoint can be resolved
from a different region than the managed credential.
Managed Bedrock login should control both the bearer credential and
Mantle region. Unrelated OpenAI or ChatGPT credentials must remain
isolated from Bedrock.
## What changed
- Pass the shared `AuthManager` into `AmazonBedrockModelProvider`.
- Select `CodexAuth::BedrockApiKey` before the existing
`AWS_BEARER_TOKEN_BEDROCK` and AWS SDK/SigV4 paths.
- Use the managed Bedrock auth region when resolving the Mantle
endpoint.
- Filter other `CodexAuth` variants so OpenAI and ChatGPT auth are not
exposed to Bedrock request auth or unauthorized recovery.
- Add focused coverage for provider construction, managed-auth
precedence, bearer headers, endpoint selection, and OpenAI-auth
isolation.
## Why
Users following the Amazon Bedrock API-key setup can export
`AWS_BEARER_TOKEN_BEDROCK` and `AWS_REGION`, but Codex's bearer-token
auth path only accepted `model_providers.amazon-bedrock.aws.region`.
That made the documented env-based setup fail with a missing-region
error even though the standard AWS region environment variable was
present.
## What Changed
- Updates Bedrock bearer-token region resolution to use
`model_providers.amazon-bedrock.aws.region` first, then fall back to
`AWS_REGION`, then `AWS_DEFAULT_REGION`.
- Updates the missing-region error to list all supported region sources.
- Adds focused coverage for config precedence, `AWS_REGION`,
`AWS_DEFAULT_REGION`, and the missing-region failure.
## Summary
Codex's Amazon Bedrock provider signs Mantle requests with SigV4 using
credentials resolved by the AWS SDK. That worked for standard AWS
profiles and environment credentials, but AWS CLI console-login profiles
created by `aws login` require the SDK's `credentials-login` feature to
resolve `login_session` credentials.
This change enables that credential provider so Bedrock can use AWS
console-login credentials through the existing provider-owned AWS auth
path.
While testing the console-login path, we also hit a Mantle-specific
SigV4 regression from the new split between `session_id` and
`thread_id`. Mantle does not preserve legacy OpenAI compatibility
headers that use `snake_case` before SigV4 verification, so signing
those headers can make the server reconstruct a different canonical
request. The Bedrock auth path now removes that header class before
signing, keeping preserved hyphenated Codex/AWS headers such as
`x-codex-turn-metadata` signed normally.
## Changes
- Enable `aws-config`'s `credentials-login` feature in
`codex-rs/aws-auth`.
- Add a compile-time regression test for
`aws_config::login::LoginCredentialsProvider`.
- Strip `snake_case` compatibility headers from Bedrock Mantle SigV4
requests before signing.
- Expand the Bedrock auth regression test to cover `session_id`,
`thread_id`, and future headers of the same shape.
- Refresh Cargo and Bazel lockfiles for the added `aws-sdk-signin`
dependency.
## Tests
- tested with `aws login` locally and verified that it works as
intended.
## Why
`/status` was showing the configured `ModelProviderInfo.base_url` for
Amazon Bedrock, which can be stale or misleading because the actual
Bedrock Mantle endpoint is derived at runtime from the resolved AWS
region. This made sessions report the wrong provider endpoint even
though requests used the correct runtime URL.
## What changed
- Added `ModelProvider::runtime_base_url()` so provider implementations
can expose the request-time base URL through the shared runtime provider
abstraction.
- Moved Bedrock region-to-Mantle URL resolution into
`amazon_bedrock::mantle::runtime_base_url()`, keeping region resolution
private to the Mantle module.
- Overrode `runtime_base_url()` for Amazon Bedrock so it returns the
resolved Mantle endpoint instead of the configured default.
- Resolved and cached the runtime provider base URL during TUI startup,
then used that cached value when rendering `/status`.
- Added status coverage that verifies Bedrock displays the runtime URL
and ignores the configured Bedrock `base_url` when they differ.
## Verification
model provider is resolved correctly in local build:
<img width="696" height="245" alt="Screenshot 2026-04-29 at 5 01 36 PM"
src="https://github.com/user-attachments/assets/a13c10a5-3720-41ab-8ace-3c4bc573f971"
/>
## Summary
The Bedrock Mantle SigV4 auth provider currently looks like it can
lazily load `AwsAuthContext`, but the provider is only constructed after
`resolve_auth_method` has already loaded that context. Because
`with_context` always pre-populates the `OnceCell`, the
`get_or_try_init` fallback is unused in normal operation and makes the
provider lifecycle harder to reason about.
This change removes that dead lazy-loading path and makes the actual
behavior explicit:
- `BedrockAuthMethod::AwsSdkAuth` carries only the resolved
`AwsAuthContext`.
- `BedrockMantleSigV4AuthProvider` stores the resolved context directly.
- request signing uses the stored context without going through
`OnceCell`.
The existing eager AWS auth resolution behavior is unchanged; this is a
simplification of the provider state, not a behavior change.
## Testing
- `cargo shear`
- `cargo test -p codex-model-provider`
- `just bazel-lock-check`
## Summary
Add first-class Amazon Bedrock Mantle provider support so Codex can keep
using its existing Responses API transport with OpenAI-compatible
AWS-hosted endpoints such as AOA/Mantle.
This is needed for the AWS launch path, where provider traffic should
authenticate with AWS credentials instead of OpenAI bearer credentials.
Requests are authenticated immediately before transport send, so SigV4
signs the final method, URL, headers, and body bytes that `reqwest` will
send.
## What Changed
- Added a new `codex-aws-auth` crate for loading AWS SDK config,
resolving credentials, and signing finalized HTTP requests with AWS
SigV4.
- Added a built-in `amazon-bedrock` provider that targets Bedrock Mantle
Responses endpoints, defaults to `us-east-1`, supports region/profile
overrides, disables WebSockets, and does not require OpenAI auth.
- Added Amazon Bedrock auth resolution in `codex-model-provider`: prefer
`AWS_BEARER_TOKEN_BEDROCK` when set, otherwise use AWS SDK credentials
and SigV4 signing.
- Added `AuthProvider::apply_auth` and `Request::prepare_body_for_send`
so request-signing providers can sign the exact outbound request after
JSON serialization/compression.
- Determine the region by taking the `aws.region` config first (required
for bearer token codepath), and fallback to SDK default region.
## Testing
Amazon Bedrock Mantle Responses paths:
- Built the local Codex binary with `cargo build`.
- Verified the custom proxy-backed `aws` provider using `env_key =
"AWS_BEARER_TOKEN_BEDROCK"` streamed raw `responses` output with
`response.output_text.delta`, `response.completed`, and `mantle-env-ok`.
- Verified a full `codex exec --profile aws` turn returned
`mantle-env-ok`.
- Confirmed the custom provider used the bearer env var, not AWS profile
auth: bogus `AWS_PROFILE` still passed, empty env var failed locally,
and malformed env var reached Mantle and failed with `401
invalid_api_key`.
- Verified built-in `amazon-bedrock` with `AWS_BEARER_TOKEN_BEDROCK` set
passed despite bogus AWS profiles, returning `amazon-bedrock-env-ok`.
- Verified built-in `amazon-bedrock` SDK/SigV4 auth passed with
`AWS_BEARER_TOKEN_BEDROCK` unset and temporary AWS session env
credentials, returning `amazon-bedrock-sdk-env-ok`.
Adam Perry @ OpenAI