AGENTS.md

1# Call Credentials
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3This directory defines the `grpc_call_credentials` interface, which is used to add per-call security information to a gRPC call.
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5## Overarching Purpose
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7Call credentials are used to attach security information to individual gRPC calls. This can be used for things like OAuth 2.0 access tokens, which need to be refreshed periodically.
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9## Files
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11- **`call_creds_util.h` / `call_creds_util.cc`**: Utilities for working with call credentials.
12- **`composite_call_credentials.h` / `composite_call_credentials.cc`**: A call credential that is composed of multiple other call credentials.
13- **`context_authenticator.h`**: A `grpc_auth_context` that is populated from call credentials.
14- **`credentials.h`**: The base `grpc_credentials` class.
15- **`fake_credentials.h`**: A fake implementation of call credentials for testing.
16- **`jwt_credentials.h` / `jwt_credentials.cc`**: An implementation of call credentials that uses JWTs.
17- **`oauth2_credentials.h` / `oauth2_credentials.cc`**: An implementation of call credentials that uses OAuth 2.0.
18- **`plugin_credentials.h` / `plugin_credentials.cc`**: An implementation of call credentials that uses a plugin.
19- **`sts_credentials.h` / `sts_credentials.cc`**: An implementation of call credentials that uses STS.
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21## Notes
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23- Call credentials are a powerful tool for adding per-call security to gRPC.
24- They are often used in conjunction with channel credentials to provide a complete security solution.
25- The `grpc_call_credentials` interface is designed to be extensible, allowing new call credential types to be added easily.
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