_Disclaimer: produced mostly by Claude Opus 4.6 following detailed
planning._
## Summary
- Support multiple instances of the same AI Bridge provider type via
indexed env vars (`CODER_AIBRIDGE_PROVIDER_<N>_<KEY>`), following the
`CODER_EXTERNAL_AUTH_<N>_<KEY>` pattern
- Existing single-provider env vars (`CODER_AIBRIDGE_OPENAI_KEY`, etc.)
continue to work unchanged
- Setting both a legacy env var and an indexed provider with the same
name errors at startup to prevent silent misconfiguration
- Mark legacy provider fields (`OpenAI`, `Anthropic`, `Bedrock`) as
deprecated in `AIBridgeConfig` in favor of `Providers`
## Example
```sh
CODER_AIBRIDGE_PROVIDER_0_TYPE=anthropic
CODER_AIBRIDGE_PROVIDER_0_NAME=anthropic-corp
CODER_AIBRIDGE_PROVIDER_0_KEY=sk-ant-corp-xxx
CODER_AIBRIDGE_PROVIDER_0_BASE_URL=https://llm-proxy.internal.example.com/anthropic
CODER_AIBRIDGE_PROVIDER_1_TYPE=anthropic
CODER_AIBRIDGE_PROVIDER_1_NAME=anthropic-direct
CODER_AIBRIDGE_PROVIDER_1_KEY=sk-ant-direct-yyy
```
Each instance is routed by name:
- /api/v2/aibridge/**anthropic-corp**/v1/messages
- /api/v2/aibridge/**anthropic-direct**/v1/messages
Closes
[AIGOV-157](https://linear.app/codercom/issue/AIGOV-157/spike-to-understand-if-there-is-a-simple-way-to-handle-multi-api-key)
---------
Signed-off-by: Danny Kopping <danny@coder.com>
## Description
Blocks `CONNECT` tunnels to private and reserved IP ranges in
aibridgeproxyd, preventing the proxy from being used to reach internal
networks.
The Coder access URL is always exempt (hostname+port match) so the proxy
can reach its own deployment. It is possible to exempt additional ranges
via `CODER_AIBRIDGE_PROXY_ALLOWED_PRIVATE_CIDRS`.
DNS rebinding is handled differently per path:
* Direct (no upstream proxy): validate the resolved IP right before the
TCP dial, no window between check and connect.
* Upstream proxy: Resolves and checks before forwarding to the upstream
dialer. A small rebinding window exists since the upstream proxy
re-resolves independently.
## Changes
* Add blocked IP denylist covering private, reserved, and
special-purpose ranges
* Add `AllowedPrivateCIDRs` option with CLI flag and env var
* Wire IP checks into `proxy.ConnectDial` for both upstream and direct
paths
* Add tests for blocked/allowed cases across direct dial, upstream
proxy, CIDR exemptions, and CoderAccessURL exemption
Notes: documentation will be handled in a follow-up PR.
Closes: https://github.com/coder/security/issues/124
## Description
Adds optional TLS support for the AI Bridge Proxy listener. When TLS cert and key files are provided, the proxy serves over HTTPS instead of plain HTTP.
## Changes
* New configuration options to enable TLS on the proxy listener
* Wraps the TCP listener in `tls.NewListener` when configured
* Tests for validation errors, invalid files, and full integration (tunneled + MITM) through a TLS listener
Note: Documentation for TLS listener setup and client configuration will be handled in a follow-up PR.
Related to: https://github.com/coder/internal/issues/1335
## Description
Renames internal fields, variables, and comments related to the proxy's certificate/key configuration to explicitly reference their MITM CA purpose.
The AI Bridge Proxy uses a CA certificate to sign dynamically generated leaf certificates during MITM interception of HTTPS traffic from AI clients. With the upcoming introduction of TLS listener certificates (for serving the proxy itself over HTTPS, implemented upstack https://github.com/coder/coder/pull/22411), the previous generic naming would become ambiguous. This refactor makes it clear which certificate is which.
No user-facing flags, environment variables, YAML keys, or JSON fields were changed, this is purely an internal rename to avoid confusion going forward.
Related to https://github.com/coder/internal/issues/1335
## Description
Adds Prometheus metrics to the AI Bridge Proxy for observability into
proxy traffic and performance.
## Changes
* Add Metrics struct with the following metrics:
* `connect_sessions_total`: counts CONNECT sessions by type
(mitm/tunneled)
* `mitm_requests_total`: counts MITM requests by provider
* `inflight_mitm_requests`: gauge tracking in-flight requests by
provider
* `mitm_request_duration_seconds`: histogram of request latencies by
provider
* `mitm_responses_total`: counts responses by status code class
(2XX/3XX/4XX/5XX) and provider
* Register metrics with `coder_aibridgeproxyd_` prefix in CLI
* Unregister metrics on server close to prevent registry leaks
* Add `tunneledMiddleware` to track non-allowlisted CONNECT sessions
* Add tests for metric recording in both MITM and tunneled paths
Closes: https://github.com/coder/internal/issues/1185
## Description
Adds upstream proxy support for AI Bridge Proxy passthrough requests.
This allows aiproxy to forward non-allowlisted requests through an
upstream proxy. Currently, the only supported configuration is when
aiproxy is the first proxy in the chain (client → aiproxy → upstream
proxy).
## Changes
* Add `--aibridge-proxy-upstream` option to configure an upstream
HTTP/HTTPS proxy URL for passthrough requests
* Add `--aibridge-proxy-upstream-ca` option to trust custom CA
certificates for HTTPS upstream proxies
* Passthrough requests (non-allowlisted domains) are forwarded through
the upstream proxy
* MITM'd requests (allowlisted domains) continue to go directly to
aibridge, not through the upstream proxy
* Add tests for upstream proxy configuration and request routing
Closes: https://github.com/coder/internal/issues/1204
## Description
Implements selective MITM (Man-in-the-Middle) in `aibridgeproxyd` so
that only requests to allowlisted domains are intercepted and decrypted.
Requests to all other domains are tunneled directly without decryption.
## Changes
* New config option: `CODER_AIBRIDGE_PROXY_DOMAIN_ALLOWLIST` (default:
`api.anthropic.com`,`api.openai.com`)
* Selective MITM: Uses `goproxy.ReqHostIs()` to only intercept `CONNECT`
requests to allowlisted hosts
* Certificate caching: Now only generates/caches certificates for
allowlisted domains
* Validation: Startup fails if domain allowlist is empty or contains
invalid entries
Closes: https://github.com/coder/internal/issues/1182
## Description
Implements request routing for the AI Bridge Proxy. After MITM decryption, requests to known AI providers (Anthropic, OpenAI) are rewritten to the corresponding aibridged endpoint, while requests to unknown hosts are passed through to their original destination.
## Changes
* Add `CoderAccessURL` configuration option for specifying the Coder deployment URL
* Add `handleRequest` to route decrypted requests based on target host
* Route known AI providers (Anthropic and OpenAI) to AI Bridge specific endpoint.
* Passthrough requests to unknown hosts directly to their original destination
* Inject Coder session token (from https://github.com/coder/coder/pull/21342) as `Authorization: Bearer` header for aibridged
* Add tests for routing and passthrough behavior
Depends on: https://github.com/coder/coder/pull/21342
Closes: https://github.com/coder/internal/issues/1181
## Description
Adds the core AI Bridge MITM proxy daemon. This proxy intercepts HTTPS traffic, decrypts it using a configured CA certificate, and forwards requests to AIBridge for processing.
## Changes
* Added `aibridgeproxyd` package with the core proxy server implementation
* Added configuration options: `CODER_AIBRIDGE_PROXY_ENABLED`, `CODER_AIBRIDGE_PROXY_LISTEN_ADDR`, `CODER_AIBRIDGE_PROXY_CERT_FILE`, `CODER_AIBRIDGE_PROXY_KEY_FILE`
* Added tests for server initialization and MITM functionality
Closes https://github.com/coder/internal/issues/1180
Danny Kopping