The symptom pattern: partial AWS success with stubborn timeouts

You already run Clash daily. Pages like the AWS Management Console load when you flip system proxy on. Maybe even the Bedrock playground responds quickly in Chrome. Then you attach AWS Agent Toolkit inside your IDE, invoke an agent that streams tokens from Amazon Bedrock, or run a local harness that calls bedrock-runtime, and the UI freezes around long-running HTTP requests. Logs mention read timeouts, connection resets, or nondescript SDK retries. Switching nodes blindly sometimes helps for a minute, which feels like proof that “the proxy is flaky,” but the underlying issue is usually simpler: not every hostname your toolchain touches shares the same routing decision.

Bedrock workloads are especially sensitive because model inference rides HTTPS to regional endpoints such as bedrock-runtime.<region>.amazonaws.com. Credential acquisition may bounce through sts.amazonaws.com or regional STS variants. Browser SSO flows can introduce extra hosts under *.awsapps.com or sign-in domains. If any one of those legs leaves your machine without hitting the proxy listener you expect, or lands in a policy group tuned for casual browsing rather than stable TLS to US-East or Tokyo regions, you observe exactly the intermittent API timeouts that send developers hunting for new upstream subscriptions.

This article assumes you are authorized to use AWS services from your network path and that your IAM policies already grant Bedrock access. We focus on transport: how to align Clash rules with the actual hostnames modern AWS agent tooling uses, how to present the proxy to JVM-based IDEs and terminals, and how to validate outcomes without guessing.

Why AWS Agent Toolkit traffic is not “one hostname and done”

Compared with pinning a single SaaS API, AWS spreads responsibilities across multiple vertically integrated endpoints. Amazon Bedrock runtime calls are only the headline. Underneath, the AWS SDK refreshes credentials through STS. Feature discovery might query service endpoints maintained in partitioned DNS trees. Some IDE integrations bundle telemetry or marketplace checks that reuse generic AWS networks. If your profile only contains a catch-all AI bucket modeled after split routing for ChatGPT-style sites, Bedrock traffic might still miss that bucket entirely because AWS domains do not resemble consumer AI brands.

The AWS Agent Toolkit ecosystem compounds the challenge because it orchestrates multiple subprocesses. The IDE plugin, language servers, and bundled CLI helpers do not automatically inherit macOS network extension settings the way Safari does. On Windows, WinInet-aware binaries behave differently from Node-driven assistants spawned by editors. Without explicit environment variables or transparent interception, each subprocess may choose DIRECT egress independently, which breaks optimization heuristics inside the AWS SDK that assume a stable latency profile.

Finally, geography shortcuts matter. Profiles tuned for mainland performance frequently hoist GEOIP,CN,DIRECT or imported rule-sets that classify cloud IP ranges aggressively. AWS edge and Bedrock front-ends live on global anycast networks; some addresses may match broad rules you never intended for API traffic. Explicit domain exceptions remain the dependable fix.

Domains and patterns worth pinning for Bedrock and toolkit flows

Start from what Bedrock itself documents: inference and guardrail calls target regional HTTPS hosts following bedrock-runtime.<region>.amazonaws.com. Management actions such as listing foundation models may use bedrock.<region>.amazonaws.com. If you operate cross-region fallbacks, enumerate each region you actually configure rather than relying on wild guesses.

Shared credential plumbing almost always touches sts.amazonaws.com plus regional STS endpoints shaped like sts.<region>.amazonaws.com. Temporary keys retrieved through IAM Roles Anywhere or SSO may add hosts such as *.sso.amazonaws.com or your organization’s AWS IAM Identity Center portal domain. When browser SSO works but IDE tokens never refresh, inspect whether those sign-in hosts share the same proxy group as Bedrock runtime traffic.

Optional but common companions include CloudWatch Logs endpoints when agents emit structured telemetry, S3 buckets referenced by prompt repositories, and Secrets Manager hostnames if your toolkit pulls configuration from managed secrets. Add them only when packet captures or connection logs prove they participate in the failing workflow; overshooting with a blunt DOMAIN-SUFFIX,amazonaws.com route drags unrelated workloads through an international exit and can confuse latency-sensitive domestic APIs.

For teams combining Bedrock with OpenAI-compatible gateways or third-party assistants, keep those vendors in separate groups so experimentation does not poison production AWS routing. The architectural pattern matches what we described for Claude Code and Anthropic API split routing: one named lane per provider family, ordered ahead of geography shortcuts.

Designing an AWS-BEDROCK policy group in Clash

Create a dedicated proxy group—call it AWS-BEDROCK or AWS-API—rather than reusing a generic Proxy bucket shared with streaming video traffic. A select group is adequate when you manually choose exits. A url-test group shines when you want periodic measurements against a stable HTTPS host such as https://sts.amazonaws.com; tune intervals so health checks do not hammer STS during quiet periods.

Inside the group list both your preferred relay nodes and, if policy permits, DIRECT as an explicit fallback. Keeping DIRECT visible forces conscious choices when an upstream blocks AWS temporarily; hiding it behind implicit defaults makes troubleshooting harder because logs no longer show intentional domestic breaks.

If latency to Bedrock in us-west-2 differs materially from us-east-1, duplicate narrow regional rules rather than relying on one overloaded node across continents. Some organizations enforce data residency; documenting which regions belong in AWS-BEDROCK prevents accidental cross-border hops.

A minimal YAML skeleton compatible with mihomo cores looks like this:

proxy-groups:
  - name: AWS-BEDROCK
    type: select
    proxies:
      - <stable exit node>
      - DIRECT

rules:
  - DOMAIN-KEYWORD,bedrock-runtime,AWS-BEDROCK
  - DOMAIN-KEYWORD,bedrock.,AWS-BEDROCK
  - DOMAIN,sts.amazonaws.com,AWS-BEDROCK
  # Optional explicit regions:
  # - DOMAIN,bedrock-runtime.us-east-1.amazonaws.com,AWS-BEDROCK
  # ... remaining rules follow

Adjust keyword rules carefully: DOMAIN-KEYWORD matches anywhere in the hostname, which is powerful but easy to overmatch if unrelated assets contain the substring bedrock. When precision matters, prefer explicit DOMAIN lines per region.

Rule order: beat GEOIP and imported AI lists

Clash evaluates rules sequentially and stops at the first hit. Community bundles marketed as “AI routing” rarely include the intersection of Bedrock hosts your toolkit uses. Even when they do, the bundled destination group might differ from the stable exit you want for regulated workloads.

Place your AWS-focused domain rules above:

• Broad GEOIP shortcuts that send ambiguous ranges domestic.
• Imported RULE-SET rows that classify AWS IP space unexpectedly.
• Catch-all MATCH entries pointing at generic international proxies tuned for HTTP browsing throughput rather than long-lived HTTPS streams.

If you must shadow an upstream rule-set entry, insert a more specific DOMAIN rule above the set reference rather than forking the entire remote file. Document the rationale inline so the next profile refresh does not quietly reorder sections.

For mental models about Fake-IP interactions and evaluation order, revisit Clash YAML: routing rules, proxy groups, and Fake-IP; the guidance applies unchanged when AWS endpoints sit behind modern resolver setups.

Exposing the proxy to IDEs, terminals, and language SDKs

Correct rules still fail when processes never reach your mixed port. VS Code, JetBrains IDEs, and standalone Python virtual environments inherit environment variables from their parent shell. macOS terminals opened before Clash starts often lack HTTP_PROXY. Windows PowerShell sessions resemble that story; WSL2 adds yet another hop, solved separately through routing WSL2 Ubuntu traffic through the Windows Clash mixed port.

The portable baseline exports both uppercase and lowercase proxy variables:

export HTTP_PROXY="http://127.0.0.1:7890"
export HTTPS_PROXY="http://127.0.0.1:7890"
export NO_PROXY="localhost,127.0.0.1,::1,169.254.169.254"

Replace 7890 with your GUI-reported mixed port. Keep 169.254.169.254 on NO_PROXY when workloads must reach link-local metadata services without looping through Clash. JVM-based tooling respects these variables when launched from a shell that already sourced them; launching the IDE from Finder or Start Menu bypasses that context unless you set proxy preferences inside the IDE itself.

AWS-specific tooling sometimes honors AWS_CA_BUNDLE or custom trust stores when intercepting proxies exist in enterprise environments. If TLS succeeds via curl but fails inside Java, investigate certificate pinning rather than routing alone.

TUN mode when you want transparent routing

TUN forwards packets beneath application awareness, which eliminates per-shell proxy exports when configured cleanly. Agent subprocesses inherit the same routing table entries as browsers, so Bedrock streams receive identical treatment as long as rules match before bypass directives.

Tradeoffs include elevated privileges and occasional conflicts with corporate VPN clients or virtualization stacks. On Windows, review Clash TUN routing and firewall fixes before blaming Bedrock for silent drops.

Whether you choose explicit proxies or TUN, keep the AWS domain rules identical; only the injection mechanism changes.

DNS, Fake-IP, and regional resolution pitfalls

Inconsistent DNS yields spooky symptoms: the SDK resolves a Bedrock endpoint to an unexpected address, your rules fail to match by domain, and connections appear as raw IPs classified by GEOIP. Confirm that Bedrock hostnames are not mistakenly listed in fake-ip-filter unless you understand the consequence of skipping synthetic responses.

Dual-stack environments occasionally resolve IPv6 first while your proxy listener only accepts IPv4 forwards. If logs show IPv6 attempts stalling, align resolver preferences or disable IPv6 for testing.

When domestic DNS servers rewrite AWS answers differently than public resolvers, capture comparisons using dig against both paths. Alignment matters more than raw latency.

Verification playbook: logs, curl, and SDK probes

Open your Clash dashboard connection log and reproduce the failing agent action. You should see each HTTPS dial associate with AWS-BEDROCK or whichever group you named. If entries show DIRECT while rules exist, scroll upward: something matched earlier with higher priority.

Use curl with an explicit proxy to isolate TLS from SDK complexity:

curl -v --proxy http://127.0.0.1:7890 https://sts.amazonaws.com/ 2>&1 | head -40

Expect HTTP responses such as 404 or concise XML errors from STS when unauthenticated; the valuable signal is a completed TLS handshake. Failures before TLS indicate proxy ports, certificates, or firewall paths rather than IAM.

For Bedrock-specific paths, substitute your regional runtime hostname once you confirm DNS resolves correctly:

curl -v --proxy http://127.0.0.1:7890 https://bedrock-runtime.us-east-1.amazonaws.com/ 2>&1 | head -40

If curl succeeds while the toolkit fails, dump effective proxy variables inside the IDE terminal emulator (env | grep -i proxy). Missing variables confirm an environment inheritance bug rather than Bedrock downtime.

Symptom matrix for Bedrock and toolkit outages

Adjacent developer routing: keep Cursor and containers separate

Teams adopting Bedrock alongside GitHub Copilot competitors frequently run Cursor IDE split routing plus AWS lanes simultaneously. Treat each vendor stack as its own policy group to prevent latency optimizations meant for chat completions from de-prioritizing streaming Bedrock responses.

Containerized agents should reuse host proxy settings via service-level environment injection rather than baking secrets into images. For Docker registry friction unrelated to Bedrock, see Docker registry split routing.

Frequently asked questions

Does a blanket amazonaws.com rule simplify maintenance?

It centralizes configuration but couples unrelated workloads. Domestic teams relying on AWS China partitions or corporate endpoints inside intranets may break subtle assumptions. Prefer explicit Bedrock and STS hosts, expanding only when logs reveal gaps.

What about mixing OpenAI and Bedrock in one agent?

Orchestrators that fan out to multiple providers need distinct domain clusters per vendor. Combined routing groups obscure logs and make failover unpredictable when only one backend degrades.

SSO works in Safari but tokens never appear in the toolkit

Verify both browser SSO domains and STS endpoints share consistent exits. Split tunnel VPNs sometimes route browsers through corporate inspection while IDEs remain local-direct, producing mismatched sessions.

Closing: predictable lanes tame Agent Toolkit timeouts

AWS Agent Toolkit and Amazon Bedrock amplify productivity when every HTTPS leg shares a coherent policy decision. The frustrating part is not cryptography or model physics but mundane routing: a missing domain row here, a shell without proxy exports there, and suddenly every symptom masquerades as an API timeout.

Compared with opaque clients that hide path selection, Clash-family cores expose the exact rule match and node choice behind each connection. That transparency converts mysterious thirty-second hangs into actionable edits in your split routing rules. When you want polished GUIs atop those diagnostics, start from the download page and align your client with the YAML patterns above. For a direct install link in closing context, you can also download Clash for free and wire Bedrock traffic with confidence.