fix(api-server): add CORS headers to streaming SSE responses by teknium1 · Pull Request #3573 · NousResearch/hermes-agent

teknium1 · 2026-03-28T20:34:55Z

Summary

The CORS middleware adds headers after the handler returns, but StreamResponse flushes headers on prepare() — so SSE streaming responses were missing all CORS headers. Browser clients hitting the streaming endpoint from a different origin would get blocked.

Improved over #3381's approach: instead of spreading the static _CORS_HEADERS (which lacks Access-Control-Allow-Origin), this calls _cors_headers_for_origin() to resolve the full dynamic CORS header set including the origin.

Salvaged from #3381 by @ygd58 with authorship preserved.

Changes

gateway/platforms/api_server.py: resolve CORS headers before prepare() on the SSE StreamResponse

Test plan

python -m pytest tests/gateway/test_api_server.py -n0 -q  # 86 passed

StreamResponse headers are flushed on prepare() before the CORS middleware can inject them. Resolve CORS headers up front using _cors_headers_for_origin() so the full set (including Access-Control-Allow-Origin) is present on SSE streams. Co-authored-by: ygd58 <ygd58@users.noreply.github.com>

… pages Fixes found by auditing docs against recent PRs/commits: Critical (misleading): - hooks.md: Remove stale 'planned — not yet wired' markers for 4 hooks that are now active (#3542). Add correct callback signatures. - security.md: Update tirith verdict behavior — block verdicts now go through approval flow instead of hard-blocking (#3428). Add pkill/killall self-termination guard and gateway-run backgrounding patterns (#3593). New feature docs: - configuration.md: Add tool_use_enforcement section with value table (auto/true/false/list) from #3551/#3528. - configuration.md: Expand auxiliary config with per-task timeouts (compression 120s, web_extract 30s, approval 30s) from #3597. - api-server.md: Add /v1/health alias, Security Headers section, CORS details (Max-Age, SSE headers, Idempotency-Key) from #3572/#3573/#3576/#3580/#3530. Stale/incomplete: - configuration.md: Fix Alibaba model name qwen-plus -> qwen3.5-plus (#3484). - environment-variables.md: Specify actual DashScope default URL. - cli-commands.md: Add alibaba to --provider list. - fallback-providers.md: Add Alibaba/DashScope to provider table. - email.md: Document noreply/automated sender filtering (#3606). - toolsets-reference.md: Add 4 missing platform toolsets — matrix, mattermost, dingtalk, api-server (#3583). - skills.md: List default GitHub taps including garrytan/gstack (#3605).

… pages (#3618) Fixes found by auditing docs against recent PRs/commits: Critical (misleading): - hooks.md: Remove stale 'planned — not yet wired' markers for 4 hooks that are now active (#3542). Add correct callback signatures. - security.md: Update tirith verdict behavior — block verdicts now go through approval flow instead of hard-blocking (#3428). Add pkill/killall self-termination guard and gateway-run backgrounding patterns (#3593). New feature docs: - configuration.md: Add tool_use_enforcement section with value table (auto/true/false/list) from #3551/#3528. - configuration.md: Expand auxiliary config with per-task timeouts (compression 120s, web_extract 30s, approval 30s) from #3597. - api-server.md: Add /v1/health alias, Security Headers section, CORS details (Max-Age, SSE headers, Idempotency-Key) from #3572/#3573/#3576/#3580/#3530. Stale/incomplete: - configuration.md: Fix Alibaba model name qwen-plus -> qwen3.5-plus (#3484). - environment-variables.md: Specify actual DashScope default URL. - cli-commands.md: Add alibaba to --provider list. - fallback-providers.md: Add Alibaba/DashScope to provider table. - email.md: Document noreply/automated sender filtering (#3606). - toolsets-reference.md: Add 4 missing platform toolsets — matrix, mattermost, dingtalk, api-server (#3583). - skills.md: List default GitHub taps including garrytan/gstack (#3605).

…earch#3573) StreamResponse headers are flushed on prepare() before the CORS middleware can inject them. Resolve CORS headers up front using _cors_headers_for_origin() so the full set (including Access-Control-Allow-Origin) is present on SSE streams. Co-authored-by: ygd58 <ygd58@users.noreply.github.com>

… pages (NousResearch#3618) Fixes found by auditing docs against recent PRs/commits: Critical (misleading): - hooks.md: Remove stale 'planned — not yet wired' markers for 4 hooks that are now active (NousResearch#3542). Add correct callback signatures. - security.md: Update tirith verdict behavior — block verdicts now go through approval flow instead of hard-blocking (NousResearch#3428). Add pkill/killall self-termination guard and gateway-run backgrounding patterns (NousResearch#3593). New feature docs: - configuration.md: Add tool_use_enforcement section with value table (auto/true/false/list) from NousResearch#3551/NousResearch#3528. - configuration.md: Expand auxiliary config with per-task timeouts (compression 120s, web_extract 30s, approval 30s) from NousResearch#3597. - api-server.md: Add /v1/health alias, Security Headers section, CORS details (Max-Age, SSE headers, Idempotency-Key) from NousResearch#3572/NousResearch#3573/NousResearch#3576/NousResearch#3580/NousResearch#3530. Stale/incomplete: - configuration.md: Fix Alibaba model name qwen-plus -> qwen3.5-plus (NousResearch#3484). - environment-variables.md: Specify actual DashScope default URL. - cli-commands.md: Add alibaba to --provider list. - fallback-providers.md: Add Alibaba/DashScope to provider table. - email.md: Document noreply/automated sender filtering (NousResearch#3606). - toolsets-reference.md: Add 4 missing platform toolsets — matrix, mattermost, dingtalk, api-server (NousResearch#3583). - skills.md: List default GitHub taps including garrytan/gstack (NousResearch#3605).