docs(error-tracking): document ASP.NET Core exception capture

[cat-ph]

Problem

The .NET Error Tracking guide says automatic exception capture is unavailable and implements custom ASP.NET Core middleware. PostHog.AspNetCore 2.7.0 already ships opt-in request exception capture in its official request context middleware.

Exact released behavior

• PostHog.AspNetCore 2.7.0 and later expose UsePostHogRequestContext with PostHogRequestContextOptions.CaptureExceptions.
• CaptureExceptions defaults to false.
• When enabled, the middleware captures unhandled downstream ASP.NET Core request exceptions with the active request context and HTTP response status, then throws them again.
• Other .NET applications still capture exceptions manually with CaptureException.

CaptureExceptions was introduced in posthog-dotnet PR #198. Release availability was verified against tag PostHog.AspNetCore-v2.7.0, its shipped public API baseline, the current posthog-dotnet main branch, and the signed NuGet 2.7.0 package.

Changes

• Replace the handwritten ASP.NET Core exception middleware with the released PostHog middleware configuration.
• State the minimum supported package version.
• Clarify middleware ordering and preserve the generic .NET manual-capture guidance.

Validation

• pnpm format:docs
• pnpm exec markdownlint-cli2 contents/docs/error-tracking/installation/dotnet.mdx – 0 errors
• vale contents/docs/error-tracking/installation/dotnet.mdx – 0 errors; 2 unchanged dictionary warnings for dotnet and Blazor
• Published NuGet 2.7.0 package metadata and DLL API inspection
• Autoreview against origin/master – clean, no accepted/actionable findings
• Full Gatsby build, bundle checks, and Cloudflare Pages deploy – passed in the remote preview workflow
• All 19 PR checks – passed

Screenshot proof

The updated automatic-capture section in the rendered preview:

Residual risks

• The released NuGet DLL and metadata were inspected directly, but a separate local compile smoke test could not run because the .NET SDK was unavailable and the machine lacked space to install it.

Checklist

• I've read the docs and content style guides.
• Words are spelled using American English.
• Internal links remain relative.
• I've checked the changed page in the Cloudflare Pages preview build.
• No page was moved, so no redirect is required.

[github-actions]

Deploy preview

Status	Details	Updated (UTC)
🟢 Ready	View preview	Jul 22, 2026 06:40PM

[github-actions]

Vale prose linter → found 0 errors, 2 warnings, 0 suggestions in your markdown

Full report → Copy the linter results into an LLM to batch-fix issues.

Linter being weird? Update the rules!

contents/docs/error-tracking/installation/dotnet.mdx — 0 errors, 2 warnings, 0 suggestions

Line	Severity	Message	Rule
3:15	warning	'dotnet' is a possible misspelling.	PostHogBase.Spelling
20:65	warning	'Blazor' is a possible misspelling.	PostHogBase.Spelling

[github-actions]

Bundle report

Total JS (gzip)

6.75 MiB

No master baseline yet — deltas appear once the baseline workflow has run on master.

Eager graph (modules shipped in each entrypoint's initial chunks)

Entrypoint	Eager size	Budget	Modules
✅ app	16.23 MiB	report-only	1982

Largest modules in the app closure

Module	Size
./src/data/mcp-tools.json	895.2 KiB
css ./node_modules/.pnpm/css-loader@5.2.7_webpack@5.101.3/node_modules/css-loader/dist/cjs.js??ruleSet[1].rules[8].oneOf[1].use[1]!./node_modules/.pnpm/postcss-loader@4.3.0_postcss@8.5.6_webpack@5.101.3/node_modules/postcss-loader/dist/cjs.js??ruleSet[1].rules[8].oneOf[1].use[2]!./src/styles/global.css	747.2 KiB
./src/components/Stickers/Stickers.tsx	696.4 KiB
./node_modules/.pnpm/@radix-ui+react-icons@1.3.2_react@18.3.1/node_modules/@radix-ui/react-icons/dist/react-icons.esm.js	481.4 KiB
./node_modules/.pnpm/rehype-raw@7.0.0/node_modules/rehype-raw/lib/index.js + 29 modules	395.1 KiB
./node_modules/.pnpm/@posthog+icons@0.36.6_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/@posthog/icons/dist/posthog-icons.cjs.js	364.8 KiB
./src/hooks/useCustomers.tsx + 54 modules	355.1 KiB
./node_modules/.pnpm/@posthog+icons@0.36.6_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/@posthog/icons/dist/posthog-icons.es.js	354.8 KiB
./node_modules/.pnpm/react-markdown@8.0.7_@types+react@16.14.66_react@18.3.1/node_modules/react-markdown/lib/react-markdown.js + 88 modules	351.4 KiB
./node_modules/.pnpm/cloudinary-core@2.14.0_lodash@4.17.21/node_modules/cloudinary-core/cloudinary-core.js	281.9 KiB
./src/components/ProductComparisonTable/index.tsx + 120 modules	278.6 KiB
./src/components/SearchUI/index.tsx + 87 modules	272.1 KiB
./node_modules/.pnpm/framer-motion@10.18.0_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/framer-motion/dist/es/render/dom/motion.mjs + 109 modules	253.9 KiB
./node_modules/.pnpm/d3@7.9.0/node_modules/d3/src/index.js + 208 modules	247.4 KiB
./src/components/Pricing/PricingSlider/Slider.tsx + 87 modules	239.9 KiB

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Eager-graph budgets are report-only until a baseline is established. Sizes are gzip of public/**/*.js; eager size is webpack module source bytes for the modules actually shipped in the entrypoint's initial chunks (post-tree-shake).