docs: add Java error tracking installation and library docs

[cat-ph]

Warning

DO NOT MERGE until the corresponding posthog-server release ships.

Most of this page documents API surface that is not released yet. Merging early would publish docs for methods users cannot call.

Gating features and the PRs that ship them:

Feature documented here	Gating PR
In-app frame config (inAppIncludes / inAppExcludes)	PostHog/posthog-android#670
releaseIdentifier (map_id for ProGuard symbolication)	PostHog/posthog-android#668 (merged, awaiting release)
Uncaught-exception opt-in (captureUncaughtExceptions)	PostHog/posthog-android#671
Logback module (posthog-server-logback, PostHogAppender)	PostHog/posthog-android#672
Exception coercion / frame plumbing the above build on	PostHog/posthog-android#669
Backend: Java pass-through in cymbal	PostHog/posthog#76829
Backend: Java source context fields	PostHog/posthog#76832

Both stacks are stacked drafts. Before merging: confirm the posthog-server and posthog-server-logback releases are out, then replace the two <!-- TODO: set minimum version on release --> placeholders with the real minimum versions.

Problem

There were no error tracking docs for the server-side Java SDK (posthog-server). The error tracking installation section covered other platforms but had no Java page, so JVM server users had no documented path to capturing exceptions, configuring in-app frames, or deobfuscating ProGuard/R8 builds.

Changes

• New page contents/docs/error-tracking/installation/java.mdx — full installation guide, structured as steps:
  • Install (Gradle + Maven), with an up-front note that source context is not supported yet
  • Initialize the client
  • Capture exceptions: personless by default, associating a person, extra properties, and PostHogCaptureOptions for groups / flags / timestamp
  • Associating exceptions with users via request context
  • Configuring in-app frames, including the SDK's default inAppExcludes list
  • Opting in to uncaught-exception capture
  • Capturing logged errors with the Logback appender
  • Deobfuscating stack traces with releaseIdentifier plus a PostHog CLI ProGuard upload
  • Verification snippet
  • A closing section on what is not supported yet (source context, framework middleware)
• Error tracking section added to contents/docs/libraries/java/index.mdx, plus errorTracking: true in the page's features frontmatter so the library page advertises the capability. Links out to the full guide.
• Nav entry for Java under error tracking installation in src/navs/index.js.

Verification

• API names checked against the current SDK implementation rather than from memory: config builder methods (inAppIncludes, inAppExcludes, releaseIdentifier, captureUncaughtExceptions), the documented captureException overloads, PostHogCaptureOptions builder methods, and PostHogAppender (setPostHog, minimumCaptureLevel defaulting to ERROR, apiKey / host self-config) all match.
• The documented default inAppExcludes list matches DEFAULT_IN_APP_EXCLUDES entry for entry.
• Buffer defaults refreshed to the current released values: the uncaught-exception caveat now cites flushAt default 100 and a 5 second flush interval, and explains that the real risk on the crash path is the asynchronous enqueue racing the synchronous flush(), with flushAt(1) as the mitigation.
• posthog-cli proguard upload confirmed as a top-level CLI command against contents/docs/cli.mdx.
• Every internal /docs/... link target resolves to an existing file on current master, and the #request-context anchor exists in the Java library page.
• node --check src/navs/index.js passes; exactly one Java error tracking nav entry.
• Not yet checked in a Vercel preview build — worth a look at the rendered steps and the callouts before merge.

Checklist

• I've read the docs and/or content style guides.
• Words are spelled using American English
• Use relative URLs for internal links
• I've checked the pages added or changed in the Vercel preview build
• If I moved a page, I added a redirect in vercel.json — n/a, no pages moved

[github-actions]

Deploy preview

Status	Details	Updated (UTC)
🟢 Ready	View preview	Aug 25, 2026 01:34PM

[github-actions]

Vale prose linter → found 6 errors, 44 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/java.mdx — 4 errors, 23 warnings, 0 suggestions

Line	Severity	Message	Rule
2:13	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
10:130	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
40:176	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
40:196	warning	'Symbolication' is a possible misspelling.	PostHogBase.Spelling
40:273	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
40:280	warning	'Deobfuscate' is a possible misspelling.	PostHogBase.Spelling
80:37	warning	'personlessly' is a possible misspelling.	PostHogBase.Spelling
113:32	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
133:252	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
133:331	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
189:145	warning	'enqueued' is a possible misspelling.	PostHogBase.Spelling
189:578	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
197:27	warning	'Logback' is a possible misspelling.	PostHogBase.Spelling
197:137	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
199:9	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
217:14	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
231:44	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
238:24	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
247:37	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
249:123	warning	Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept.	PostHogBase.ProductNames
252:87	warning	Use 'ID' instead of 'id'.	Vale.Terms
259:110	warning	'deobfuscated' is a possible misspelling.	PostHogBase.Spelling
259:130	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
277:130	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
283:104	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
303:124	warning	'Logback' is a possible misspelling.	PostHogBase.Spelling
303:132	warning	'appender' is a possible misspelling.	PostHogBase.Spelling

contents/docs/libraries/java/index.mdx — 2 errors, 21 warnings, 0 suggestions

Line	Severity	Message	Rule
6:18	warning	Use 'GitHub' instead of 'github'.	Vale.Terms
6:37	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
6:45	warning	Use 'Android' instead of 'android'.	Vale.Terms
123:192	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
123:208	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
164:219	warning	'personless' is a possible misspelling.	PostHogBase.Spelling
180:4	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'Feature flags' for the general industry concept.	PostHogBase.ProductNames
180:4	warning	'Feature flags' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
328:8	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
328:55	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
328:128	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
340:28	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
340:54	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
342:4	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'Error tracking' for the general industry concept.	PostHogBase.ProductNames
342:4	warning	'Error tracking' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
358:213	warning	'Logback' is a possible misspelling.	PostHogBase.Spelling
358:221	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
360:26	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
360:87	warning	'Logback' is a possible misspelling.	PostHogBase.Spelling
360:95	warning	'appender' is a possible misspelling.	PostHogBase.Spelling
360:137	warning	'deobfuscating' is a possible misspelling.	PostHogBase.Spelling
360:170	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
360:186	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames

[github-actions]

Bundle report

Total JS (gzip)

8.09 MiB (-0.2 KiB / -0.0%)

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

Entrypoint	Eager size	Budget	Modules
✅ app	16.88 MiB (-8.3 KiB / -0.0%)	report-only	2035

Largest modules in the app closure

Module	Size
./src/data/mcp-tools.json	1038.8 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	757.5 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
./src/hooks/useCustomers.tsx + 55 modules	369.8 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
./src/components/ProductComparisonTable/index.tsx + 126 modules	301.5 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/SearchUI/index.tsx + 87 modules	273.0 KiB
./node_modules/.pnpm/@posthog+brand@0.8.0_react@18.3.1/node_modules/@posthog/brand/dist/generated/hoggies/svg/magnifying-glass.mjs	254.7 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	240.1 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).