refactor(demo): use stock Spring Boot OTLP, drop JamJet @Configuration workaround

[sunilp]

Summary

Replaces the 73-LOC JamjetCloudConfiguration workaround with stock Spring Boot OTLP tracing. Now that jamjet-cloud PR #16 ships OTLP/protobuf intake to api.jamjet.dev, the demo can use the standard Spring Boot tracing autoconfig — no JamJet SDK on the classpath, no @Configuration, no observation handler.

Why the workaround existed

jamjet-cloud-spring-boot-starter:0.2.0 had two problems that made it unsuitable for a Spring-AI-only demo:

1. Its autoconfig hard-references LangChain4j classes, which would force langchain4j-core onto the classpath of every Spring AI app.
2. JamjetObservationHandler.supportsContext was called by Micrometer with the context name still null, so the handler never selected itself for Spring AI observations.

The workaround sidestepped both by skipping the starter, configuring JamjetCloud directly, and registering a context-class-filtered observation handler manually. That's now ~all unnecessary.

What changed

File	Change
pom.xml	Remove dev.jamjet:jamjet-cloud-sdk + io.micrometer:micrometer-observation; add io.micrometer:micrometer-tracing-bridge-otel + io.opentelemetry:opentelemetry-exporter-otlp
src/main/resources/application.yml	Drop jamjet.cloud.* block, add management.otlp.tracing.* block pointing at ${JAMJET_API_URL}/v1/otlp/v1/traces with Authorization: Bearer ${JAMJET_API_KEY}
src/main/java/.../cloud/JamjetCloudConfiguration.java	Deleted (-73 LOC)
src/test/java/.../DemoIntegrationTest.java	Override OTLP endpoint to localhost:1 + supply placeholder bearer in tests so Spring property resolver doesn't trip on unresolved ${JAMJET_API_KEY}
README.md + .env.example	Reflect the OTLP-based wiring

Net diff: +42, −99.

How observability flows now

Spring AI 1.0 chat call
  → emits Micrometer Observation (gen_ai.client.operation, gen_ai.tool, …)
    → micrometer-tracing-bridge-otel converts to OTel span
      → opentelemetry-exporter-otlp ships OTLP/HTTP-protobuf
        → POST https://api.jamjet.dev/v1/otlp/v1/traces
          → JamJet maps gen_ai.* attrs to typed fields, server-side cost fallback

No JamJet-specific code in the demo — observability is pure application.yml.

Test plan

• mvnw clean compile — clean build (release 21)
• mvnw test -Dtest=PreflightCheckTest — 5/5 pass
• mvnw spring-boot:run — app starts on :8080 in 1.3s, all autoconfig wires up cleanly (Tomcat, Engram, Spring AI, OTLP), PreflightCheck fails on Engram health check as expected without docker
• CI: full DemoIntegrationTest runs in Docker-enabled runner
• Post-merge: run the demo end-to-end with real OPENAI_API_KEY + JAMJET_API_KEY + Engram via docker, confirm trace appears at cloud.jamjet.dev/dashboard/graph tagged service.name=spring-ai-engram-cloud-demo

Followups

• Once jamjet-cloud-spring-boot-starter ships a Spring-AI-friendly variant (no LangChain4j hard ref + fixed observation handler), this demo can swap back to the starter for an even shorter pom — though "stock OTLP" is genuinely simpler and has no JamJet-specific class on the classpath, so we may stay on this approach
• The Kotlin Koog demo (examples/kotlin-koog-engram-cloud-demo) still uses a custom JamjetOtlpJsonSpanExporter (~100 LOC). With protobuf intake live, it can drop the custom marshaler in favor of the stock OTel exporter — separate PR

Summary by CodeRabbit

• Chores

  • Simplified the demo setup by transitioning from a custom SDK to standard OpenTelemetry/OTLP integration.
  • Updated example configuration files and dependencies to reflect the new observability approach.

• Documentation

  • Updated demo documentation to clarify the streamlined tracing flow using Spring Boot's built-in OTLP support without custom configuration.

[coderabbitai]

📝 Walkthrough

Walkthrough

The demo application is refactored to use Spring Boot's standard OTLP tracing infrastructure instead of the JamJet Cloud SDK. Dependencies shift to Micrometer's OTel bridge and OTLP exporter, configuration moves from custom jamjet.cloud properties to management.otlp.tracing, the custom JamjetCloudConfiguration class is removed, and all documentation and tests are updated accordingly.

Changes

Observability Architecture Refactor

Layer / File(s)	Summary
Dependencies & Build Configuration pom.xml	Maven dependencies replace jamjet-cloud-sdk and micrometer-observation with micrometer-tracing-bridge-otel and opentelemetry-exporter-otlp. The jamjet-cloud.version property is removed and comments updated to describe the Micrometer → OTel → OTLP/HTTP path.
OTLP Configuration & Environment .env.example, application.yml	Configuration switches from custom jamjet.cloud section to Spring Boot's management.otlp.tracing with endpoint at ${JAMJET_API_URL}/v1/otlp/v1/traces, Authorization bearer header from ${JAMJET_API_KEY}, and full sampling probability. Environment variable documentation clarifies OTLP trace export usage.
Custom Configuration Class Removal src/main/java/dev/jamjet/demo/springaiengram/cloud/JamjetCloudConfiguration.java	The entire JamjetCloudConfiguration class (73 lines) is deleted. Custom observation handler registration and JamJet Cloud initialization logic are no longer needed; Spring Boot's OTLP autoconfiguration handles all setup.
Documentation & Architecture Narrative README.md	README reframes observability as coming from Spring Boot configuration only: Micrometer Observations flow through OTel bridge, OTLP exporter, and to JamJet's hosted intake. Removes references to JamjetCloudConfiguration and custom handlers; updates configuration table to show OTLP tracing properties.
Test Configuration Updates src/test/java/dev/jamjet/demo/springaiengram/DemoIntegrationTest.java	Integration test now overrides management.otlp.tracing properties to prevent external trace export: redirects endpoint to non-routable address, disables sampling, and supplies placeholder Authorization header. Removes old jamjet.cloud.api-key and jamjet.cloud.api-url property overrides.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• jamjet-labs/jamjet-runtime-java#3: Refactors the same spring-ai-engram-cloud-demo example to migrate from JamJet SDK-based instrumentation to standard Spring Boot OTLP tracing with Micrometer bridge, updating dependencies, configuration, and documentation across the same files.

Poem

🐰 From SDK chains to OTLP streams so bright,
We hop through Micrometer's bridge day and night,
No custom class wrangling, just config so clean,
Spring Boot's wisdom flows through every scene!
The traces now journey through standards so true,
A simpler path forward for all to pursue. ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately captures the main refactoring: replacing a custom JamJet configuration workaround with standard Spring Boot OTLP tracing, which is reflected in the removal of JamjetCloudConfiguration and addition of OTLP dependencies.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/spring-ai-stock-otlp

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@examples/spring-ai-engram-cloud-demo/README.md`:
- Line 104: Update the README table entry for management.otlp.tracing.endpoint
to match the application.yml default by including the fallback value; change the
displayed expression to include the fallback :https://api.jamjet.dev so it
mirrors the config's JAMJET_API_URL fallback used in application.yml and avoids
implying JAMJET_API_URL is mandatory.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 721a08a1-853f-4415-a7b0-95079d70e9a8

📥 Commits

Reviewing files that changed from the base of the PR and between b4a33f8 and 4d3561c.

📒 Files selected for processing (6)

• examples/spring-ai-engram-cloud-demo/.env.example
• examples/spring-ai-engram-cloud-demo/README.md
• examples/spring-ai-engram-cloud-demo/pom.xml
• examples/spring-ai-engram-cloud-demo/src/main/java/dev/jamjet/demo/springaiengram/cloud/JamjetCloudConfiguration.java
• examples/spring-ai-engram-cloud-demo/src/main/resources/application.yml
• examples/spring-ai-engram-cloud-demo/src/test/java/dev/jamjet/demo/springaiengram/DemoIntegrationTest.java

💤 Files with no reviewable changes (1)

• examples/spring-ai-engram-cloud-demo/src/main/java/dev/jamjet/demo/springaiengram/cloud/JamjetCloudConfiguration.java

[coderabbitai]

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Align README default endpoint expression with actual config default.

Line 104 omits the fallback (:https://api.jamjet.dev) that exists in application.yml, so readers may assume JAMJET_API_URL is mandatory.

Suggested doc fix

-| `management.otlp.tracing.endpoint` | `${JAMJET_API_URL}/v1/otlp/v1/traces` | OTLP intake URL — defaults to JamJet's hosted intake |
+| `management.otlp.tracing.endpoint` | `${JAMJET_API_URL:https://api.jamjet.dev}/v1/otlp/v1/traces` | OTLP intake URL — defaults to JamJet's hosted intake |

📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change

	| `management.otlp.tracing.endpoint` | `${JAMJET_API_URL}/v1/otlp/v1/traces` | OTLP intake URL — defaults to JamJet's hosted intake |
	| `management.otlp.tracing.endpoint` | `${JAMJET_API_URL:https://api.jamjet.dev}/v1/otlp/v1/traces` | OTLP intake URL — defaults to JamJet's hosted intake |

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@examples/spring-ai-engram-cloud-demo/README.md` at line 104, Update the
README table entry for management.otlp.tracing.endpoint to match the
application.yml default by including the fallback value; change the displayed
expression to include the fallback :https://api.jamjet.dev so it mirrors the
config's JAMJET_API_URL fallback used in application.yml and avoids implying
JAMJET_API_URL is mandatory.