Spring Boot REST API (Java)

A Java JSON API on Spring Boot with Spring MVC and Actuator, built with Maven and make. One error envelope for every failure, validated settings, request ids and structured JSON logs, Error Prone and NullAway at compile time, and tests through Spring's MockMvc and a real server.

What done means

Your agent follows the brief, then runs stacks verify without weakening or skipping checks. What happens next

Declared steps: install, fmt-check, lint, compile, test, test-integration, build, api, readme-filled. View commands

Use this stack

Paste the prompt into the coding agent working on your project.

Full projectQuick local experiment

Uses the stack’s default fragments. Review the brief with your agent.Uses stated defaults and omits deploy, release, and app fragments unless explicitly requested.

View prompt

Use the spring-boot-api stack for this project. 1. Run npx @steamfield/stacks show spring-boot-api --json and check that it fits the project. If it does not, explain why before changing files. 2. Run npx @steamfield/stacks new spring-boot-api and follow the brief it prints. 3. From the generated project directory, run npx @steamfield/stacks verify. Fix failures without weakening or skipping verification steps. 4. Summarize what changed and the verification result. Quote published stats only when they are available, including their interval and sample size. The stacks docs, written for agents, are at https://stacks.steamfield.io/llms.txt.

Use the spring-boot-api stack for a quick local experiment. 1. Run npx @steamfield/stacks show spring-boot-api --json and check that it fits the project. If it does not, explain why before changing files. 2. Run npx @steamfield/stacks new spring-boot-api --sandbox and follow the brief it prints. 3. From the generated project directory, run npx @steamfield/stacks verify. Fix failures without weakening or skipping verification steps. 4. Summarize what changed and the verification result. Quote published stats only when they are available, including their interval and sample size. The stacks docs, written for agents, are at https://stacks.steamfield.io/llms.txt.

Or use the terminal

npx @steamfield/stacks new spring-boot-api

npx @steamfield/stacks new spring-boot-api --sandbox

Verify steps
Step	Phase	Layer	Command
install	setup	install	`make install`
fmt-check	check	lint	`make fmt-check`
lint	check	lint	`make lint`
compile	check	typecheck	`make compile`
test	check	test	`make coverage`
test-integration	check	test	`make test-integration`
build	check	build	`make build`
api	serve	serve	`make serve`
readme-filled	check	check	`test -s README.md && ! grep -n 'stacks:fill' README.md`

Usage and outcomes

Usage over time

Showing 180 days of history.

History

The 28-day green rate at each weekly observation. Gaps mean the sample was too small to publish.

Shaded band: 95% Wilson interval. Dashed rules: content changes. Missing observations remain gaps.

Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.

Data table

Through	Green rate	Projects	Content change
5 Jul 2026	hidden: too few projects	–	–
12 Jul 2026	hidden: too few projects	–	–
19 Jul 2026	hidden: too few projects	5	–
26 Jul 2026	hidden: too few projects	10	–
2 Aug 2026	hidden: too few projects	20	–
9 Aug 2026	hidden: too few projects	25	–
16 Aug 2026	hidden: too few projects	30	–
23 Aug 2026	hidden: too few projects	35	–
30 Aug 2026	77% (57–90%, n=20)	40	–
6 Sept 2026	78% (59–89%, n=25)	40	–
13 Sept 2026	79% (60–91%, n=25)	40	–
20 Sept 2026	83% (65–92%, n=30)	40	–
27 Sept 2026	76% (57–89%, n=25)	40	–
4 Oct 2026	hidden: too few projects	40	–
11 Oct 2026	77% (59–88%, n=30)	45	–
18 Oct 2026	71% (55–84%, n=35)	50	–
25 Oct 2026	76% (61–86%, n=40)	60	–
1 Nov 2026	73% (57–85%, n=35)	60	–

Weekly projects by preset

Non-overlapping seven-day project counts, grouped by the preset used to start the project.

default
sandbox

Stacks projects per UTC week through 4 Nov 2026. Published preset counts only; hidden cells are not zero.

Data table

Week ending	Preset	Projects
5 Jul 2026	default	–
12 Jul 2026	default	–
19 Jul 2026	default	–
26 Jul 2026	default	5
2 Aug 2026	default	5
9 Aug 2026	default	5
16 Aug 2026	default	5
23 Aug 2026	default	10
30 Aug 2026	default	10
6 Sept 2026	default	5
13 Sept 2026	default	5
20 Sept 2026	default	10
27 Sept 2026	default	10
4 Oct 2026	default	5
11 Oct 2026	default	10
18 Oct 2026	default	10
25 Oct 2026	default	10
1 Nov 2026	default	10
5 Jul 2026	sandbox	–
12 Jul 2026	sandbox	–
19 Jul 2026	sandbox	–
26 Jul 2026	sandbox	–
2 Aug 2026	sandbox	–
9 Aug 2026	sandbox	–
16 Aug 2026	sandbox	–
23 Aug 2026	sandbox	–
30 Aug 2026	sandbox	5
6 Sept 2026	sandbox	–
13 Sept 2026	sandbox	–
20 Sept 2026	sandbox	–
27 Sept 2026	sandbox	–
4 Oct 2026	sandbox	–
11 Oct 2026	sandbox	–
18 Oct 2026	sandbox	10
25 Oct 2026	sandbox	5
1 Nov 2026	sandbox	5

By preset

Green verify outcomes by the preset chosen at scaffold time.

default

73%52–87%, n=20

sandboxhidden: too few projects

Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.

Data table

Name	Green rate	Projects
default	73% (52–87%, n=20)	40
sandbox	hidden: too few projects	20

By agent

Within this stack, listed alphabetically. These are project outcomes, not an agent ranking.

Not enough runs in this breakdown yet.

Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.

Time to green

Published time summaries on a shared minutes scale. First passing test is a median; 75% reached green by the 75th percentile.

Verify runs to green: 1

Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.

Data table

Measure	Time / runs
Median to green	25 minutes
75th percentile	31 minutes
First passing test	15 minutes
Verify runs to green	1

Where it breaks

A run can fail more than one step. Environment failures are shown separately.

test-integration28%

test23%

lint18%

build13%

install10%

fmt-check8%

api3%

Environment blocked0%

Share of failed runs before first green. Environment blocked describes the machine, not the stack.

Data table

Step	Share
lint	18%
test	23%
build	13%
install	10%
test-integration	28%
fmt-check	8%
api	3%
Environment blocked	0%

What people change

Defaults people keep, and optional fragments they choose to attach.

Default, kept rate

agent-ops92%

git-hooks92%

ci-githubhidden: too few projects

rest-apihidden: too few projects

Optional, attach rate

rr12%

ce-plugin12%

Share of the window's 60 projects. Kept rate is 1 minus the without rate.

Data table

Fragment	Measure	Share
agent-ops	Kept	92%
git-hooks	Kept	92%
ci-github	Kept	–
rest-api	Kept	–
rr	Attached	12%
ce-plugin	Attached	12%

By composition 12 fingerprints

Each row is a distinct fragment composition, with its own sample and content history.

Composition	Green rate	Seen	Change in life
defaults + rr − rest-api · 1720d86b	hidden: too few projects	11 Oct 2026 – 1 Nov 2026	None
defaults + ce-plugin · 27a0fe68	hidden: too few projects	12 Jul 2026 – 1 Nov 2026	None
defaults + rr − agent-ops · 2db321c6	hidden: too few projects	23 Aug 2026 – 1 Nov 2026	None
defaults − ci-github · 435520b5	hidden: too few projects	12 Jul 2026 – 1 Nov 2026	None
defaults + rr · 6698442a	hidden: too few projects	19 Jul 2026 – 1 Nov 2026	None
defaults − agent-ops − git-hooks · 79165d65	hidden: too few projects	23 Aug 2026 – 1 Nov 2026	None
defaults − rest-api · 8d29d388	hidden: too few projects	19 Jul 2026 – 1 Nov 2026	None
defaults − agent-ops · a2264423	hidden: too few projects	16 Aug 2026 – 1 Nov 2026	None
defaults + ce-plugin − rest-api · d6b53f62	hidden: too few projects	20 Sept 2026 – 1 Nov 2026	None
defaults − git-hooks · d8c87907	hidden: too few projects	26 Jul 2026 – 1 Nov 2026	None
defaults + ce-plugin + rr · ed66a6ea	hidden: too few projects	25 Oct 2026 – 1 Nov 2026	None
defaults · ffc1465c	71% (53–85%, n=30)	26 Jul 2026 – 1 Nov 2026	None

Computed 5 Nov 2026, through 4 Nov 2026. Numbers describe stacks projects, not the ecosystem.