Comparison

WireMock vs Gostly

WireMock is the JVM-anchored elder of HTTP mocking — 15 years of stub DSL maturity. Gostly is a newer, lighter take built around recorded traffic instead of authored stubs. Both are good products; they optimise for different teams.

WireMock OSS has been mocking HTTP since 2011 and has earned its mindshare honestly. The stub-matching DSL is one of the most expressive in the field, the JUnit story (@WireMockTest) is genuinely best-in-class for Java teams, and WireMock Cloud layers collaboration, OpenAPI bidirectional sync, and a chaos UI on top. If your service is a Spring Boot app and your developers already think in builders, WireMock is the conservative choice and the right one.

Gostly is built around a different starting assumption: most teams do not want to author stubs at all. They want the mock to come from the traffic their service is already serving. So Gostly ships as a single Rust binary you put in front of your upstream, runs in LEARN mode for an hour or so, then flips to MOCK mode and replays. AI fills any gap — but grounded by the recordings, not by a free-text prompt.

There is no JVM in the loop, the install is a curl, and the wire protocol is language-agnostic. The trade-off is real: WireMock's stub DSL is deeper, its matchers are sharper, and its plugin ecosystem is mature in ways Gostly is not yet.

Feature comparison

Feature	WireMock	Gostly
OSS core	Apache 2.0 (Java)	FSL (Rust)
Single binary, no JVM	No	Yes
Stub authoring DSL (programmatic)	deep, mature	basic; record-first
Records mocks from real upstream traffic	via proxy mode	default workflow
JUnit / pytest / Jest helpers	JUnit excellent	pytest + Jest planned
OpenAPI bidirectional sync	Cloud only	import shipping
gRPC	Cloud + OSS extension	roadmap
Chaos / fault injection	Cloud (% slider, status faults)	shipping (latency, status); stateful chaos roadmap
Self-hosted control plane	Runner hybrid	single binary or K8s
AI gap-fill grounded by your traffic	No	Yes
SAML / RBAC / audit log	Enterprise tier	roadmap (2026)

Roadmap items are explicitly labelled. Stateful chaos, SAML / RBAC, and gRPC are 2026 roadmap on Gostly's side, not shipping today.

Choose WireMock when

→Your services are JVM and you want @WireMockTest JUnit integration.
→You compose stubs programmatically and want a deep, expressive matcher DSL.
→Advanced request matching (regex, JSONPath, XPath, custom Java matchers) is part of your test design.
→You need gRPC today and the WireMock gRPC extension fits your toolchain.

Choose Gostly when

→Your services span Python, Node, Go, Ruby, Rust — anything that is not JVM-first.
→You would rather record an hour of real traffic than author a week of stubs.
→Operability matters: you want a single Rust binary, not a JVM to size and tune.
→You want AI gap-fill that mimics endpoint-specific patterns from your traffic, not LLM-prompted hallucinations.

Pricing, side by side

Tier	WireMock	Gostly
Free / OSS	WireMock OSS (Apache 2.0) · Cloud free 1k req/mo	OSS proxy (FSL) · unlimited services free
Pro / Solo	No single-seat tier; jumps to Team	$10 / mo single user
Team	$47 / mo Cloud Team (10k req / mo cap)	/ seat / mo
Self-host / Enterprise	Cloud Enterprise — custom; OSS self-host always free	$499 / mo Self-host · $25K+ Enterprise

WireMock Cloud Team's $47 is genuinely cheaper sticker-price than Gostly Team's $79 — and meters per request. Whether that is the right shape depends on traffic volume: at 10k requests / mo WireMock is the value choice, at 1M requests / mo (where most CI fleets land) the per- request meter compounds and Gostly's flat seat price wins. Self-host both are free for OSS; both ship a paid self-host tier for support and gated features.

Switch in 2 minutes

Point the Gostly CLI at your existing WireMock mappings/ directory or standalone zip. Each stub becomes a flat mock with the same method, URL, status, and body. Stateful scenarios and priority ordering are dropped (Gostly serves first-match in input order) and surfaced as warnings so you know what didn’t carry over.

$ gostly import --format wiremock \
    --service-id svc-stripe ./mappings.zip
✓ Imported 124 mocks from ./mappings.zip
  ! mapping mappings/checkout.json#0: priority=5 dropped — Gostly uses flat first-match ordering
  ! mapping mappings/checkout.json#0: scenario state ('Cart') dropped — stateful chaos is on the drift v2 roadmap

The importer accepts a single mappings JSON, a JSON array, the {mappings: [...]} envelope wiremock --record-mappings emits, or a zip with mappings/*.json + __files/ resolved automatically.

Try Gostly without the JVM

Single binary, language-agnostic, recording-first. Run it against your staging upstream for an hour and see whether it produces a mock you trust.

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