GravityKit
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Comparison · Infra & APIs
Ably vs Clerk
A side-by-side editorial comparison of Ably and Clerk — release velocity, themes, recent moves, and the top alternatives to consider.
Ably vs Clerk: at a glance
| Feature | Ably | Clerk |
|---|---|---|
| Sector | Infra & APIs | Infra & APIs |
| Velocity score | 7.5 | 0.0 |
| Sparks · 30d | 2 | 0 |
| Top themes | ai transport, realtime messaging, agents, mau-billing | authentication, machine-auth, agent-tooling, scim |
| Last editorial update | 21h ago | 3mo ago |
| Website | — | Visit → |
What is Ably?
Ably's AI Transport hits 1.0 and plugs straight into Vercel's useChat with resumable streams.
Ably is repositioning its realtime pub/sub network as the transport layer for AI agent output. AI Transport JS 1.0 runs on ordinary Pub/Sub channels and ships adaptors for the Vercel AI SDK, OpenAI Responses API and AG-UI, plus a useChat transport that resumes a stream after a reload. It lands a week after the switch to monthly-active-user pricing and breaking SDK majors that split every client into device and server packages.
What is Clerk?
Clerk is building auth for machines: API keys, a CLI agents can drive, per-verification pricing.
Two threads dominate. The first is machine authentication: API keys reached general availability with usage-based billing at $0.001 per creation and $0.00001 per verification, and a new CLI is described as a tool for developers and their agents to manage auth and billing. The second is enterprise readiness — Directory Sync (SCIM) generally available with custom attribute mapping and IdP role assignment, plus an Application Logs event stream across auth, billing, and organizations. Dashboard polish and Expo theming fill in around them.
Ably vs Clerk: editorial side-by-side
Ably
7.5INFRA · APIS
Ably's AI Transport hits 1.0 and plugs straight into Vercel's useChat with resumable streams.
◆ Current state
Ably is repositioning its realtime pub/sub network as the transport layer for AI agent output. AI Transport JS 1.0 runs on ordinary Pub/Sub channels and ships adaptors for the Vercel AI SDK, OpenAI Responses API and AG-UI, plus a useChat transport that resumes a stream after a reload. It lands a week after the switch to monthly-active-user pricing and breaking SDK majors that split every client into device and server packages.
◆ Where it's heading
The November releases fit one plan: split clients so MAU billing can count end users, then make the AI layer a thin adaptor on top of the same channels used for chat, presence and LiveObjects. Server-side additions in Java and JS (HTTP LiveObjects, channel pools, a Temporal plugin) point at agent backends as the intended publisher.
◆ Prediction
Expect more agent framework adaptors and server SDKs reaching AI Transport parity, with Chat and LiveObjects examples built around agents joining human conversations.
Clerk
0.0INFRA · APIS
Clerk is building auth for machines: API keys, a CLI agents can drive, per-verification pricing.
◆ Current state
Two threads dominate. The first is machine authentication: API keys reached general availability with usage-based billing at $0.001 per creation and $0.00001 per verification, and a new CLI is described as a tool for developers and their agents to manage auth and billing. The second is enterprise readiness — Directory Sync (SCIM) generally available with custom attribute mapping and IdP role assignment, plus an Application Logs event stream across auth, billing, and organizations. Dashboard polish and Expo theming fill in around them.
◆ Where it's heading
Clerk is extending from human sign-in toward credentials for software acting on a user's behalf, and pricing that surface by the call rather than by the seat. The CLI framing makes the direction explicit: the control plane should be operable by an agent, not only by a person in a dashboard. Meanwhile SCIM, logs, and billing controls are the enterprise checklist that lets it sell upmarket while that bet plays out.
◆ Prediction
Expect the machine authentication suite to deepen around delegated and scoped access for agents — finer-grained key permissions or short-lived credentials — with usage-based pricing extended to whatever ships next.
Alternatives to Ably and Clerk
Other Infra & APIs products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Ably or Clerk.
Payload CMS
Payload's v4 beta.9 keeps every past image crop and raises the Node floor again.
Nautobot
Nautobot 3.3 alpha 2 adds test helpers and a cable location filter after 3.2.9's token-leak fix.
Clair
Clair 4.10 RC can read SBOMs to match Java vulnerabilities.
Shuffle
Shuffle tags builds almost daily, but the notes are empty.
KrakenD
KrakenD's community edition is shipping only dependency bumps.
Recent activity from Ably and Clerk
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoAblyAI Transport 1.0 makes Ably a resumable transport for AI chat ⚡
- 2d agoAblyJava SDK 2.1 reads and updates LiveObjects over HTTP
- 3d agoAblyJS SDK 3.1 adds channel pools and a Temporal plugin
- 4d agoAblyAbly Kafka Connector v4.2.1
- 8d agoAblyMonthly active user (MAU) pricing ⚡
- 8d agoAblyAbly Chat React UI Kit v0.4.0
- 6mo agoClerkImproved observability with Application Logs
- 6mo agoClerkClerk CLI ⚡
- 7mo agoClerkAPI keys reach GA with usage-based billing active
- 7mo agoClerkAPI Keys General Availability
- 7mo agoClerkTheme Expo native components from a JSON fileCategorySDKPublishedApr 16@clerk/expo now supports a JSON-based theme for native iOS and And…
- 7mo agoClerkDirectory Sync (SCIM) hits GA with custom attribute mapping
Frequently asked questions
What is the difference between Ably and Clerk?
They serve adjacent needs but don't currently overlap on shipped themes. Ably is currently shipping more aggressively (velocity 7.5 vs 0.0), with 2 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Ably better than Clerk?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Ably is currently shipping more aggressively (velocity 7.5 vs 0.0), with 2 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Infra & APIs products to evaluate alongside.
What are the best alternatives to Ably?
Top Ably alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "Ably alternatives" section above for the current picks, or visit /alternatives/ably for the full list with editorial commentary on each.
What are the best alternatives to Clerk?
Top Clerk alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "Clerk alternatives" section above for the current picks, or visit /alternatives/clerk for the full list with editorial commentary on each.