CrystalSpec vs AWS Kiro
The spec workspace vs the spec IDE.
Kiro made spec-driven development mainstream — and proved that developers want a human gate on AI output. CrystalSpec agrees, one layer up: a team workspace where the spec is typed, versioned, and queryable by any coding agent over MCP — not markdown living inside one developer's editor.
Free 14-day trial. No credit card. Cancel in two clicks.
- CrystalSpec's one flat plan — no tier puzzle
- $10/seat
- Kiro's credit tiers, as of mid-2026
- $20–$200/mo
- AI credits included per member, every month
- 5,000
- Cost of reviewing proposals — only generation spends credits
- $0
Kiro was right about specs. Now zoom out one layer.
Credit where it's due: Kiro is the most complete spec mode shipped in any IDE. AWS's agentic editor — a VS Code fork plus a CLI that keeps your settings and Open VSX plugins — went viral in preview in July 2025, hit general availability that November, and by mid-2026 had drawn 250,000+ developers. Its signature move turns a prompt into three gated artifacts per feature: requirements.md with EARS-notation acceptance criteria, design.md with architecture and diagrams, and tasks.md — each requiring your approval before the next phase. Then it executes those tasks in parallel waves and, since GA, checks the code against the spec with property-based testing. If you're searching for a Kiro alternative, start by understanding what Kiro genuinely got right.
What it got right is the philosophy CrystalSpec is built on too: AI drafts, humans approve. The divergence is where the spec lives and who it serves. Kiro's specs are per-feature markdown files in .kiro/specs/ — implementation plans that serve a build and then, as users report in community threads and issue trackers, drift from the code as iterations continue. Steering files carry the durable project knowledge, but the spec itself is scoped to a feature, bound to an IDE, and readable only by whoever has the repo open. The spec shouldn't live inside one developer's editor. Your PM can't open a pull request to question an acceptance criterion; your stakeholder can't review a design doc buried three directories deep in a repo they can't access.
CrystalSpec is what spec-driven development looks like as a team workspace instead of a developer tool. Specs are typed entities, not documents: flows with decision points rendered as live diagrams, data models with typed fields and references, roles, test cases, glossary terms — one cross-referenced vocabulary. Each AI edit shows up as a validated proposal; you accept or decline it row by row, and the decision is logged either way. Editing forks a draft revision; publishing stamps a new version, diffs it field by field, and pushes AI-decomposed atomic tasks to GitHub, Linear, or ClickUp. And because the spec is served over a hosted MCP server, a scoped GraphQL API, and HMAC-signed webhooks, any agent can query it — Claude Code, Claude Desktop, Cursor — while your developers keep the editor they already love. Kiro's spec workflow requires working in Kiro; CrystalSpec's requires nothing but a browser and whatever agent you run.
Then there's the bill. As of mid-2026, Kiro's pricing spans a free 50-credit tier, then $20, $40, $100, and $200 per month per developer, with $0.04-per-credit overage — and named frontier models cost roughly 1.3x versus the "Auto" router. Users report that long spec sessions burn credits fast; it's the most cited pain point behind "Kiro alternative" searches. CrystalSpec's posture is deliberately boring: one Team plan at $10 per seat per month, 5,000 AI credits per member refreshed monthly, shared one-time top-ups, and reviewing proposals never costs a credit. One price. No tier puzzle.
A workspace the whole team can stand in
Kiro optimizes the developer's inner loop. CrystalSpec optimizes the artifact everyone depends on.
Everyone authors, not just engineers
A web workspace with discussions, @mentions, server-side permissions, no-account share links, and PDF export — PMs and stakeholders included.
The spec outlives the feature
One living spec with published revisions as the source of truth — not per-feature markdown that users report drifting as code iterates.
Git-style revisions for decisions
Drafts locked to one active editor, field-level diffs, AI-drafted change summaries, and any version revertible with full lineage.
Any agent, not one IDE
A hosted MCP server for Claude Code, Claude Desktop, and Cursor, plus GraphQL and signed webhooks. Keep your editor and your agent.
Inconsistency analyzer
Run it across the whole project — or one flow, or a single step — and it flags what per-feature spec folders never see: contradictions between flows, coverage gaps, glossary terms nothing references. 'Fix all with AI' answers with proposals you still review.
Tracker handoff built in
Publishing decomposes changes into atomic tasks in GitHub, Linear, or ClickUp — re-running the push adds nothing twice, and every task keeps a link to its revision.
An honest read on the choice
Choose CrystalSpec if…
- Your spec has to serve PMs, designers, engineers, and stakeholders — not just whoever has the repo open.
- You want approval on every individual change, recorded forever — not only gates between phases.
- Your developers already have editors and coding agents they like; the spec should be served to all of them over MCP.
- You want publishing to push atomic, back-linked tasks to GitHub, Linear, or ClickUp automatically.
- You'd rather pay a flat $10/seat than manage credit tiers per developer.
Choose AWS Kiro if…
- You want spec-to-implementation in one tool: Kiro plans and writes the code, then checks it against the spec with property-based testing.
- You're a solo developer or a small eng-only team whose spec naturally lives beside the code in the repo.
- You're deep in AWS — IAM Identity Center, GovCloud — or eligible for its startup program (a year of free Pro+).
- You want EARS-notation acceptance criteria generated per feature, right inside your editor.
Spec workspace vs spec IDE, feature by feature
| Dimension | CrystalSpec | AWS Kiro |
|---|---|---|
| What it is | Web spec workspace for the whole team | Agentic IDE (VS Code fork) + CLI |
| Spec artifact | Yes: Typed flows, data models, roles, test cases, glossary | Partial: requirements.md / design.md / tasks.md per feature |
| Spec durability | Yes: Living spec; published revisions are the source of truth | Partial: Steering files durable; per-feature specs drift (user-reported) |
| Human approval of AI output | Yes: Every change a validated proposal; decisions recorded | Yes: Phase gates: requirements → design → tasks |
| Who can author | Yes: PMs, designers, engineers — web app with permissions | Partial: Developers inside the IDE |
| Code generation | No: Feeds your agents via MCP instead | Yes: Executes tasks in parallel waves |
| Agent compatibility | Yes: Hosted MCP + GraphQL + webhooks — any agent queries it | Partial: Its own agent; MCP client support |
| Versioning | Yes: Diffs down to the field, AI-written summaries, revert with lineage | Partial: Git commits on markdown |
| Consistency checking | Yes: Analyzer grades contradictions, gaps, dead terms | Partial: Property-based tests check code against spec |
| Tracker integration | Yes: Push to GitHub, Linear, ClickUp — re-run-safe, back-linked | No: Nothing native; generic MCP plumbing |
| Sharing with stakeholders | Yes: Read-only public links, AI Q&A, PDF export | No: Repo access required |
| Pricing | $10/seat/mo flat; 5,000 credits/member included | Free (50 cr), $20–$200/mo tiers + $0.04/credit overage |
Kiro details from kiro.dev docs and pricing as of mid-2026; spec-drift and credit-burn criticisms are community-reported, not vendor statements. CrystalSpec claims from crystalspec.com.
Kiro proved developers want a human gate on AI output. CrystalSpec moves that gate to where the whole team can stand behind it.
Kiro vs CrystalSpec, asked straight
Aren't CrystalSpec and Kiro doing the same thing?
They share a philosophy — spec first, human approval on AI output — but at different layers. Kiro is an agentic IDE that specs and then builds one feature at a time, inside the editor. CrystalSpec is the team's spec workspace above every IDE: typed flows, data models, roles, and test cases, versioned like code and queryable over MCP by whatever coding agent you already use.
Can I use CrystalSpec together with Kiro?
In principle, yes: Kiro supports MCP clients, and CrystalSpec ships a hosted MCP server — though CrystalSpec's verified client list is Claude Code, Claude Desktop, and Cursor; other MCP-compatible tools may work. The natural split is that the durable product spec lives in CrystalSpec while Kiro handles implementation inside the repo.
What happens to Kiro specs after the feature ships?
They stay as markdown in .kiro/specs/ — and the community's most common complaint is that these per-feature files drift from the code as iterations continue. CrystalSpec's published revisions, field-level diffs, and inconsistency analyzer exist precisely to keep one spec continuously true rather than a stack of implementation snapshots.
How do the prices compare?
As of mid-2026, Kiro runs $20 to $200 per month per developer across credit tiers, with $0.04-per-credit overage — and users report that long spec sessions consume credits quickly. CrystalSpec is a flat $10 per seat per month with 5,000 AI credits per member included and refreshed monthly, and reviewing AI proposals never costs credits — only generation does.
Where do PMs and designers work in each tool?
Kiro is a developer IDE; non-engineers don't live in a code editor. CrystalSpec is a web workspace where PMs, designers, and engineers author together: AI-assisted editing, discussions with @mentions, permissions enforced server-side, read-only share links that need no account, and a PDF export of the whole spec polished enough for a board meeting.
Does CrystalSpec write code like Kiro does?
No — deliberately. CrystalSpec produces a rigorous, versioned spec plus atomic tracker tasks pushed to GitHub, Linear, or ClickUp, and serves that spec to your coding agents over MCP and GraphQL. Your agents implement; the spec stays the contract. If you want planning and code generation in one tool, that's Kiro's territory.
Is Kiro's approval flow the same as CrystalSpec's?
Same instinct, different granularity. Kiro gates phase transitions: you approve requirements, then design, then tasks. CrystalSpec validates and gates every individual create, update, or delete as a proposal you approve or reject row by row — and each decision goes into the history, a rejected proposal staying there alongside the name of whoever turned it down.
The verdict
Pick Kiro when one developer should spec and build a feature in the same tool. Pick CrystalSpec when the spec is the team's contract — typed, versioned, human-approved, and queryable by every agent you run.
Free 14-day trial. No credit card. Cancel in two clicks.