Top accelerator startups

Startups14,448Programs29

14,448 startups · 29 programs

OpenSpec

Active · Plan mode for complex features

WebsiteYC profile

Why it ranks

How the rank works
4signal of 100 · rising 4
  • went through YCProgram · this site+4

A sum of public facts, not a judgement and not investment advice.

Competitors

AIAcquiredContinueShared: coding agent, open, sourceYC S23San FranciscoStartup →AIJcodeShared: github star, coding agent, developerYC S26San FranciscoStartup →AIOpenCodeShared: coding agent, open, sourceYC W21TorontoStartup →AIScott AIShared: coding agent, planningYC F25New York CityStartup →AITraceRoot.AIShared: coding agent, ship, openYC S25San FranciscoStartup →
Companies closest to OpenSpec
Company
ContinueShared: coding agent, open, sourceYC S23AcquiredAI, Devtools
JcodeShared: github star, coding agent, developerYC S26ActiveAI, Devtools
OpenCodeShared: coding agent, open, sourceYC W21ActiveAI, Devtools
Scott AIShared: coding agent, planningYC F25ActiveAI, Devtools
TraceRoot.AIShared: coding agent, ship, openYC S25ActiveAI, Devtools

Adjacent

AIBrowser UseShared: github star, agent, openYC W25San FranciscoStartup →AISynthShared: coding agent, contextYC F24San FranciscoStartup →AIZep AIShared: github star, framework, contextYC W24San FranciscoStartup →AIFreebuffShared: coding agent, open, sourceYC F24San FranciscoStartup →AIRelaceShared: coding agentYC W23San FranciscoStartup →
Companies next to OpenSpec
Company
Browser UseShared: github star, agent, openYC W25ActiveAI, Devtools
SynthShared: coding agent, contextYC F24ActiveAI, Devtools
Zep AIShared: github star, framework, contextYC W24ActiveAI, Devtools
FreebuffShared: coding agent, open, sourceYC F24ActiveAI, Devtools
RelaceShared: coding agentYC W23ActiveAI, Devtools

Also from W26 in AI

All of W26
AI/dev/fast/dev/fast is the AI-native code forgeYC W26San FranciscoStartup →AI10x ScienceThe AI-native platform for next-generation protein characterization.YC W26San FranciscoStartup →AI21stUI building blocks for the agentic internetYC W26San FranciscoStartup →AIAemonThe Forward-Deployed AI Research EngineerYC W26San FranciscoStartup →AIAgentic FabriqThe control plane for AI agents.YC W26San FranciscoStartup →AIAlt-XBuilding the best venue for private markets exposure.YC W26Los AngelesStartup →
Company
/dev/fast/dev/fast is the AI-native code forgeteam of 4ActiveAI, Devtools
10x ScienceThe AI-native platform for next-generation protein characterization.team of 5hiringActiveAI
21stUI building blocks for the agentic internetteam of 3ActiveAI, Devtools
AemonThe Forward-Deployed AI Research Engineerteam of 3hiringActiveAI, Devtools
Agentic FabriqThe control plane for AI agents.team of 2ActiveAI
Alt-XBuilding the best venue for private markets exposure.team of 2ActiveAI, Data

Founders

  • Tabish BidiwaleFounder

About OpenSpec

OpenSpec is an open-source, spec-driven framework. We help developers plan complex features by creating lightweight spec documents that serve as durable context for their coding agents. With 20k+ GitHub stars, we’re one of the leading spec-driven frameworks, used by thousands of developers and teams to plan and ship with the coding agent of their choice. Our philosophy is simple: keep planning lightweight and iterative, and match how software actually gets built, messy, evolving, and real, without dragging teams into rigid, bureaucratic workflows.

YC batch
W26 · Winter 2026
Status, per YC
Active
Category
AI, Developer tools
Location
Sydney, NSW, Australia
Founded
2025
Checked
13h ago

OpenSpec in W26: 199 companies, 81% AI

OpenSpec: questions

Which YC batch was OpenSpec in?

OpenSpec was in Y Combinator's Winter 2026 batch (W26).

Is OpenSpec still active?

Y Combinator lists OpenSpec as active.

Who founded OpenSpec?

OpenSpec's founders, as listed on its YC page: Tabish Bidiwale (Founder).

Where is OpenSpec based?

OpenSpec lists Sydney, NSW, Australia as its location on YC's directory.