Directory / Tessl
Tessl
Verified
Spec-first platform for building software with agents.
Tessl is a product around specification-driven development with coding agents: the spec is the durable artifact, the agent implements against it. It sits in intent (and a bit of execution) rather than as a generic IDE.
- Model independence
- Multi-model
- Deployment
- Cloud
- Open source
- No
- License
- Proprietary
- Pricing model
- Mixed
- Added / updated
- 19 Aug 2026 / 19 Aug 2026
Editorial take
Tessl is one of the few commercial bets that the spec, not the chat, is the factory object. That matches this site’s intent-layer guide. Young product. We have no production metrics. Read their docs, not a recap.
Strengths
- Spec as the interface to the agent.
- Closer to a factory inbox than an autocomplete plugin.
- Multi-model in current materials.
Limitations
- Closed, early, category still forming.
- Not a sandbox vendor.
- No independent case study in this directory yet.