Declarative software

Set up Telos with your agent.

  • Install it with curl -fsSL https://usetelos.ai/install.sh | sh.
  • Run telos login to sign in to Telos Cloud.
  • Read the installed telos-cli skill to get started.

Goal-oriented software engineering

Telos is a platform to turn declarative goals into running software.

A goal is an executable contract (SPEC.md) paired with skills and rubrics that serves as your living source of truth. Telos continuously iterates towards the goal.

The current version of the Goal.Ready after all required checks pass.The model used by the system.The agent wakes up every 6h to check this deployment against its spec.Every Goal revision and what changed.Treat this as a required rubric, independently evaluated.The outcome you want.A live record of system work.
Telos
acme-labshalcyon
v1.2.0Ready
Deployed
Deployed 3w ago
Agent wake interval
6h
Model
Default
Spend
$24.68
Skills
service-checksv1.2.0
SKILL.md
checks.py
oncall-notifyv0.4.2
SKILL.md
routes.yaml

Goal

A public status page for Halcyon’s services.

  • Incidents post within a minute and persist.
  • GET /api/status returns every service with its current state.
  • History survives restarts and redeploys.

Acceptance

  • A new incident shows on the page within 60s.
  • 30 days of uptime history render for each service.
  • On-call is paged within 2 minutes of an incident opening.

Constraints

  • Page responds in under 200ms at the edge, uncached.
  • Incident history retained for a rolling 90 days.

Optimized for the agent experience

Telos works best when you collaborate with an interactive agent to iterate on your goals.

Read the docs

A persistent sandbox for every goal

Purpose-built for long-running agents

Persistent VM sandboxing built for long-running, stateful workloads (checkpoint/restore, default-deny egress, stable hostnames).

Complete developer toolchain

Over 40 common developer tools baked into the environment, for your most complex and diverse goals.

Build

Python, Node.js, Clang, Bazel, Git

Test

pytest, Playwright, Chromium

Operate

Kubernetes, Helm, OpenTofu

Inspect

Database, network, and observability tools

Flexible inference

Use Telos-managed models, a connected subscription, or your own API key.

telos/default
Balanced intelligence, cost, and latency.
telos/max
Frontier intelligence and multimodal work, at a higher cost.
ChatGPT and xAI
Uses your connected subscription allowances.
Your API keys (BYOK)
Use OpenAI, Anthropic, OpenRouter, or xAI with your own API key.
Hosted registry

Telos stores and hosts spec and skill packages: immutable, versioned artifacts resolved by exact digest.

How packages and skills work

Frequently Asked Questions

Does Telos work with Claude Code, Codex, and other coding agents?

Yes! Telos is designed to be driven by your coding agents. We expect you to write specs interactively with your coding agent and use Telos to delegate execution to the background.

What is the difference between Spec-Driven Development (SDD) and Telos?

Spec-driven development is a workflow that uses specs to steer creation of code. The code is still the artifact you maintain afterward and the final source of truth. In Telos the spec is the durable contract, the code is abstracted away, and Telos keeps them both reconciled.

How is Telos different from vibe coding platforms?

Telos is not an AI IDE or chatbot app builder, where imperative prompts guide AI agents and are disposed of after. Instead, specs are the declarative source of truth for the software — living, versioned artifacts.

How can Telos be confident about correctness given that AI is non-deterministic?

Telos uses a pair of adversarial coding agents that iterate until the spec has been satisfied. This serves as a forcing function for spec correctness against the desired contract. Read more on our work here.

Is Telos open source?

The Telos CLI (harness and framework) is source-available here. Telos Cloud provides managed agent execution and cloud hosting.

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