Harnesses.
A harness is the runtime that executes an agent project: Claude Code, OpenCode, DeepAgents, Goose, Codex CLI, and other supported runtimes. Karta runs the project in its native harness format and freezes the resolved runtime on each release.
Each harness has its own project format. Karta does not translate your
agent into a proprietary workflow graph; it detects the harness, packages
the project, and deploys dedicated specialists from the same source folder
you develop locally. Add an optional [harness]
block only when you want to pin the runtime type or version explicitly.
# Create a new native agent project from the CLI.
karta create support-bot --harness claude-code
karta create research-bot --harness deepagents
karta create ops-goose --harness goose
karta create reviewer-codex --harness codex-cli
# Optional: pin the harness when folder layout is not enough.
[harness]
type = "deepagents" # supported harness id
version = "1" # optional constraint or exact pin; omit for curated defaultClaude Code claude-code
default version 2.1.152 - the version an omitted constraint resolves to
| Version | Status | Capabilities | Auth |
|---|---|---|---|
| 2.1.181 | supported | resume, approvals, file_upload, thinking | api_key, oauth_subscription |
| 2.1.152 | supported | resume, approvals, file_upload, thinking | api_key, oauth_subscription |
Codex CLI codex-cli
default version 0.133.0 - the version an omitted constraint resolves to
| Version | Status | Capabilities | Auth |
|---|---|---|---|
| 0.133.0 | supported | resume | api_key |
Deep Agents Code deepagents
default version 0.1.28 - the version an omitted constraint resolves to
| Version | Status | Capabilities | Auth |
|---|---|---|---|
| 0.1.28 | supported | - | api_key |
Goose goose
default version 1.39.0 - the version an omitted constraint resolves to
| Version | Status | Capabilities | Auth |
|---|---|---|---|
| 1.39.0 | supported | resume, thinking | api_key |
OpenCode opencode
default version 1.17.9 - the version an omitted constraint resolves to
| Version | Status | Capabilities | Auth |
|---|---|---|---|
| 1.17.9 | supported | resume | api_key |
Machine-readable: /harnesses.json. The CLI uses it for fast pre-flight feedback; release acceptance freezes the authoritative runtime for the release.