Harness vs Sculptor

Harness 85

Read as an MCP server and CLI. Eleven tools in source at v0.5.33, each with a typed JSON Schema input built by one helper, required fields marked, plus --json on every command. No OpenAPI, which a stdio server does not need (23). llms.txt and a Markdown-like agents page written for agents, per the 17 October check, not re-read on 4 November, since Autonomous's terms forbid access to its sites by automated means, including scripts or web crawlers, and its hosts are paused pending the founder (10). The tool descriptions and server instructions say when to call whoami first, to prefer a new project over an existing folder, to read before telling a harness more, and that turning a setting on is the person's yes to give (20). An enum on agent and on the setting name, minItems on wait names, minimum and maximum on timeout_seconds, a minimum on chars and limit. machine, folder, project and model are free strings (12). Worked examples, the exit code table and the Next: line per the 17 October reading of the agents page and llms.txt, with exit codes still in the source (13). Per-component semver tags, but the only CHANGELOG.md covers the provider protocol (0.3.0, 6 August 2026), and GitHub's release pages could not be read (7). 23 + 10 + 20 + 12 + 13 + 7 = 85.

Sculptor 45

Harness reading. A README, specs and agent docs in the repository; no API reference (45).

Harness 77

Eleven tools at v0.5.33 (seven on 17 October). Added since then are harness_search, harness_machines, harness_tell and harness_settings; harness_send and harness_tell are listed only inside a harness, so an agent outside one sees nine. Descriptions total about 4,000 characters. Judgement call. By the total, 11 tools fall in the 11 to 30 band (15), with 5 back for listing two tools only inside a harness (20). Counting only the nine an outside agent sees gives 25. We took the stricter reading, as the 17 October check counted the total (20). chars sizes a read (4,000 characters by default), limit sizes a search (10 by default), all widens the list, and any returns on the first finished harness. No pagination (14). Exit codes, refusals returned as answers rather than errors so a model does not retry them, and a timed-out wait reported as still working, in the source (19). readOnlyHint on whoami, list, search, machines, wait and read, destructiveHint false on start, tell and send, idempotentHint on close, and no hint on settings so an engine that asks before an unmarked tool asks the person (16). Two required fields on start, defaults of Claude Code and a 45-second wait. No SDK, but a CLI, an MCP server and a plugin with a skill (8). 20 + 14 + 19 + 16 + 8 = 77.

Sculptor 50

Harness reading. Workspaces as isolated copies, review and merge back, and built-in skills (50).

Harness 40

No payment protocol (0). Read with the self-hosted rule. The software is free and the optional hardware prices are public, per the 17 October check, not re-read on 4 November, since Autonomous's terms forbid access to its sites by automated means, including scripts or web crawlers, and its hosts are paused pending the founder (20). Free with no card (20). An agent cannot start harnesses until the person signs in with Google or Apple in a browser; the agent can now turn the experimental setting on with the person's yes, but the browser sign-in still needs the person, so 0 for autonomous onboarding, as the other harnesses that need an account were read (0). 0 + 20 + 20 + 0 = 40.

Sculptor 60

Free self-hosted software with nothing to buy, so 0 for a protocol and 20 each for public pricing, a free tier and onboarding with no sign-up, 60.

Harness 64

MIT licence for the whole repository under Autonomous, Inc., with third-party Store covers under their own licences (30). The repository documents what usage counts contain, a 10-day pseudonymous activity mark and the encrypted relay in detail. Autonomous's privacy policy of 7 July 2026 is general to its stores and sites and does not mention Harness, per the 17 October reading and the site's policy reading of 30 October (14). The provider protocol promises both revisions side by side for a deprecation window after a breaking change. Nothing similar for the app or CLI (6). Telemetry is disclosed with an opt-out in the app and CLI, but it is on by default and described in the repository rather than in the privacy policy (14). 30 + 14 + 6 + 14 = 64.

Sculptor 57

MIT (30). Consent-based telemetry documented in the repository (18 of 30). The README warns of drastic changes during the research preview, with no deprecation policy (5). Opt-in telemetry (20). 30 + 18 + 5 + 20 = 73.