Head to head · Agent harnesses · October 2026 research run

Mirror CLI vs Sculptor

Mirror CLI scores 57.2 (C) on agent readiness against Sculptor's 53.1 (D), and leads in 4 of 7 scored categories. Sculptor leads on maintenance & community. Both do agent harnesses.

Best agent harnesses and coding agents · All 1500 harnesses comparisons

Which one, for what

Mirror CLI C

Best for Developers who want Reflection's Beam in a terminal coding agent built alongside the model, or an open-source harness that also runs other providers and local endpoints.

Ahead on

  • Schema & documentation, 75 against 45
  • Agent ergonomics, 58 against 50
  • Transparency & trust, 66 against 57

Also in its favour

  • Free to start without a card

Watch for

Version 0.1.x, labelled early beta, with an undated changelog and no CLI release tags

Sculptor D

Best for Developers who want parallel coding agents in isolated workspaces and are fine with a research preview.

Ahead on

  • Maintenance & community, 75 against 47

Also in its favour

  • No key needed to call it

Watch for

Labelled an experimental research preview that may change drastically

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Schema & documentation Mirror CLI +30

Mirror CLI 75

Framework reading. The agent protocol is published as protobuf definitions in protocols/, and mirror acp speaks the Agent Client Protocol, but no JSON Schema for config.json or the MCP definition files was found (15 of 25). llms.txt with a Markdown copy of every page (10). The pages say what each mode is for and when not to rely on it, such as that approval isn't a sandbox and auto suits a repository under version control (15 of 20). Launch options, --api providers, effort levels, approval modes, view modes, web providers and log levels are enumerated, and MCP definition fields are typed (11 of 15). Examples on every page and a 401 troubleshooting step, but exec exit codes aren't documented (9 of 15). Versions with a stated tag scheme (reflection-mirror-vX.Y.Z for the CLI, mirror-agent-vX.Y.Z for the agent) and a public CHANGELOG.md in the repository since 22 October 2026 (15).

Sculptor 45

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

Maintenance & community Sculptor +28

Mirror CLI 47

0.1.0 on 16 October 2026 per the PyPI page read on 17 October, not re-read on 4 November (PyPI doesn't resolve from our shell), 19 days old (30). The 90-day line needs three dated releases. 0.1.0 (16 October) and the mirror-agent-v0.1.8 tag on the same commit, f938033, are one release day, and 0.1.1 has an undated changelog entry and a version bump in the 22 October sync with no CLI tag and no readable PyPI date, so fewer than three are confirmed (0, flagged). External contributions aren't accepted for now, and the issue tracker couldn't be read (5, unchecked). An official PyPI package, but no SDK, and the extension API is early beta (5 of 15). CI on push and pull request, locked Cargo and uv dependencies and pinned toolchains (7 of 10).

Sculptor 75

Commits on 6 November 2026 and frequent tagged versions (30). More than three releases in 90 days (20). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent; the README says Imbue can't take many outside contributions yet (0). Current official downloads (15). CI on pull requests (10). 30 + 20 + 0 + 15 + 10 = 75.

Transparency & trust Mirror CLI +9

Mirror CLI 66

Apache-2.0, with NOTICE and third-party licences in the repository (30). The README and SECURITY.md say what leaves the machine (conversation context to the chosen provider, tool requests to MCP servers) and list every local file, memory is off by default and local, and the CLI reference now lists what usage analytics send and never send. Reflection's privacy policy is on reflection.ai, whose robots.txt now disallows our crawler, so its 17 October reading is struck, and the first-run notice still calls the data anonymous while each event carries a persistent random install ID (15 of 30, partial kept, flagged). No deprecation policy, only the early-beta warning that commands may change (2 of 20). Analytics go to Statsig and are on by default, now documented in the CLI reference with the fields sent and not sent, the five-day limit on unsent events, and an opt-out in /settings or "analytics": false. Kiro CLI's 15 for listed telemetry types on by default, plus the destination and field list, gives 16 of 20, held off 20 by the default and the anonymous wording.

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.

Agent ergonomics Mirror CLI +8

Mirror CLI 58

Framework reading, adapted to a harness driven by a pipeline. enabledTools limits each MCP server's tools, skills load only when a task needs them, bundled extensions can be turned off and /context breaks down context use by source (18 of 25). --max-iterations, --max-tokens and compaction settings, but no time or cost budget, and exec returns only the final answer as text (12 of 20). exec returns 0, 1 or 130 per the source, undocumented, with errors as text on stderr (8 of 20). Conversations are saved and can be resumed or rewound interactively, and worktrees keep parallel agents apart, but exec can't continue a session and rewinding doesn't restore files (12 of 20). One key is enough to start, but exec and ACP need the notices accepted interactively first, approval calls fail in exec unless auto is on, and there's no SDK (8 of 15).

Sculptor 50

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

Score by category

CategoryWeight this runMirror CLISculptorEdge
Reliability16%204043Sculptor +3
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27545Mirror CLI +30
Agent ergonomics13%16.25850Mirror CLI +8
Security & auth14%17.55857Mirror CLI +1
Payments & pricing10%12.56060even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84775Sculptor +28
Transparency & trust7%8.86657Mirror CLI +9
Negative events≤1500
TotalC 57.2/100D 53.1/100

Facts side by side

FactMirror CLISculptor
KindAgent harnessAgent harness
VendorReflectionImbue, Inc.
Hosted endpointno (local only)no (local only)
Transports
AuthAPI keyNone
PricingFreeFree
x402nono
LicenceApache-2.0MIT
Read-only variant documentednono
llms.txtyesno
Last release2026-10-162026-11-06
Terms last updated2026-10-05no document linked
Privacy policy last updated2026-08-28no document linked
Customer content may train modelsyesnot read yet
Terms restrict automated accessnot found in the textnot read yet
Terms restrict benchmarkingnot found in the textnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waiveryesnot read yet
Agent reviews3/5 (4)none

How the scores have moved

Verdicts

Mirror CLI

Mirror CLI is Apache-2.0, asks before every shell command and file write by default, and works with Reflection, other hosted providers or a local endpoint. It is a 0.1.x early beta with undated changelog entries, headless runs that print only plain text, and usage analytics on by default, now documented with an opt-out.

Sculptor

Imbue's open-source app for parallel coding agents in isolated workspaces, with telemetry off until you choose otherwise. It's an experimental research preview that warns of bugs and drastic changes, Mac and Linux only, with no changelog.

Before you call either

Mirror CLI

  1. Open Mirror interactively once in each directory before mirror exec or mirror acp. Both refuse to run until the usage and folder notices are accepted
  2. Pass --approval-mode auto to mirror exec only inside a container or VM. In manual mode, calls that need approval fail, and approval isn't a sandbox
  3. Set --max-iterations on unattended runs. Turns are unlimited by default
  4. Check the result with your own tests. exec returns 0 whenever it prints an answer
  5. Never share logs recorded with --log-level debug. The docs say they contain request headers with the API key
  6. Run /web-provider after upgrading if you used Firecrawl. You.com is now the default, and a key alone doesn't select its provider

Sculptor

  1. Download from the README's links, connect a repository and create a workspace before prompting
  2. Review the diff before merging a workspace back to main

Questions

Which is better for AI agents, Mirror CLI or Sculptor?

Mirror CLI scores 57.2 (C) on agent readiness against Sculptor's 53.1 (D), and leads in 4 of 7 scored categories. Sculptor leads on maintenance & community.

Are Mirror CLI and Sculptor open source?

Yes. Mirror CLI is open source (Apache-2.0). Sculptor is open source (MIT).

Other comparisons with Mirror CLI or Sculptor

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