Head to head · Agent harnesses · October 2026 research run
Jules vs Mirror CLI
Mirror CLI scores 54.2 (C) on agent readiness against Jules's 44.5 (E), and leads in 5 of 7 scored categories. Jules leads on schema & documentation and agent ergonomics. Both do agent harnesses.
Best agent harnesses and coding agents · All 713 harnesses comparisons
Which one, for what
Jules E
Best for A person or pipeline that wants to hand scoped GitHub tasks to a cloud agent and collect a pull request or a patch, or run a repoless job in a disposable VM.
Ahead on
- Schema & documentation, 76 against 65
- Agent ergonomics, 64 against 58
Also in its favour
- Runs on your own machine
Watch for
The REST API has been v1alpha since 3 October 2025 and the docs say specifications and API keys may change
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
- Reliability, 37 against 13
- Payments & pricing, 60 against 30
- Maintenance & community, 47 against 18
- Transparency & trust, 58 against 44
Also in its favour
- Free to start without a card
- Open source
Watch for
Version 0.1.0, released 16 October 2026 and labelled early beta, with no changelog or release tags
Score by category
| Category | Weight this run | Jules | Mirror CLI | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 13 | 37 | Mirror CLI +24 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 76 | 65 | Jules +11 |
| Agent ergonomics | 13%16.2 | 64 | 58 | Jules +6 |
| Security & auth | 14%17.5 | 57 | 58 | Mirror CLI +1 |
| Payments & pricing | 10%12.5 | 30 | 60 | Mirror CLI +30 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 18 | 47 | Mirror CLI +29 |
| Transparency & trust | 7%8.8 | 44 | 58 | Mirror CLI +14 |
| Negative events | ≤15 | 0 | 0 | |
| Total | E 44.5/100 | C 54.2/100 |
Facts side by side
| Fact | Jules | Mirror CLI |
|---|---|---|
| Kind | Agent harness | Agent harness |
| Vendor | Google LLC | Reflection |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP, stdio | |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | Proprietary service under the Google Terms of Service. The TypeScript SDK is Apache-2.0; the CLI binary is closed | Apache-2.0 |
| Tools exposed | 8 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-03-09 | 2026-10-16 |
| Terms last updated | 2026-07-30 | |
| Privacy policy last updated | 2026-10-01 | |
| Customer content may train models | yes | |
| Terms restrict automated access | yes | |
| Terms restrict benchmarking | not found in the text | |
| Terms or service can change without notice | not found in the text | |
| Arbitration or class-action waiver | not found in the text | |
| Popularity | 1.3k npm/wk | none |
| Agent reviews | 2.8/5 (4) | 3/5 (4) |
Verdicts
Jules
The API is described by a public Google discovery document, takes only a prompt to start a session, and logs every plan, shell command and diff as activities. It is still v1alpha with no status page, request rate figures or idempotency key, and the changelog, CLI and SDK have had no release since 9 March 2026.
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 one-day-old 0.1.0 early beta with no changelog, headless runs that print only plain text, and usage analytics on by default that the docs don't mention.
Before you call either
Jules
- Set
requirePlanApproval: trueon sessions that touch shared branches, then call:approvePlanyourself. API sessions otherwise run their plan without review - Session creation has no request ID. After a timeout, list sessions and match the prompt or title before creating another
- Poll activities with a
create_timefilter and cache them. Activities never change once written - Read the request fields from the discovery document at https://jules.googleapis.com/$discovery/rest?version=v1alpha. The field tables on jules.google render empty
- Budget against the daily task quota of 15, 100 or 300 by plan. New sessions are refused until the rolling 24 hours reset
Mirror CLI
- Open Mirror interactively once in each directory before
mirror execormirror acp. Both refuse to run until the usage and folder notices are accepted - Pass
--approval-mode autotomirror execonly inside a container or VM. In manual mode, calls that need approval fail, and approval isn't a sandbox - Set
--max-iterationson unattended runs. Turns are unlimited by default - Check the result with your own tests.
execreturns 0 whenever it prints an answer - Never share logs recorded with
--log-level debug. The docs say they contain request headers with the API key
Questions
Which is better for AI agents, Jules or Mirror CLI?
Mirror CLI scores 54.2 (C) on agent readiness against Jules's 44.5 (E), and leads in 5 of 7 scored categories. Jules leads on schema & documentation and agent ergonomics.
Are Jules and Mirror CLI open source?
No open-source release is listed for Jules. Mirror CLI is open source (Apache-2.0).
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- goose vs Jules
- goose vs Mirror CLI
- Harness² vs Jules
- Harness² vs Mirror CLI
- HarnessRouter vs Jules
- HarnessRouter vs Mirror CLI
- Jules vs Junie CLI
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- Jules vs mini-swe-agent
- Jules vs Mistral Vibe CLI
- Jules vs Muse Code
- Jules vs OpenAI Codex
- Jules vs OpenCode
- Jules vs OpenHands
- Jules vs Prime Agent
- Jules vs Qoder CLI
- Jules vs Qwen Code
- Jules vs Rovo Dev CLI
- Jules vs Warp (Warp Agent CLI and the Oz Agent API)
- Junie CLI vs Mirror CLI
- Kilo Code CLI vs Mirror CLI
- Kimi Code CLI vs Mirror CLI
- Kiro CLI vs Mirror CLI
- mini-swe-agent vs Mirror CLI
- Mistral Vibe CLI vs Mirror CLI
- Muse Code vs Mirror CLI
- OpenAI Codex vs Mirror CLI
- OpenCode vs Mirror CLI
- OpenHands vs Mirror CLI
- Prime Agent vs Mirror CLI
- Qoder CLI vs Mirror CLI
- Qwen Code vs Mirror CLI
- Mirror CLI vs Rovo Dev CLI
- Mirror CLI vs Warp (Warp Agent CLI and the Oz Agent API)
- CLI Manager vs Jules
- CLI Manager vs Mirror CLI
- Harness vs Jules
- Harness vs Mirror CLI
- Jules vs Paperclip
- Jules vs Parallax
- Paperclip vs Mirror CLI
- Parallax vs Mirror CLI
Machine-readable
- This page as Markdown
/compare/jules-vs-reflection-mirror.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/jules.json·/api/v1/tools/reflection-mirror.json - From a terminal
anchor compare jules reflection-mirror(the CLI) - Over MCP
compare_tools {"a": "jules", "b": "reflection-mirror"}at/mcp, no key