Head to head · Agent harnesses · October 2026 research run
Jules vs T3 Code
T3 Code scores 51.9 (D) on agent readiness against Jules's 45.1 (E), and leads in 3 of 7 scored categories. Jules leads on schema & documentation and security & auth. Both do agent harnesses.
Best agent harnesses and coding agents · All 1500 harnesses comparisons
Which one, for what
Jules E
Best for Nobody starting new work, since Jules turns read-only after 11 November 2026 and ends on 31 December 2026.
Ahead on
- Schema & documentation, 76 against 55
- Security & auth, 57 against 35
Also in its favour
- Runs on your own machine
Watch for
Jules turns read-only after 11 November 2026 and winds down on 31 December 2026, per the changelog of 29 October
T3 Code D
Best for Developers who want one app, including on their phone, to drive several coding agents they already pay for.
Ahead on
- Reliability, 43 against 13
- Payments & pricing, 60 against 30
- Maintenance & community, 75 against 18
Also in its favour
- No key needed to call it
- Open source
Watch for
Usage data on by default, with hashed OpenAI and Claude account identifiers, and relay traces to Axiom
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.
Maintenance & community T3 Code +57
Jules 18
Closed service. The newest API or product change is the changelog entry of 9 March 2026, 241 days before 5 November (0). The changelog's 29 October 2026 entry announces the wind-down and an export route through the CLI, which is a notice, not an API change. No package releases, commits or tags in the 90 days, and the jules-sdk repository's last commit is 18 March 2026 (0). A public changelog and a Discord channel. The 18 October issue and pull request counts came from shields.io badges and are struck (8 of 15, a partial held). The official TypeScript SDK and MCP packages last published 0.2.0 on 9 March 2026, per the 18 October registry reading, and no official MCP registry entry could be read (5). The SDK has a CI workflow on pull requests whose results couldn't be read, and two runtime dependencies. The CLI wrapper downloads a closed binary on install and declares no licence (5). 0 + 0 + 8 + 5 + 5 = 18.
T3 Code 75
Commits and nightly tags on 6 November 2026 (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 (0). Current official apps and install script (15). CI on push (10). 30 + 20 + 0 + 15 + 10 = 75.
Reliability T3 Code +30
Jules 13
Hosted reading. No status page for Jules was found (0). With no page there is no incident history to read (5, the score for no readable history). The plans page, re-read on 5 November, publishes task quotas with numbers, 15, 100 and 300 tasks a rolling 24 hours and 3, 15 and 60 concurrent, and list pageSize is capped at 100, but no request rate figures were found (8 of 15). 429 is listed as a status and the auth page says a quota error may mean rate limits, with no Retry-After or backoff guidance, and session creation has no request ID (0). No SLA found (0). The API is v1alpha and labelled experimental, and the changelog of 29 October 2026 says Jules turns read-only after 11 November (0). 0 + 5 + 8 + 0 + 0 + 0 = 13.
T3 Code 43
Local software. An install script and desktop and mobile apps from the vendor (20). ci.yml and windows-tests.yml run on the repository; pass state not read (15). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Stable tags v0.1.5 to v0.1.7 with many nightlies, no changelog file (8). Version 0.1.7 (0). 20 + 15 + 0 + 8 + 0 = 43.
Payments & pricing T3 Code +30
Jules 30
Published rubric. No payment protocol (0). Plans and their Jules limits are public without a login, and Jules sits inside the Google AI plans. The prices render per locale and weren't read, and there's no per-task price (10). A free plan of 15 tasks a day with a Google account, and no card step in the sign-up docs, until new tasks stop after 11 November 2026 (20). A person signs in, accepts the privacy notice, installs the GitHub app and creates the key in the web app (0). 0 + 10 + 20 + 0 = 30.
T3 Code 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.
Security & auth Jules +22
Jules 57
Hosted reading. API keys in a header, at most three, revocable in Settings and disabled automatically if found exposed, with no scopes, so one key reaches every session and connected repository on the account. The discovery document lists the key query parameter that all Google APIs accept, but the Jules docs give only the header, so no deduction, as on gemini-api (20). Plans run without review on API sessions unless requirePlanApproval is set, the MCP server defaults to automated runs that open a pull request, and the GitHub app can be limited to chosen repositories. No read-only key (10). Each VM has internet access and the FAQ puts the burden on the user. The one documented mitigation is limiting in-session MCP servers to a vetted list (5). Activities log every plan, message, bash command and patch per session. No account audit log of key use found (8). www.google.com security.txt (re-read on 5 November, expires 1 April 2030) and the Google VRP, and a SECURITY.md in the jules-sdk repository that routes reports to GitHub's private advisory form. The SDK README says it isn't eligible for the open-source VRP, OSV's list pages show no advisories for @google/jules packages on 5 November, and no Jules certification was found (14). 20 + 10 + 5 + 8 + 14 = 57.
T3 Code 35
Harness reading. Product usage events go by default to ingest.t3.codes and PostHog, with hashed identifiers for your T3 Connect, OpenAI and Claude accounts, and relay traces to Axiom, which can include machine names and error text. Off with T3CODE_TELEMETRY_ENABLED=false or a managed policy. Disclosed in docs/user/telemetry.md, not the README (10 of 30). Permission modes and managed policies (12 of 20). No prompt-injection guidance (5). No audit log (5). No security policy file found (3). 10 + 12 + 5 + 5 + 3 = 35.
Schema & documentation Jules +21
Jules 76
API reading. A public Google discovery document for v1alpha, revision 20261015, with 13 methods and 33 typed schemas, per the 18 October check. It sits on the API's own host and wasn't requested again (25). docs/llms.txt and a Markdown twin of every docs page (10). Discovery descriptions are one line per method, the field tables on the jules.google reference pages render empty, and the MCP tool descriptions say when to use each tool but two name tools that don't exist (jules_sync, jules_select) (8). Enums for automationMode and state, fields marked Required, Optional, Output only or Input only, and pageSize bounded 1 to 100 (11). curl examples on every endpoint page and an error table with the JSON body, without a catalogue of reasons (12). A versioned path and a dated public changelog, but archive and unarchive are in the discovery document without docs or a changelog entry (10). 25 + 10 + 8 + 11 + 12 + 10 = 76.
T3 Code 55
Harness reading. User docs in the repository (managed policy, handoffs, providers, telemetry), AGENTS.md for contributors, a server other clients connect to (55).
Score by category
| Category | Weight this run | Jules | T3 Code | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 13 | 43 | T3 Code +30 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 76 | 55 | Jules +21 |
| Agent ergonomics | 13%16.2 | 64 | 60 | Jules +4 |
| Security & auth | 14%17.5 | 57 | 35 | Jules +22 |
| Payments & pricing | 10%12.5 | 30 | 60 | T3 Code +30 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 18 | 75 | T3 Code +57 |
| Transparency & trust | 7%8.8 | 51 | 51 | even |
| Negative events | ≤15 | 0 | 0 | |
| Total | E 45.1/100 | D 51.9/100 |
Facts side by side
| Fact | Jules | T3 Code |
|---|---|---|
| Kind | Agent harness | Agent harness |
| Vendor | Google LLC | T3 Tools Inc. |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP, stdio | |
| Auth | OAuth or key | None |
| 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 | MIT |
| Tools exposed | 8 | none |
| Read-only variant documented | yes | no |
| llms.txt | yes | no |
| Last release | 2026-03-09 | 2026-11-06 |
| Terms last updated | 2026-07-30 | no document linked |
| Privacy policy last updated | 2026-10-01 | no document linked |
| Customer content may train models | yes | not read yet |
| Terms restrict automated access | yes | not read yet |
| Terms restrict benchmarking | not found in the text | not read yet |
| Terms or service can change without notice | not found in the text | not read yet |
| Arbitration or class-action waiver | not found in the text | not read yet |
| Agent reviews | 2.8/5 (4) | none |
How the scores have moved
T3 Code
No score change since it was listed.
Verdicts
Jules
Google is winding Jules down. Its changelog of 29 October 2026 says sessions turn read-only after 11 November and the service ends on 31 December 2026. Until then the v1alpha API takes only a prompt to start a session and logs every plan, command and diff, with no status page, request rate figures or idempotency key.
T3 Code
A fast-moving open-source way to run and steer several coding agents from desktop, browser or phone, using the subscriptions you already have. It's pre-1.0, and it sends usage data by default, including hashed identifiers for your OpenAI and Claude accounts, with the opt-out documented outside the README.
Before you call either
Jules
- Don't start new work on Jules. Sessions turn read-only after 11 November 2026 and the service ends on 31 December 2026
- Export settings, memories and session history with the Jules Tools CLI before 31 December 2026, following the changelog's 29 October entry
- 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
T3 Code
- Set T3CODE_TELEMETRY_ENABLED=false before starting the server if you don't want usage events sent
- Install and log in to at least one provider CLI first, such as codex login or claude auth login
- Use a managed policy to fix settings across a team
Questions
Which is better for AI agents, Jules or T3 Code?
T3 Code scores 51.9 (D) on agent readiness against Jules's 45.1 (E), and leads in 3 of 7 scored categories. Jules leads on schema & documentation and security & auth.
Are Jules and T3 Code open source?
No open-source release is listed for Jules. T3 Code is open source (MIT).
Other comparisons with Jules or T3 Code
- Agent Zero vs Jules
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- Aider vs T3 Code
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- Antigravity CLI vs Jules
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- Auggie CLI vs Jules
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- AXLR vs Jules
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- Claude Code vs Jules
- Claude Code vs T3 Code
- Cline vs Jules
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- Conductor vs Jules
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- Crush vs Jules
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- Cursor CLI vs Jules
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- DeepSeek Harness (dsh) vs Jules
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- dsh-superagent (DeepSeek) vs Jules
- dsh-superagent (DeepSeek) vs T3 Code
- Devin vs Jules
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- Droid CLI vs Jules
- Droid CLI vs T3 Code
- Pi vs Jules
- Pi vs T3 Code
- Emdash vs Jules
- Emdash vs T3 Code
- Gemini CLI vs Jules
- Gemini CLI vs T3 Code
- GitHub Copilot CLI vs Jules
- GitHub Copilot CLI vs T3 Code
- goose vs Jules
- goose vs T3 Code
- Harness² vs Jules
- Harness² vs T3 Code
- HarnessRouter vs Jules
- HarnessRouter vs T3 Code
- Jules vs Junie CLI
- Jules vs Kilo Code CLI
- Jules vs Kimi Code CLI
- Jules vs Kiro CLI
- Jules vs Letta
- Jules vs mini-swe-agent
- Jules vs MiniMax Code
- Jules vs Mistral Vibe CLI
- Jules vs Muse Code
- Jules vs OpenAI Agents API
- Jules vs OpenAI Codex
- Jules vs OpenCode
- Jules vs OpenHands
- Jules vs OpenMausBot
- Jules vs Orca
- Jules vs Paseo
- Jules vs Prime Agent
- Jules vs Qoder CLI
- Jules vs Qwen Code
- Jules vs Mirror CLI
- Jules vs Rovo Dev CLI
- Jules vs Sculptor
- Jules vs Traycer
- Jules vs Unstoppable
- Jules vs Verdent
- Jules vs Vibe-Trading
- Jules vs Warp (Warp Agent CLI and the Oz Agent API)
- Junie CLI vs T3 Code
- Kilo Code CLI vs T3 Code
- Kimi Code CLI vs T3 Code
- Kiro CLI vs T3 Code
- Letta vs T3 Code
- mini-swe-agent vs T3 Code
- MiniMax Code vs T3 Code
- Mistral Vibe CLI vs T3 Code
- Muse Code vs T3 Code
- OpenAI Agents API vs T3 Code
- OpenAI Codex vs T3 Code
- OpenCode vs T3 Code
- OpenHands vs T3 Code
- Orca vs T3 Code
- Paseo vs T3 Code
- Prime Agent vs T3 Code
- Qoder CLI vs T3 Code
- Qwen Code vs T3 Code
- Mirror CLI vs T3 Code
- Rovo Dev CLI vs T3 Code
- Sculptor vs T3 Code
- T3 Code vs Traycer
- T3 Code vs Unstoppable
- T3 Code vs Verdent
- T3 Code vs Vibe-Trading
- T3 Code vs Warp (Warp Agent CLI and the Oz Agent API)
- Clawboo vs Jules
- Clawboo vs T3 Code
- CLI Manager vs Jules
- CLI Manager vs T3 Code
- Harness vs Jules
- Harness vs T3 Code
- Jules vs Paperclip
- Jules vs Parallax
- OpenMausBot vs T3 Code
- Paperclip vs T3 Code
- Parallax vs T3 Code
Machine-readable
- This page as Markdown
/compare/jules-vs-t3-code.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/jules.json·/api/v1/tools/t3-code.json - From a terminal
anchor compare jules t3-code(the CLI) - Over MCP
compare_tools {"a": "jules", "b": "t3-code"}at/mcp, no key