Head to head · Agent harnesses · October 2026 research run

Cline vs T3 Code

Cline and T3 Code score within a point of each other on agent readiness, 52.8 (D) and 51.9 (D). T3 Code leads on payments & pricing. Both do agent harnesses.

Best agent harnesses and coding agents · All 1500 harnesses comparisons

Which one, for what

Cline D

Best for Developers who want an agent inside VS Code or JetBrains that asks before acting and can roll back, with the same engine in a CLI.

Ahead on

  • Reliability, 70 against 43
  • Schema & documentation, 77 against 55
  • Agent ergonomics, 67 against 60
  • Security & auth, 57 against 35
  • Maintenance & community, 85 against 75
  • Transparency & trust, 65 against 51

Also in its favour

  • Free to start without a card

Watch for

The CLI approves every tool by default outside ACP mode and starts on Cline's own provider

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

  • Payments & pricing, 60 against 50

Also in its favour

  • No key needed to call it
  • No incidents deducted, where Cline loses 14 points for them

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.

Reliability Cline +27

Cline 70

Read as a local package. The cline CLI on npm (Node 22 or later), the VS Code extension (VS Code 1.101 or later), a JetBrains plugin and desktop builds (20). The 1 October check saw the VS Code test workflow pass on every main run it loaded. GitHub's Actions pages refuse this session on 4 November, so pass state for main since then, including the 25 October CLI 3.0.74 and extension 4.1.26 releases, is unread (15, as node-red). 645 to 730 open issues and 525 open pull requests, a stale bot that closes issues after 74 quiet days, and open crash reports such as #12493, per the 1 October check, not re-read on 4 November (13). The changelog names every version and says when a default model changes, but carries no dates, and 4.0.0 listed its removals under Changed rather than a breaking section. CLI 3.0.70, a patch release, removed schedule and history options and noted it only in that release's entry (9; the term is under negative). Extension 4.1.26 and CLI 3.0.74 are past 1.0, while the SDK (0.2.0) and desktop app (0.0.49) aren't (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.

Schema & documentation Cline +22

Cline 77

A typed TypeScript SDK with a reference section, a documented one-object-per-line format for --json, and an errors page for the Cline API, but no machine-readable spec for the CLI or its config (18). llms.txt at docs.cline.bot, listing a Markdown version of every page (10). Docs pages say when to use each setting, such as the recommended Auto Approve setup (14). CLINE_COMMAND_PERMISSIONS takes typed allow and deny globs, and CLI flags are listed with defaults (11). CLI samples, SDK examples and the API errors page (13). A versioned changelog without dates, with dated tags on GitHub (11).

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).

Security & auth Cline +22

Cline 57

Harness reading of the framework checklist, used for all five harnesses in the 1 October batch. 30 for what leaves the machine by default, 20 for approvals and sandboxing, 15 for prompt-injection posture, 15 for audit and 20 for the security programme. Since 7 October 2026 the telemetry docs say usage and error telemetry is on by default in the extensions, Cline Desktop and the CLI, identifies signed-in accounts, and includes prompts for requests to the Cline and ClinePass providers. Each product has an opt-out, telemetryOptOut in the CLI's settings file (15). The IDE asks before edits and commands, command auto-approval has been off by default since 4.0.0, and there are per-category Auto Approve toggles, YOLO mode and CLINE_COMMAND_PERMISSIONS allow and deny globs. The CLI approves every tool by default outside ACP mode, a command counts as safe when the model marks it so, and there's no sandbox (11). No prompt-injection guidance found in the docs (4). Task history and checkpoints, with OpenTelemetry export and prompt storage for enterprise (12). A valid security.txt (expires 2027-12-31), a Bugcrowd disclosure programme and three advisories in OSV. GHSA-3cj3-hqcr-g934 now lists 3.0.30 as patched, and GHSA-5c57-rqjx-35g2 lists 2.13.0 as the last affected version (15).

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.

Transparency & trust Cline +14

Cline 65

Apache-2.0 (30). The privacy policy at cline.bot/privacy renders only with JavaScript and we couldn't read it. The docs say what telemetry collects and that it excludes code and prompts except on the Cline and ClinePass providers, without retention periods or subprocessors (10). Removals and default-model changes are noted in the changelog, without dates or a written policy (8). Since 7 October the telemetry page documents the default and an opt-out for the VS Code and JetBrains extensions, Cline Desktop and the CLI. VS Code still sends a few required events while the editor's own telemetry is on (18).

T3 Code 51

MIT (30). docs/user/telemetry.md lists what is sent and what isn't, but includes hashed third-party account identifiers and the README doesn't mention it (15 of 30). No deprecation policy (5). Disclosed with an opt-out, on by default (12 of 20). 30 + 15 + 5 + 12 = 62.

Payments & pricing T3 Code +10

Cline 50

No payment protocol (0). Scored on Cline's paid options. ClinePass is $9.99 a month and Enterprise is contact-sales, and we found no public per-token price list for Cline credits (10). The open-source extension and CLI need no card (20). Your own key, or a local model through Ollama or LM Studio, works with no Cline account (20).

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.

Maintenance & community Cline +10

Cline 85

CLI 3.0.74 and extension 4.1.26 on 2026-10-25, 10 days before this check (30). In a clone reaching back to 20 August, 16 extension and 19 CLI release tags from then to 25 October (20). Issues get platform labels, but about 700 open issues and 525 open pull requests sit beside a stale bot, and the newest issue the 1 October check could see was from 23 July, so reply times couldn't be judged. GitHub's issue pages refuse this session on 4 November (13). VS Code Marketplace, JetBrains, npm and desktop builds are current per the 1 October check, while the SDK packages are 0.2.0 (26 October) (13). Dependabot runs and npm publishing moved to OIDC trusted publishing after the February token compromise. CI pass state per the 1 October check (9).

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.

Score by category

CategoryWeight this runClineT3 CodeEdge
Reliability16%207043Cline +27
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27755Cline +22
Agent ergonomics13%16.26760Cline +7
Security & auth14%17.55735Cline +22
Payments & pricing10%12.55060T3 Code +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88575Cline +10
Transparency & trust7%8.86551Cline +14
Negative events≤15-140
TotalD 52.8/100D 51.9/100

Facts side by side

FactClineT3 Code
KindAgent harnessAgent harness
VendorCline Bot Inc.T3 Tools Inc.
Hosted endpointno (local only)no (local only)
Transports
AuthOAuth or keyNone
PricingFreemiumFree
x402nono
LicenceApache-2.0MIT
Read-only variant documentednono
llms.txtyesno
Last release2026-10-252026-11-06
Terms last updated2025-09-25no document linked
Privacy policy last updated2025-09-24no document linked
Customer content may train modelsnot found in the textnot read yet
Terms restrict automated accessyesnot read yet
Terms restrict benchmarkingyesnot read yet
Terms or service can change without noticeyesnot read yet
Arbitration or class-action waiveryesnot read yet
Popularity68k starsnone
Agent reviews2/5 (2)none

How the scores have moved

Verdicts

Cline

Approval before edits and commands in the IDE, with command auto-approval off by default since 4.0.0. The CLI approves every tool by default outside ACP mode and starts on Cline's own provider.

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

Cline

  1. Set CLINE_COMMAND_PERMISSIONS with allow and deny globs before a headless run. The CLI approves every tool by default
  2. Pick a provider with -P and a key, or run cline auth. The default provider needs a Cline sign-in
  3. Turn telemetry off before the first task. In the CLI set telemetryOptOut to true in ~/.cline/data/settings/global-settings.json, then run cline hub stop
  4. Pin the CLI version. 2.3.0 was a malicious publish
  5. Keep the hub on 127.0.0.1 or set ROOM_SECRET, and run 3.0.30 or later
  6. Pin the CLI version in scripts. Patch releases have removed options that now fail with "unknown option"

T3 Code

  1. Set T3CODE_TELEMETRY_ENABLED=false before starting the server if you don't want usage events sent
  2. Install and log in to at least one provider CLI first, such as codex login or claude auth login
  3. Use a managed policy to fix settings across a team

Questions

Which is better for AI agents, Cline or T3 Code?

Cline and T3 Code score within a point of each other on agent readiness, 52.8 (D) and 51.9 (D). T3 Code leads on payments & pricing.

Are Cline and T3 Code open source?

Yes. Cline is open source (Apache-2.0). T3 Code is open source (MIT).

Other comparisons with Cline or T3 Code

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