The short answer
Evaluate Gemini CLI if you have a verified, approved Google organization or API route and want to assess it in a repository workflow. Evaluate Claude Code if its supported account route and review surfaces fit your work. Neither condition establishes a quality or price winner. First eliminate any option you cannot access, cannot authorize to see the code, or cannot measure within your budget.
Google's specific deprecation notice says the individual, Google AI Pro and Google AI Ultra tiers stopped serving Gemini CLI requests through consumer Google login from June 18, 2026. It explicitly leaves Code Assist Standard and Enterprise access unchanged and points affected consumers to Antigravity. This is not a notice that every Gemini CLI authentication route has closed.
The generic authentication guide still recommends personal Google login. These official pages conflict. For the affected consumer tiers, use the specific deprecation notice as the decision constraint; do not treat the generic guide as proof of entitlement. Your current account access remains UNVERIFIED until checked. Antigravity is a separate migration choice, not another name for Gemini CLI.
1. Follow the account decision tree
- Only a personal Google account or Google AI Pro/Ultra? Do not budget on the former consumer-login allowance. Review the affected tiers and migration guidance first.
- A Code Assist Standard or Enterprise license? The notice excludes those tiers from this change. Ask the administrator to verify the assigned license, project and permitted data before a trial.
- An approved Gemini API or Vertex AI route? The CLI guide documents both. Confirm the actual credential route, model availability and billing project. Do not carry consumer subscription allowances into an API estimate.
- A Claude Code account? Its authentication guide lists Pro/Max, invited Team/Enterprise users, Console and supported cloud-provider routes. Record which one is active; being able to use a chat website is not sufficient evidence for the intended coding session.
- No verified route? Stop at the documentation comparison. You do not need to install another agent or buy a subscription to use the checklists below.
2. Compare the working boundaries
| Decision | Gemini CLI | Claude Code | Acceptance check |
|---|---|---|---|
| Project guidance | GEMINI.md context files; configurable filenames and memory inspection. | CLAUDE.md and documented AGENTS.md support. | Record the instructions actually loaded, not just the files present. |
| Review surface | A CLI-centered workflow; choose your own diff and test review path. | Terminal, IDE, desktop and browser surfaces. | Hold the surface and execution location constant if you want comparable runs. |
| Isolation | Sandbox methods and profiles depend on platform and configuration. | Permission rules, modes and sandbox interaction. | Record effective filesystem and network access; do not infer isolation from a terminal UI. |
| External tools | MCP tool/server trust affects confirmation. | MCP calls can be scoped with permission rules. | Check both the agent permission and the credential's service-side authority. |
Start from an existing repository with known build commands. Gemini's /memory show exposes loaded hierarchical context. For Claude Code, verify instruction loading for the actual client and provider; do not assume a shared AGENTS.md has identical precedence across tools. Give both the same neutral task brief, then record any product-specific additions.
3. Keep permissions and MCP credentials separate
A prompt saying “read only” is a request, not an enforced security boundary. Claude Code distinguishes manual, edit-accepting and other permission modes; saved rules can affect later sessions. Before allowing an action, inspect its paths and scope rather than judging only how often the agent asks.
Gemini CLI documents one-time, tool-level and server-level MCP approvals, with trusted-server configuration able to bypass confirmation. A server-wide allowance is broader than one tool call. Inventory the tools and credentials before granting trust; a connector that can read a ticket may also expose write operations.
Gemini's macOS permissive-open sandbox profile restricts writes while allowing broad reads and network access. “Sandbox enabled” therefore does not establish that secrets cannot be read or data cannot leave the machine. Record the actual backend and profile. Do not assume a local sandbox restricts what a remote MCP service can do with its credentials.
Our suggested trial uses synthetic data, disposable repository copies and no production credentials. Keep optional MCP integrations disabled until the task needs them; then use narrowly scoped test credentials. Stop if an unexpected login, external write, deployment or permission expansion is required. Vendor safety documentation is useful configuration evidence, not our independent security test.
4. Record a billable route, not a free-versus-paid slogan
There is no responsible fixed price-per-feature claim without a workload. Record the account route first, then the selected model, retries and usage. A subscription charge and metered API usage are different ledger entries; include incremental usage without counting the same included allowance twice.
Claude Code's /usage documentation distinguishes subscription usage from its locally computed API cost estimate. The estimate is not the authoritative bill; reconcile API charges against the Console or relevant provider billing record. For Gemini, match the usage record to the approved API or organization route you established above. If attribution is missing, write UNKNOWN, not zero.
| Field | What to record |
|---|---|
| Account and scope | Client version, surface, provider, plan or billing project, model, task ID and dates. Never copy secrets. |
| Fixed cost | Subscription charge and your declared allocation method; separate sunk cost from extra cash needed for the trial. |
| Variable cost | Reported input/output and cached usage where available, extra credits, retries and external service charges. |
| Billing evidence | Usage export or invoice reference, currency, tax treatment and reconciliation status. Missing amount = UNKNOWN. |
| Human work | Setup, clarification, review and repair minutes separately; do not claim they were saved without a baseline. |
| Accepted output | Passing checks, reviewed diff and remaining defects. Keep failed runs in the record. |
If you are comparing hosted app builders instead of repository agents, use the build-to-launch budget guide. Hosting, databases and deployed-app AI belong in that wider operating budget.
5. Authorize a same-task trial only if a question remains
This is a proposed experiment, not a run we completed. Example task: add an empty-result state to an existing searchable list without changing its filters. Use two disposable copies of the same commit, identical dependencies and the same acceptance criteria. Require passing baseline checks before either agent starts.
- Set the permitted files, time and spending limits, and a stopping condition before the run.
- Record effective context, model, permissions and integrations. Do not remove safeguards to improve a timing score.
- Inspect the complete diff, run project checks and verify empty-state behavior and keyboard access. Record unrelated edits and failed attempts.
- Rehearse recovery of the local change. Git recovery does not undo a database write, sent message or deployment.
- Compare review effort and attributable cost only for accepted results. Repeat on representative work before generalizing.
Keep your existing tool if the documentation review reveals no concrete gap. Read the Gemini CLI profile and Claude Code profile for dated vendor changes. For an editor-centered decision, see Cursor vs Claude Code. We have not installed either product or run a benchmark for this article; quality, speed and cost winners remain UNKNOWN.