EAS Observe Performance Guide
Helps Expo teams instrument, query, and interpret production startup, navigation, and custom-event performance metrics.
The material clearly warns that EAS Observe is paid, discloses that events are transmitted to the cloud, prohibits PII in event data, and describes debug-build and sampling behavior. Points are deducted because least-privilege requirements, account permission boundaries, deletion/rollback procedures, and dependency security review are not documented; enabling production telemetry can create external cost and data-flow impact.
The references cover installation, SDK 55 versus 56 branching, integrations, queries, pagination, and debug limitations, with a useful warning to consult official documentation. Points are deducted because there are no committed tests, reproduced outputs, or systematic abnormal-input handling; the document acknowledges possible lag behind a changing API, so failure diagnosis remains limited.
The intended audience, scenarios, and main inputs and outputs are reasonably clear, covering startup, route, event, and version metrics and distinguishing Expo Router from React Navigation. Points are deducted for weak non-fit boundaries, trigger exclusions, and Chinese-language guidance; core operation depends on EAS accounts, login, network access, and overseas cloud services, with no evidence of mainland-China reachability.
The skill uses progressive disclosure through setup, queries, and metrics references, and includes version differences, examples, limitations, and an MIT license. Repository workflows provide some maintenance signal through version and size checks. Points are deducted because there is no skill-specific changelog, named maintenance owner, or explicit update path, and linked service documentation may drift as EAS evolves.
The skill can directly guide installation, root instrumentation, TTI marking, optional route and event instrumentation, CLI querying, and basic metric interpretation. Points are deducted because the files contain no verifiable real execution results or test coverage, and they do not establish a clear advantage over consulting the official documentation; users still need a real build, authentication, paid service access, and current API verification.
Major topics cite Expo's official documentation and include command examples, JSON shapes, and configuration snippets, providing limited auditability. Points are deducted because this is a static review with no execution reproduction, independent corroboration, or committed tests covering the skill's key paths, so current command and API correctness cannot be confirmed.
- Before enabling production telemetry, verify EAS billing, account permissions, retention terms, and organizational privacy requirements.
- Do not place personal information, tokens, or other sensitive data in event names, attribute keys or values, or event bodies.
- Check the current Expo documentation and eas CLI --help before use; no examples were executed in this assessment.
- For users in mainland China, verify network reachability for expo.dev/EAS login, ingestion, and querying services.
What does this skill do, and when should you use it?
eas-observe is an Agent Skill in the expo/skills repository dedicated to EAS Observe. It guides agents through adding expo-observe to an Expo project, configuring the root component, marking interactivity, adding route metrics, and logging custom events. It also covers five EAS CLI query commands and explains cold and warm launches, TTR, TTI, navigation timing, update downloads, and TTI frameRate parameters. EAS Observe is a paid service, and production ingestion and querying consume plan allowances.
The skill guides an agent through installing and configuring expo-observe in an Expo project, using AppMetricsRoot on SDK 55 or ObserveRoot on SDK 56 and later, calling markInteractive() or useObserve(), and configuring Expo Router, React Navigation, and Observe.logEvent integrations. It also explains how to run eas observe:metrics-summary, eas observe:metrics, eas observe:routes, eas observe:events, and eas observe:versions, interpret table or JSON output, and diagnose performance using the documented metrics and TTI frameRate parameters.
- An Expo team needs to instrument a production app for startup performance.
- A team using Expo Router or React Navigation needs cold and warm navigation timing by route.
- An engineer needs terminal access to version, event, route, or aggregate metrics.
- A performance investigator needs to distinguish slow-but-smooth startup from main-thread contention or hard blocks.
- A product or engineering team needs to assess the cost and usage implications of EAS Observe.
What are this skill's strengths and limitations?
- Covers the setup, CLI-query, and metrics-diagnosis workflow.
- Clearly distinguishes SDK 55 from SDK 56 and later integration patterns.
- Includes Expo Router, React Navigation, and custom-event use cases.
- Maintained by the official Expo team and released under the MIT license.
- Requires the paid EAS Observe service, with free-tier and usage limits.
- Its references may lag behind the evolving official documentation.
- The source provides no test suite, platform support matrix, or failure-recovery procedure.
- Its scope is EAS Observe only; sibling skills in expo/skills are not included in this profile.
How do you install this skill?
The skill is located at plugins/expo/skills/eas-observe/SKILL.md. The README does not document a command for installing only eas-observe; to install the full Expo Skills collection, run: npx skills@latest add expo/skills --skill '*'. For Codex, run: codex plugin add expo@openai-curated. For Claude Code, run: claude plugin install expo@claude-plugins-official. Restart or refresh the agent session after installation.
How do you use this skill?
In an agent session with the skill installed, ask for a concrete task such as: “Set up EAS Observe in this Expo project and show me how to query startup and route metrics.” For terminal queries, ask the agent to use eas observe:metrics-summary, eas observe:metrics, eas observe:routes, eas observe:events, or eas observe:versions. Use the official Expo EAS Observe documentation as the authority for API details.
How does this skill compare with similar options?
The README identifies Expo documentation, Expo CLI, and EAS CLI as the sources of truth. This skill is an agent-oriented application layer for that guidance, not a replacement for the official documentation or CLI.