Browse reusable Agent Skills, each with a clear purpose and practical guidance.
Debug a user-reported issue, Linear ticket, or incident report by combining Datadog (APM, logs, metrics) with the Langfuse repo to establish a root cause. Use when given a Linear issue URL/ID (e.g. LFE-XXXX), a GitHub issue, or a pasted error/report and asked to investigate, root-cause, or triage. Produces a structured analysis — error breakdown, hypothesis-by-class, suggested patches with code references.
Look up, compare against, and (after human approval) update the Linear incident-alert knowledge base: one ticket per production alert/monitor, labeled `incident-alert`, with one dated cause section per distinct root cause. Use whenever an investigation is anchored to a named alert identity — a Datadog monitor ID or title, an incident.io alert/INC reference, or an on-call page — both before debugging from scratch (a documented cause may already answer it) and after establishing a new root cause (record it).
Refactor avoidable React useEffect usage in Langfuse frontend code. Use when adding, reviewing, or removing effects; initializing forms or local UI state from query data; synchronizing client and server state; moving mutations or async workflows out of components; cleaning every effect from a frontend submodule; or reviewing whether an effect has a valid external-system owner.
Seed local Langfuse test data with one command: large/branching observation trees (v3 and v4 events), long sessions, bulk traces for list performance. Use whenever a task needs ClickHouse/Postgres test data — e.g. "seed a complex trace", "make a tough session", "fill the trace list", "test v4 events UI", or when debugging trace/session/list rendering or performance. Never write ad-hoc seed scripts or raw ClickHouse inserts.
Prepare Langfuse weekly production reviews that audit what broke, what was fixed, what remains open, and where Datadog, incident.io, or Linear tracking needs cleanup. Use when asked for a production review, "what broke last week", fixed/open production bugs, Datadog alerted monitors/pages, Datadog error log patterns, incident.io incidents, incident.io alert load, pager load by engineer or time of day, or a source-table engineering review across incident.io, Linear bugs, Datadog alerts, and Datadog logs.
Decide whether open Bug PRs target the correct branch. A bug must be fixed on the lowest maintained branch where it exists, then merged up. Use when the user says "triage bug PRs", "which PRs need retargeting", or "retarget triage".
Decide whether a recurring hardening invariant is worth a CI gate, and add it without hitting the traps. Covers PHPStan custom rules (implementation-shape checks) and the check-hardening-tests.php convention (test-presence checks). Use when the user says "write a PHPStan rule", "add a hardening rule", "gate this pattern", "catch this in CI", or wants to turn a finding into a durable check.
Cascade-merge maintained Symfony branches from oldest to newest (e.g. 6.4 → 7.4 → 8.0 → 8.1). Use when the user says "merge branches", "merge up", "cascade merge", "sync branches", or "update branches".
Review a change (a PR, the current branch diff, or a set of files) or audit a component or the whole tree for missing or incorrect security hardening. Reasons about trust boundaries from first principles, then checks the code against Symfony's hardening-invariant families and runs the .github/sa-tools gates. Use when the user says "security review", "security audit", "check hardening", "review this PR/branch for security", "audit <component> for <vuln class>", "is any hardening missing", or names a vulnerability class to hunt for.
Triage a reported security finding into a disposition: a private CVE (coordinated disclosure + advisory), a public hardening PR (fix in the open, no CVE), or not-a-security-issue (reply to reporter). Assigns severity and affected maintained branches, and routes to the next step. Use when the user says "does this need a CVE", "CVE or hardening", "triage this report", "is this a security issue", "classify this finding", or "how should we disclose this".