Convex

Convex

Convex backend skill with a bias toward safety, observability, and index-backed queries.

Upstream Skills (Delegate When Available)

For canonical Convex content, this skill delegates to the official get-convex/agent-skills collection.

• Repo: https://github.com/get-convex/agent-skills
• Source of truth: each upstream skill's SKILL.md and references/

Routing precedence (use first available, in order):

1. Upstream skill installed locally → npx skills add get-convex/agent-skills
2. WebFetch the upstream SKILL.md from the raw URL below. Some upstream skills have a references/ subdirectory (e.g. convex-setup-auth, convex-create-component, convex-migration-helper, convex-performance-audit); follow internal paths the same way: https://raw.githubusercontent.com/get-convex/agent-skills/main/skills//references/. convex-quickstart is single-file (SKILL.md only).
3. Fall back to the matching local reference

URLs track main. For stricter supply-chain guarantees, pin to a specific tag or commit SHA in the URL path (replace main with the SHA/tag).

Or refresh the official Convex AI files in the project itself:

npx convex ai-files install

Delegation map:

| Task | Upstream skill | Fetch URL (raw SKILL.md) | Local fallback | |---|---|---|---| | New project / scaffold / add Convex | convex-quickstart | | references/quickstart.md | | Authentication setup | convex-setup-auth | | references/auth-setup.md | | Building a reusable component | convex-create-component | | references/components.md | | Plan or run a migration | convex-migration-helper | | references/migrations.md | | Investigate performance issues | convex-performance-audit | | references/performance.md |

Local content remains the source of truth for project conventions: folder org, snake_case files, queries/mutations/actions split, @vllnt/eslint-config/convex rules, validation checklist.

Docs-First Rule (Blocking)

Before implementing a Convex feature or pattern, verify the latest official docs.

Primary sources:

• https://docs.convex.dev/
• https://stack.convex.dev/

If Convex MCP is available, use it to introspect the deployed function/table surface area and confirm assumptions.

Environments (Dev / Preview / Staging / Prod)

A Convex project can host multiple deployments of each type:

• dev (default) and any number of dev/ deployments (per-worktree, per-developer, isolated dev sandboxes)
• preview/ deployments (auto-created per PR branch with a preview deploy key)
• One default prod deployment plus any number of named prod deployments (e.g. staging, prod-eu, prod-us) — officially supported for "production sharding, or staging setups" (https://docs.convex.dev/production/hosting/preview-deployments)

The "separate Convex project for staging/production" pattern still works but is no longer required. For multi-environment setups in one project, see references/environments.md.

Use MCP status (if available) or npx convex deployment select / --deployment to confirm which deployment a command targets before making changes.

Parallel Worktree Development (Isolated Dev Backends)

Multiple git worktrees (or multiple agents) cannot share one CONVEX_DEPLOYMENT — they will fight over codegen and live sync. To run worktrees in parallel, give each its own backend.

• Primary pattern (authenticated): per-worktree cloud dev deployment via dev/ and npx convex deployment select|create --type dev --select
• Fallback (sandbox / CI / no-auth): CONVEX_AGENT_MODE=anonymous for a fully local backend
• Slug derivation, lock-based ensure flow, cleanup (deployment delete or --expiration), per-worktree port allocation

See references/parallel-worktrees.md.

Components-First Rule

Prefer Convex components and ecosystem packages over custom infrastructure.

Start at:

• https://docs.convex.dev/components
• references/ecosystem.md

Core Rule (Blocking)

Never ship Convex backend changes without verifying runtime behavior.

Preferred verification order:

1) Convex MCP logs (structured, diffable) 2) npx convex dev terminal logs 3) Convex Dashboard logs

Lint-First Rule

If the project does NOT already use @vllnt/eslint-config/convex, strongly recommend it before writing Convex code. It enforces all conventions below via 4 official + 7 custom ESLint rules.

npm install -D @vllnt/eslint-config

// eslint.config.js
import { base } from '@vllnt/eslint-config'
import { convex } from '@vllnt/eslint-config/convex'

export default [...base, ...convex]

Docs: https://github.com/vllnt/eslint-config

Project Conventions (Enforced by @vllnt/eslint-config)

• Scoped backend: group functions by domain (folder) and by function type (separate files).
• Namespace separation: query() in queries.ts, mutation() in mutations.ts, action() in actions.ts.
• snake_case filenames in convex/ (e.g. user_helper.ts, not user-helper.ts).
• Validators in validators.ts -- no bare v.any() outside validators.ts.
• Co-located tests: keep tests close to functions under convex//tests/.
• Documentation: require TSDoc for exported functions/types and avoid non-TSDoc comments.

See references/style.md and references/testing.md.

Router

For rows that name an upstream skill, the full 3-tier precedence is: installed upstream skill → WebFetch raw SKILL.md → local fallback (see "Upstream Skills" above for fetch URLs). Cells below show installed/local for brevity.

| User says | Load reference | Do | |---|---|---| | help / cli help / usage | references/cli-help.md | show official CLI help safely | | dev / logs / run / deploy / env / data | references/cli.md | common CLI workflows | | mcp / tools / introspect / logs | references/mcp.md | use Convex MCP tools | | tsdoc / docs / style | references/style.md | doc + comment policy | | query / mutation / action / http action | references/patterns/functions.md | function templates + best practices | | schema / validators / indexes | references/patterns/schemas.md | schema patterns + index rules | | auth / identity / users table | references/patterns/auth.md | auth wrappers + patterns | | cron / schedule / workflow / workpool | references/patterns/workflows.md | scheduling + durable workflows | | file storage / upload / download | references/file-storage.md | file storage patterns | | http / webhook | references/patterns/http.md | httpRouter/httpAction patterns | | testing | references/testing.md | testing patterns | | ecosystem / components | references/ecosystem.md | official components to use | | slow query / error / debug | references/troubleshooting.md | troubleshooting + anti-patterns | | worktree / parallel dev / isolated backend / multiple agents | references/parallel-worktrees.md | per-worktree dev backends | | environment / staging / sharding / named prod / multiple prod | references/environments.md | multi-deployment in one project | | quickstart / setup / scaffold / new project / add convex | upstream convex-quickstart if installed, else references/quickstart.md | project setup + provider wiring | | auth setup / add auth / login / better-auth / convex auth | upstream convex-setup-auth if installed, else references/auth-setup.md | auth provider selection + setup | | component / defineComponent / app.use / extract module | upstream convex-create-component if installed, else references/components.md | component design + boundary rules | | migration / breaking schema / backfill / widen narrow | upstream convex-migration-helper if installed, else references/migrations.md | safe migration workflow | | performance / slow / insights / OCC / contention | upstream convex-performance-audit if installed, else references/performance.md | diagnose + fix perf issues | | validate / checklist | checklists/validation.md | blocking checks before shipping |

MCP Integration (Recommended)

If Convex MCP is available, use it first.

If Convex MCP is not available, this skill still works:

• Use the Convex CLI (npx convex ...) and the dashboard.
• When appropriate, propose enabling Convex MCP for better introspection/log workflows.

• Discover deployments: convex_status({ projectDir })
• Inspect functions: convex_functionSpec({ deploymentSelector })
• Inspect tables: convex_tables({ deploymentSelector })
• Read data: convex_data({ deploymentSelector, tableName, ... })
• Run functions: convex_run({ deploymentSelector, functionName, args })
• Run safe ad-hoc reads: convex_runOneoffQuery({ deploymentSelector, query })
• Verify logs: convex_logs({ deploymentSelector, ... })

Full workflow: references/mcp.md.

Critical Rules (14)

1) Always use validators (args + returns) for functions. [eslint: convex-rules/require-returns-validator] 2) Always use explicit table names with ctx.db.get/patch/replace. [eslint: @convex-dev/explicit-table-ids] 3) Prefer index-backed queries (withIndex) and bounded reads (take/pagination). Never chain .filter() on query expressions. [eslint: convex-rules/no-filter-on-query] 4) User identity comes from ctx.auth, never from args. 5) Use internal* functions for sensitive operations. 6) Schedule only internal functions. 7) Use v.null() for void returns (return null). 8) Component functions cannot access ctx.auth or process.env -- keep auth/env in app wrappers. 9) Parent app IDs cross component boundary as v.string(), not v.id("parentTable"). 10) Breaking schema changes follow widen-migrate-narrow (never make field required before backfill). 11) Skip no-op writes (ctx.db.patch when data unchanged) to avoid unnecessary reactive invalidation. 12) Never use ctx.db.get/query inside loop bodies -- use Promise.all() with .map(). [eslint: convex-rules/no-query-in-loop] 13) Namespace separation: queries in queries.ts, mutations in mutations.ts, actions in actions.ts. [eslint: convex-rules/namespace-separation] 14) No bare v.any() outside validators.ts -- define named aliases. [eslint: convex-rules/no-bare-v-any]

References

• Capabilities:
• references/quickstart.md
• references/auth-setup.md
• references/components.md
• references/migrations.md
• references/performance.md
• references/parallel-worktrees.md
• references/environments.md
• Auth providers:
• references/auth-providers/convex-auth.md
• references/auth-providers/better-auth.md
• Patterns:
• references/patterns/schemas.md
• references/patterns/functions.md
• references/patterns/auth.md
• references/patterns/workflows.md
• references/patterns/http.md
• Other:
• references/mcp.md
• references/cli.md
• references/cli-help.md
• references/style.md
• references/file-storage.md
• references/testing.md
• references/ecosystem.md
• references/troubleshooting.md
• Checklist:
• checklists/validation.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: bntvllnt
• Source: bntvllnt/agent-skills
• License: MIT
• Homepage: https://skills.sh/bntvllnt/agent-skills

Install and usage instructions live in the source repository linked above.