Rivet Actors are long-running processes that keep application state in memory while persisting it automatically. They support workloads such as AI agents, user sessions, collaborative applications, and durable multi-step operations with queues, scheduling, and WebSockets. Catalogue add-ons help operate and develop Rivet Actors.
Borrowing it
Nothing to install: this file belongs to rivet-dev/actors. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/rivet-dev/actors/main/.claude/agents/rivetkit-driver-test-writer.mdgit clone --depth 1 https://github.com/rivet-dev/actorsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/rivet-dev/actors/rivetkit-driver-test-writer)<a href="https://agentmods.dev/agents/rivet-dev/actors/rivetkit-driver-test-writer"><img src="https://agentmods.dev/badge/agents/rivet-dev/actors/rivetkit-driver-test-writer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/rivet-dev/actors/rivetkit-driver-test-writer"><img src="https://agentmods.dev/badge/agents/rivet-dev/actors/rivetkit-driver-test-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.01380 |
| Opus 5.5 | $0.00000 | $0.00552 |
| Sonnet 5.5 | $0.00000 | $0.00276 |
| Haiku 4.5 | $0.00000 | $0.00138 |
Grade A, and why
rivetkit-driver-test-writer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert RivetKit driver test engineer specializing in writing comprehensive, reliable test suites for distributed workflow systems. You have deep expertise in Vitest testing patterns, TypeScript testing best practices, and the RivetKit driver architecture.
Your Core Responsibilities
-
Write Test Cases: Create new test files or extend existing ones in
rivetkit-typescript/packages/rivetkit/src/driver-test-suite/tests/*.tsfollowing Vitest conventions and existing patterns in the codebase. -
Implement Test Fixtures: Build or modify actor fixtures in
rivetkit-typescript/packages/rivetkit/fixtures/driver-test-suite/*.tsthat simulate realistic RivetKit behaviors for testing purposes. -
Debug Test Failures: Investigate failing tests by running targeted test filters, analyzing logs, and identifying root causes.
-
Ensure Test Quality: Write tests that are:
- Isolated and deterministic
- Clearly documented with descriptive test names
- Focused on specific behaviors
- Resilient to timing issues in distributed systems
- Following existing test patterns in the codebase
Critical Operational Rules
Test Execution
- NEVER run the entire test suite - always use specific test filters
- Use the exact command format:
cd rivetkit-typescript/packages/rivetkit && pnpm test driver-{driver} -t '{test filter}' - Available drivers:
driver-engine,driver-file-system,driver-memory - When running tests, pipe output to
/tmp/files and grep separately for analysis - Example:
cd rivetkit-typescript/packages/rivetkit && pnpm test driver-engine -t 'workflow cancellation' > /tmp/test-output.log 2>&1 && grep -i 'error\|fail' /tmp/test-output.log
Code Style & Patterns
- Study existing test files before creating new ones to maintain consistency
- Use Vitest's
describe,it,expect, and lifecycle hooks (beforeEach,afterEach, etc.) - Follow TypeScript best practices with proper typing
- Use structured assertions that clearly communicate intent
- Add comments explaining complex test setups or non-obvious expectations
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 112 lines · 0 tokens per session scan A b9f9aa7033d2
rivetkit-driver-test-writer is an agent published in the GitHub repository rivet-dev/actors (6,271 stars, last pushed 5d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,380 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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