MCP 服务器

reelier

Record an agent's MCP tool-call workflow once, replay it deterministically for zero tokens, and get a receipt — a snapshot-testing and deterministic-execution layer for Agent Skills.

README

Reelier

Agents make claims. Reelier writes receipts.

A dependency bump shouldn't silently break your agent. Reelier re-runs your recorded workflows against the new version at zero LLM cost and diffs them — so you see exactly what changed before you merge.

Think of it as CI + snapshot tests for your agent's tool-call workflows.

Website · Docs · SPEC.md

<sub><a href="https://www.reelier.com/reelier-explainer.mp4">▶ watch with sound (27s)</a></sub>

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Why

AI agents are non-deterministic — the same prompt, a different result every run — and they'll claim they did the work whether they did or not. Reelier records the run that worked, replays it deterministically at $0, and writes a signed receipt that proves it. Point it at your existing CI in one workflow — it adds a verifiable receipt, it doesn't replace your stack.

Measured on a real head-to-head benchmark, same task, same data (full method):

1,000 / 1,000 replays byte-identical
~50× cheaper
~59× faster

Install

npm i -g reelier && reelier init

# No Node install needed — same commands via Docker:
docker run --rm ghcr.io/seldonframe/reelier --help

reelier init scans work you've already done (Claude Code, Codex, OpenClaw) into a real skill, or falls back to a zero-setup demo with a real receipt in under 60 seconds.

How to use it

reelier init                        # 60s: record → compile → replay → your receipt
reelier run  <name>.skill.md        # replay deterministically — 0 tokens (read-only by default)
reelier diff <name>                 # SAME or DRIFTED, per step — exit 1 on drift
reelier push <name>.skill.md        # sync receipts to your ledger (opt-in)
reelier ci                          # write a workflow: drift-CI + PR receipts, one command

Record. reelier mcp --wrap "<mcp server>" proxies your tools live, or pull a session via reelier scan/from-session, or run the guided reelier init.
Compile. reelier compile turns a trace into a SKILL.md — 0 LLM calls, minimal assertions, honest gaps printed as Open questions.
Replay. reelier run replays it at Level 0 — no LLM, byte-identical, read-only by default (writes need --allow-writes).
Diff. reelier diff reports SAME or DRIFTED per step, with the failing assertion as the why — exit 1 on drift.
Log in. reelier login connects this machine to Reelier Cloud with a device code in your browser — or set REELIER_CLOUD_URL/REELIER_CLOUD_KEY for CI and self-hosting.
Push. Every run is a receipt; reelier push optionally syncs it to a ledger for a permalink and an embeddable verified-replay badge.

Already have an Agent Skill? Convert it — your skill, minus the model:

reelier compile trace.jsonl --from-skill ./my-skill/SKILL.md

Three tests, one skill

Test	Command	Answers
Determinism	`reelier run <skill.md>`	Does this still do what it did?
Recovery	`reelier run <skill.md> --fail N`	If this broke, would the skill notice and heal?
Drift	`reelier run <skill.md> --wrap "<your mcp server>"`	Has the world moved out from under this skill?

Taxonomy due to Mads Hansen's review of the launch post. Full semantics for each test, including recovery injection and manifest guardrails: docs/REFERENCE.md.

Gate Dependabot / Renovate bump PRs

Dependabot and Renovate open the PR and run your test suite — but neither knows what your agent actually does at runtime, so a dependency bump that silently changes a tool call's shape (a renamed field, a new default, a different error) sails through with green unit tests. This is the check they don't run.

Copy .github/workflows/reelier-bump-check.yml into your repo, point skill: at your own recorded .skill.md file(s), and it will: gate to PRs from dependabot[bot]/renovate[bot] (or a dependencies label), install the bumped dependency, replay your recorded skill live against it at --max-level 0 (0 tokens), and fail the check on the exact step that drifted.

This tests dependency and MCP-tool-call behavior — it does not test model upgrades; --max-level 0 never calls an LLM. Full listing copy and setup: docs/marketplace-listing.md.

Prove it

A pushed receipt carries a ladder of independently-verifiable claims — not one blanket "verified." Depending on what you turn on, it can be signed, timestamped, CI-attested, and carry cross-checkable provider request-ids. reelier verify recomputes every claim offline, and a claim you haven't enabled just renders as an honest gap, never a shamed one.

See a real one: reelier.com/r/HWBdmGob9KeHRqXi-OEaRD0z.

Full 8-rung ladder, what each rung does and doesn't prove: docs/REFERENCE.md.

Who it's for

Solo dev / OSS maintainer — a real regression test again; drift can't pass silently.
Team shipping agent changes — "it ran clean" becomes a checkable PR artifact, not a claim.
Agency running agents for clients — signed, timestamped proof-of-delivery a client can verify.
Marketplace buyer or seller — corroborated receipts are reviews that can't be astroturfed.
Audit-facing ops — a signed, CI-attested trail of every write, idempotency key included.

MIT, free forever (versions ≤0.16.0 remain AGPL-3.0). Your data — skills, traces, runs — is specified in SPEC.md, so leaving is copying a folder.

Contributing: issues and PRs welcome — SPEC.md is the source of truth for formats; fix the code, not the spec. npm test before a PR.

If Reelier saved you a re-run, star it ⭐ — it's how other builders find it.

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