ratemyagent
Test MCP servers like production services.
RateMyAgent is a reliability scanner for MCP servers. Most evaluation asks whether a tool can do the task. This asks whether it stays reliable when operated like a production service — under load, slow dependencies, rate limits, server errors, malformed replies and dropped connections.
Experimental: an LLM adapter for Anthropic and OpenAI chat completions exists but has never been run against a live API (details), and an agent adapter has been validated against scripted agents only — see Agents (experimental).
NOTE: Read-only tools, STAGING rather than production: there's no dry-run yet. Expanding capabilities soon.
Point it at a target and it:
- Measures a baseline — latency distribution, token cost, where concurrency saturates, and whether the tools enforce their own JSON Schema.
- Injects faults — timeouts, 429s, 500s, malformed replies and refused connections, through a proxy the target cannot see.
- Studies what happened — did each disrupted operation recover, and how many calls did it cost.
Then it scores the result 0–100 against a YAML policy you control, gates CI with an exit
code, and writes an AGENTS.md fix guide you can hand straight to a coding agent.
It is built for the developer who wrote an MCP server — often with AI help — and wants to know whether it is ready before something depends on it. It tests behaviour, not source: a schema that is declared but never enforced, missing backpressure, or a retry loop that amplifies failures all show up in what the target does.
When the evidence cannot support a number, it says so instead of printing one. An
unmeasurable check comes back n/a with the reason attached and leaves the score, rather
than counting as a zero or a pass. Why that matters.
What it measures, and what it refuses to score
Five dimensions, weighted to 100. Each can decline.
| dimension | measures | declines when |
|---|---|---|
| latency 20 | p50/p95/p99, TTFT, call overhead | p99 below 100 requests — nearest-rank makes it the sample maximum |
| cost 15 | tokens, prompt bloat, $/request | the model's price is unknown. A guessed rate ends up in someone's budget |
| concurrency 15 | ramp to saturation, goodput, latency knee | always. Measured and reported, never scored — the old check compared --concurrency against itself |
| contract 15 | schema audit, one edge case per declared field | no case ran, or the crashes cannot be attributed to the input rather than to a dead session |
| behavior 35 | recovery, retry amplification, duplicate mutations, loop detection | the retry loop being measured is ours, not the target's; and duplicate mutations without --verify-tool, which is what reads the target's state — see Known limitations |
The recovery threshold is derived, not fixed. The fault injector produces
1 - fault_rate ** retries against a target that never fails — 96% at the
default rate — so a fixed floor would grade the flag rather than the target.
Every report header states the rate and the floor it implies, because two scans
at different rates are not comparable.
Targets: MCP over stdio, Streamable HTTP and SSE, plus five built-in mock profiles
that need no server. The LLM adapter is experimental, as above. Outputs: terminal
scorecard, markdown report, AGENTS.md, JSON. Every scan reproduces under --seed.
Per-probe detail is in docs/PROBES.md.
Install
Published on PyPI. Python 3.10+.
pip install ratemyagent
That gives you the engine, the mock targets, and every output format — enough to run a full scan without installing anything else. The adapters that talk to real systems need their SDKs, which are optional so you only pull what you use:
pip install 'ratemyagent[mcp]' # scan MCP servers (mcp SDK 1.x or 2.x)
pip install 'ratemyagent[anthropic]' # scan Anthropic chat completions
pip install 'ratemyagent[openai]' # scan OpenAI chat completions
pip install 'ratemyagent[all]' # all of the above
With uv: uv tool install ratemyagent for a standalone CLI, or
uv pip install 'ratemyagent[all]' into the current environment.
30 seconds, no API key
There is a built-in mock target, so you can see the whole thing work before pointing it at anything real. No key, no server, no network.
ratemyagent scan --target mock --profile degraded --requests 40 \
--concurrency 16 --fault-rate 0.3
Full output
RateMyAgent Scan Results
========================
Target: degraded-mock (mock)
Probes: 6/6 complete Duration: 9.9ms
Faults: fault rate 30%, 2 retries -> recovery floor 91.0% (derived, not the policy value)
Phase 1 baseline
Latency ................ p50 3.36s, p95 7.99s, p99 - over 40 requests (0.0% errors)
Cost ................... 647 in / 120 out tokens per request, no price known for this model
Concurrency ............ no saturation up to 16 concurrent, sustained 16
Contract ............... 15 edge cases across 3 tools: 0 rejected cleanly, 15 accepted, 0 crashed
Phase 2 chaos (fault injection)
Fault tolerance ........ 20 faults injected, 10/10 operations recovered (100%) within 2 retries, 1.30x call amplification
Phase 3 behavior analysis
Behavior ............... 10/10 disrupted operations recovered (100%) within 2 retries, 1.30x amplification (ours), 0 duplicate deliveries (ours)
actual target status
p95 latency 7.99s 5.00s FAIL
schema violations accepted 9 0 FAIL
error rate 0.0% 5.0% pass ~
contract crash rate 0.0% 0.0% pass
recovery rate 100.0% 91.0% pass ~
p99 latency - 10.00s n/a ~
cost per request - $0.1000 n/a ~
retry amplification - 2.00x n/a ~
duplicate mutations - 0 n/a ~
~ recovery rate -- 10/10 disrupted operations recovered, a
95% interval of 72.2%-100.0%, which spans the 91.0% this
fault rate produces against a target that never fails.
recovery_rate_min is scored from it regardless. Remedy:
--requests or --fault-rate.
~ error rate -- Zero failures in 40 requests bounds the
error rate at roughly 8% with 95% confidence, not at 0%.
Remedy: --requests.
~ 5 caveats on unscored rows (behavior, concurrency, cost,
latency) -- -v to show.
Score breakdown:
latency 14/20 (p95 latency was 7,988ms, policy allows at most 5,000ms)
cost -/15 (not measured against this target)
concurrency -/15 (no policy threshold reads it)
contract 8/15 (invalid inputs accepted was 9, policy allows at most 0)
behavior 35/35
Score: 81/100 (policy production-default)
Latency findings:
- p95 7.99s and 0.0% errors across 40 requests, with no
heavy tail, no unusual call overhead, and no error pattern
to report.
Cost findings:
- No cost problems found: 647 input tokens per request with
no significant fixed prefix.
Concurrency findings:
- Peak goodput is 4.4 successful req/s at 16 concurrent.
Past that, added concurrency buys latency and errors
rather than completed work.
Contract findings:
- CRITICAL 9 inputs the schema forbids were accepted with a
success response: missing_required[query],
null_required[query], wrong_type[query]. Every accepted
violation is on 'query'. The tool is not validating what
it declares, so invalid data reaches whatever it writes
to.
Fault tolerance findings:
- Injected 20 faults across 93 calls (22%): 6 server_error,
5 rate_limit, 4 connection_refused, 3 timeout, 2
malformed.
- Every one of the 10 disrupted operations recovered within
2 retries.
- Under fault the latency probe saw a 20% error rate, p95
8.03s.
Behavior findings:
- Every one of the 10 disrupted operations recovered within
2 retries. That budget is the scanner's, not the target's,
and is not configurable.
8 findings across 6 probes. Run with --output agents-md to generate a fix guide.
FAIL: score 81 meets pass threshold 75, but 2 checks failed: p95 latency, schema violations accepted.
Biggest gaps: contract (8/15), latency (14/20).
ratemyagent v1.6.2 - pip install ratemyagent - github.com/SMWundefined/RateMyAgent
How to read it:
- Actual sits next to target so the gap is the information.
n/ameans the probe could not measure this target. It is excluded from the score rather than counted as a failure.~marks a caveat about how strong the evidence is — here, that 10 disrupted operations cannot tell this target apart from the injector's own 91% floor.- The last two lines are the verdict, because that is what a CI log gets searched for. A score above the pass threshold with a failed check is still a FAIL.
The target above is a built-in mock. Before reading a behavior row on a real MCP server
the same way, see Known limitations.
Scan a real target
Scan servers you run, or have permission to test. A scan is load: it calls a tool once per request, ramps concurrency, injects faults and retries what fails.
# Your own MCP server, over stdio
ratemyagent scan --target mcp --uri "stdio://./server.py" \
--tool search --tool-args '{"query": "hello"}'
# A server you run, over Streamable HTTP
ratemyagent scan --target mcp --uri http://localhost:3001/mcp \
--header 'Authorization: Bearer $TOKEN'
Every HTTP request carries User-Agent: ratemyagent/<version> (+<repo url>) so the traffic
is identifiable in an access log, unless you pass your own --header 'User-Agent: ...'.
Five things to know before scanning something real:
- Pass
--tooland--tool-args. Probing calls a tool for real, once per request. Without real arguments, placeholders are synthesized from the schema, and if the server rejects them the scan refuses and exits 2 rather than scoring the rejection. - Probing a write tool writes. Auto-selection only picks a tool it can establish is
read-only; a tool that changes state needs
--allow-mutating. Point that at something disposable. - Credentials:
--headerfor http/sse,--env KEY=VALUEfor a stdio server — the MCP SDK does not pass your shell environment to the child process. Values are redacted in every report and export. - A rate-limited dependency reads as an unreliable one. The scan becomes part of the
load. Scale
--requeststo the quota. - The concurrency ramp is more than half the traffic. At the defaults it walks 1, 2, 4
and 5 concurrent and sends
--requestsat each level: 80 of the 140 calls a--requests 20scan made against a real server, counted from that server's own state.--requests 20 --probes latency,contract,fault,behaviordrops it, and costs nothing in the score — no policy threshold reads concurrency, so it is reported and never graded.
Transports: https://host/mcp (Streamable HTTP), stdio://./server.py, and
sse+https://host/sse (deprecated by the 2025-06-18 spec).
The detail behind each of these — the refusal messages, the read-only gate, credential
redaction, --scan-timeout — is in docs/SCANNING.md.
Validated on two SQLite MCP servers. --verify-tool was run against
npx mcp-sqlite@1.0.9 (create_record / read_records) and
npx mcp-server-sqlite-npx@0.8.0 (write_query / read_query), each writing an
{op_id} into a throwaway database. Both reported duplicate_mutations from the
database's own contents — one operation applied twice on each, two on one arm — and a
stdlib-only script that re-derives the ids and counts the rows agreed with every number.
This is what a plain insert does under at-least-once retry: the reply was dropped after
the row was written, the caller retried, and a second row appeared. Neither server is
doing anything wrong, and neither finding is a bug report against them — an insert with
no idempotency key behaves exactly this way, which is why it is the case worth being able
to measure.
Agents (experimental)
New in 1.5.0, extended in 1.6.0, and not frozen. Phase D is in progress: 1.6.0 is what
came back from pointing the scan at a real agent for the first time. --target agent scans
an agent rather than a server:
the agent is launched per task with an MCP config pointing at ratemyagent proxy, which
sits in front of the real MCP server, injects faults from a forced schedule and records
every call. With --verify-tool the scan reads the server's state before and after each
task, one task at a time, and joins what the agent claimed with what the record and
the state show:
| metric | reads | scored |
|---|---|---|
| duplicate mutations | effects above the task's expected_effects |
yes, absolute (cap 49) |
| retry amplification | calls under fault over the clean-path calls | yes |
| unsupported claims | agent said success, the record holds no successful reply | no |
| lost effects | the server replied success and applied nothing — the server's fault | no |
| lost acknowledgements | agent said failure, the work was applied | no, report only |
| backoff shape, retry-after honored | wall-clock gaps between attempts | no |
An agent scan gets a verdict only with --verify-tool, every task's state read, and at
least one task where a call went unanswered — otherwise nothing tested whether the agent
could apply a write twice. Short of that it prints NO VERDICT with the reason, and ci
exits 2. The server's state must persist outside its process (a file or a database): the
agent and the verify tool each start their own copy of a stdio server, and a scan whose
verify tool cannot see a clean task's write refuses before the faulted pass.
Validated against scripted agents only: three fixtures that never import this package
— careful (one idempotency key per operation, growing backoff, honours the hint),
blind (no key, no wait) and optimistic (blind, then claims success anyway) — against a
server twin whose own ledger records every call as applied or absorbed. Under one forced
schedule careful passes, blind is capped at 49 for a duplicate the ledger confirms, and
only optimistic makes unsupported claims. From a checkout:
ratemyagent scan --target agent \
--agent "python tests/fixtures/agents/careful_agent.py" \
--tasks tests/fixtures/agents/tasks-demo.json \
--upstream "stdio://python tests/fixtures/event_twin_mcp_server.py --mode append --state /tmp/rma-demo.jsonl" \
--verify-tool effects --verify-count entries \
--allow-mutating --fault-rate 0.7
Swap careful_agent.py for blind_agent.py or optimistic_agent.py and nothing else.
Validated on one real agent
claude-haiku-4-5 driven by Claude Code 2.1.275, launched per task through the MCP
config it already reads, against the event twin. Two findings, and both are about what
at-least-once delivery does at the tool boundary rather than about this agent.
It applied no client-side deadline to a dropped reply. The call was made, the upstream
applied it, the proxy dropped the reply — and the agent waited 234 seconds with no
retry, no return and no notifications/cancelled, until the scan's own task deadline
killed it. A separate probe held a reply for 90 seconds and then released it: the agent
waited the whole 90 and accepted the late answer, so this is the absence of a deadline
rather than a long one. The scan refuses to score that run, and the refusal is the point —
what is being measured is the agent's next decision, and there was none to observe. The two
MCP SDKs disagree on this by default (the TypeScript one bounds a request at 60s, the
Python one sets no timeout at all), so which behaviour a host gets is a property of the
host.
Under --lost-reply-close-after, it retried without an idempotency key. With the
session closed a few seconds after the reply was dropped, the same agent reconnected and
re-sent the write — and the retry carried no idempotency_key, though its first attempt
had invented one. The upstream had nothing to recognise the repeat by, so it applied the
write twice: duplicate mutations 1, score 49/100, against expected_effects: 1. The
twin's own ledger confirms two applications, and
examples/phase-d/verify_independent.py re-derives the count from
that ledger without importing this package.
On five replicates it kept its key in four and dropped it in one. The Phase D gate run put the same agent through five runs of one task, all five faulting the same call. It reconnected and retried every time; four of those retries carried an idempotency key derived from the task's own content, and one carried none. Zero duplicate mutations and zero unsupported claims, confirmed against the twin's own ledger from outside. One agent on one task is not a rate, and neither are five runs of it — the finding is what this agent did on these five runs, not what agents do.
That run is also what produced 1.6.2: it scored 100/100 PASS while four of its five runs applied nothing, because the scan's own clean pass had already spent the agent's key.
This is what a write retried after an unknown outcome does. The agent could not know whether its call had landed, and trying again is the reasonable move; an upstream with no way to recognise the repeat then applies it twice. Neither finding is a bug report against Claude Code, exactly as the SQLite results above are not bug reports against those servers — it is the case worth being able to measure, on the class of agent most people are actually shipping.
Four runs, one task, one model. claude-haiku-4-5 was chosen because the spike was
testing plumbing rather than reasoning. A stronger model may retry differently, keep its
key, or not retry at all, and nothing here is a rate: one agent measured is one agent
measured.
1.6.0 is what those findings demanded. --lost-reply-close-after ends the session a few
seconds after the reply is dropped, so a client with no deadline gets an event it cannot
ignore while still not learning whether its write applied — a different fault, counted
separately from response_lost everywhere. --agent-command, --claim-path and
--work-dir are the rest: the 1.5.1 fixed argv could not launch a hosted CLI at all,
because --tasks is not a flag Claude Code has.
What an agent must accept and print is in docs/SCANNING.md, and what this cannot tell you is in docs/LIMITATIONS.md.
How a scan works
Three phases, in order. Phase 2 needs phase 1 to compare against; phase 3 reads what phase 2 recorded.
Phase 1 — Baseline. Latency, cost, concurrency and contract probes measure the target as it is. These are the numbers everything else is compared against.
Phase 2 — Fault injection. A FaultProxy wraps the target and injects faults at a
configurable rate. Probes cannot tell they are wrapped, so the same probes run against a
sabotaged target and any difference is attributable to the faults.
Phase 3 — Behavior analysis. Reads the trajectory of every operation phase 2 disrupted: did it recover, how long did that take, how many calls did one operation cost. This is the part that is not a load test — it measures behaviour under failure, not failure counts.
Against something that retries — an agent, or a client wrapping a service — the trajectory is the target's. Against a bare server the retry loop belongs to the scanner, so what gets scored there is target survivability.
The contributor-facing walkthrough is in docs/ARCHITECTURE.md.
Scoring
Results are scored 0–100 against a YAML policy. Probes measure; the policy decides.
- Meeting a threshold scores 100 for that check — a threshold is a limit, not a target.
- Missing it decays linearly to 0 at twice the limit, so a near miss and a catastrophe do not score alike.
- A metric the scan could not produce is skipped, not zeroed. Missing evidence is not a failure.
- Passing requires both a score at or above
pass_scoreand no failed check. A failed check also caps the score at 89, or at 49 for a contract crash or a duplicate mutation, so one failure cannot be averaged away. A duplicate-mutation failure needs--verify-tool; without it the check is skipped rather than passed.
# my-policy.yaml
name: my-service
thresholds:
p95_latency_ms: 3000
error_rate_max: 0.02
recovery_rate_min: 0.95
retry_amplification_max: 1.5
duplicate_mutation_max: 0
pass_score: 80
ratemyagent policy # show the shipped defaults
ratemyagent scan --target mock --policy my-policy.yaml
Every threshold is optional, and an unknown key is an error rather than silently unscored. Full reference, including the shipped default explained threshold by threshold and how the caps work: docs/POLICY.md.
CI integration
ratemyagent ci --target mcp --uri stdio://./server.py --policy production.yaml
echo $? # 0 pass, 1 fail, 2 the scan could not run
Exit code 2 matters: a broken scanner is not a failing target, and a gate that cannot tell
them apart is not worth having in a pipeline. Failed checks are printed individually, and
--scan-timeout bounds the whole run so a hung handshake fails cleanly instead of burning
the job's time limit.
ci is the gate; scan is not. scan prints FAIL and still exits 0 — it reports,
and a reporting command that exits non-zero breaks every pipeline that runs it for the
artifact. Only ci turns the verdict into an exit code, so a gate that greps scan's
output for FAIL is not a gate. Both exit 2 when the scan could not run at all, which
since 1.4.1 includes a run refused because the target still holds the ids this seed would
write, and a run whose --verify-tool was requested but did not measure.
# .github/workflows/reliability.yml
name: reliability
on: [push, pull_request]
jobs:
scan:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: astral-sh/setup-uv@v5
with:
python-version: "3.12"
- run: uv pip install --system '.[mcp]'
- name: Reliability gate
run: |
ratemyagent ci \
--target mcp --uri stdio://./server.py \
--policy production.yaml \
--requests 120 --concurrency 16 --fault-rate 0.25 \
--json-out scan.json
- uses: actions/upload-artifact@v4
if: always()
with:
name: reliability-scan
path: scan.json
Use enough requests that the numbers mean something. recovery_rate from the default 20
requests is measured over roughly 4 disrupted operations, which is an anecdote rather than
a rate.
AGENTS.md and the report
ratemyagent scan --target mcp --uri stdio://./server.py --output all
# then, in Claude Code, Codex, Cursor or whatever you use:
# "Read AGENTS.md and fix what it found."
Both markdown outputs are written to be handed straight to a coding agent.
AGENTS.md is the fix guide — findings with root causes and copy-pasteable patches.
REPORT.md is the evidence behind them — every metric, every probe, and how the scan was
run, organized by phase. Hand over the first to get work done, the second when you want
the model to check the reasoning rather than trust it. They are about 2,300 and 1,700
tokens, so both fit in any context window.
Each finding states what was observed, why it matters in production, the root cause — weighted toward what AI-generated servers actually get wrong — and a fix naming the tool that failed:
FINDING: 9 schema-forbidden inputs accepted
Your tool declares required fields and types in its JSON Schema but does not enforce them at runtime. This is common in AI-generated MCP servers where the schema is correct but the handler trusts its input. Every field marked "required" needs an explicit check before the handler touches the data, because the calling agent WILL send malformed arguments — that is normal traffic, not an attack.
Suggested fix for tool "search_database":
if "query" not in args or not isinstance(args["query"], str): return {"error": "query is required and must be a string"}
Re-scanning into the same file reports what changed since the last scan. Real output is in
examples/: a scan of the official mcp-server-git
(AGENTS.md, report)
and a deliberately broken mock that triggers every
finding at once.
Known limitations
Each of these affects scores you can produce today. The full account, with the measurements behind each one, is in docs/LIMITATIONS.md — read it before relying on a number.
- Retry behaviour is not scored against a bare MCP server. A server does not retry;
the scanner does, so retry amplification describes RateMyAgent. It is reported, marked
n/a, and is scored only against--target agent, where the loop is the agent's. - Agent scans are experimental and narrow. Tasks run one at a time, and the Retry-After
hint reaches an agent in the tool error body, a convention a real client may not read. One
real agent has been scanned; it has no read timeout, so a dropped reply hangs it until the
task deadline unless
--lost-reply-close-afterends the session for it. - The scan's own clean pass writes to the store your repeats run against. One clean pass,
N chaos runs, one persistent store. An agent whose idempotency key derives from the task's
content sends the same key every run, and a server that absorbs a repeated key absorbs it
across runs — so later runs can apply nothing for a reason that is not about the agent. The
scan says so in a caveat and does not repair it; isolating state per run is your fixture's
job (how).
Since 1.6.2 a run in which every mutating task applied nothing gets
NO VERDICTrather than PASS, andciexits 2 — a coverage rule, not a penalty: no score moves. - Duplicate mutations need
--verify-tool. Left to itself the scan counts calls it re-sent after dropping a reply and reports that as its own; it cannot see whether the target applied them twice. Pass a read-only tool that reports the target's state, with{op_id}in--tool-args, and the metric is measured per operation (how). Without it the check is skipped, not passed — and since 1.4.1 a scan whose oracle was requested but did not measure never prints PASS, andciexits 2. - Synthesized arguments are shallow. A scan refuses when the server rejects them, but a tool that accepts a placeholder is profiled on a trivial call.
- Network-backed targets vary run to run. Quote a range from repeated runs, with the count.
- The scan can cause the failure it reports. Against a rate limiter, retries add load.
Since 1.0.1 the scan backs off and honours
Retry-After, but it does not detect a quota. - A latency figure describes the path the call took. A cache hit is a real cost, not a round trip to the dependency the tool's name implies.
- Faults are transient. Each attempt is faulted independently; sustained outages are not modelled.
API stability
1.0 means the frozen surface will not break without a major version. It does not mean the findings are finished — the section above says plainly what this tool still cannot measure.
Frozen: scan(), the target adapters, ProbeConfig, Policy, the result
shapes (ScanResult, ProbeResult, CheckResult, Caveat), ErrorKind and
FaultKind members, the CLI flags, the exit codes, and the eleven metric names
a policy threshold reads.
Not frozen: the rest of ProbeResult.metrics, Response.meta, and
ProbeConfig.extra keys with no CLI flag behind them. The whole agent path
— AgentTarget, --target agent and its flags, ratemyagent proxy, the record format
and the agent metrics — is experimental and outside the freeze, and 1.6.0 changed it.
FaultKind.RESPONSE_LOST_THEN_CLOSED is the exception: FaultKind members are frozen,
adding one is a minor release, and that is why this is 1.6.0. Each is a reporting
channel rather than a contract, and anything a consumer comes to depend on gets
promoted to a named field by a written procedure rather than by habit.
docs/API-STABILITY.md is the full statement,
including the promotion rules and why each unfrozen thing is unfrozen. It ships
in the sdist. Wheels carry no docs directory, so from a wheel this section and
the file at the matching git tag are the reference.
Roadmap
-
Next —
ratemyagent chaosfor targeted single-fault scenarios;--contract-toolsto raise contract coverage above the default three (with a hazard noted in docs/SCANNING.md); a dry-run mode, which needs--verify-toolas its evidence that nothing was applied -
Agents — Phase C is done in 1.5.0:
AgentTarget, the proxy, per-task effect counting, and a gate passed against scripted agents. Phase D is in progress. 1.6.0 ships what the first real-agent spike demanded: a launch contract a hosted CLI can actually satisfy (--agent-command,--claim-path,--work-dir) andRESPONSE_LOST_THEN_CLOSED, without which an agent that sets no read timeout cannot be scored at all. 1.6.1 adds what repeats and a model's own choices demand of the reporting: the realized fault placement beside the intended one, a measurement of the agent's client-side read timeout (--hold-reply), and the withholding of three metrics that are properties of a retry loop rather than of a model.The Phase D gate run has been attempted and was not met. Five replicates of one task against
claude-haiku-4-5, driven by Claude Code through the published 1.6.1 wheel, with the session closed five seconds after each dropped reply. All five runs faulted the same call, so they are replicates rather than five different experiments. The gate needs a duplicate mutation or an unsupported claim in at least 2 of 5, independently confirmed; there were zero of each in five of five, so the gate is not met.What happened instead is the result, and it is worth stating plainly. The agent invented an idempotency key derived from the task's own id and payload, noticed the closed session, reconnected and retried in every run — and on five replicates it kept that key in four and dropped it in one. A retry that keeps its key is the behaviour that makes a repeat absorbable; the one that dropped it is the shape that applied a write twice in the 1.6.0 spike. One agent on one task is not a rate, and five runs of it are not a rate either; nothing here says how any other agent behaves, or how this one behaves elsewhere.
The run found two defects in the tool, and 1.6.2 is them. It scored 100/100, PASS while four of its five runs applied nothing at all — because the scan's own clean pass had already spent the agent's idempotency key, so every later run's writes were absorbed before they could land. A
duplicate_mutationsof 0 over a window where nothing applied is arithmetic over an empty set. 1.6.2 declines the verdict on such a run and names the carryover in a caveat; see the release notes. A re-run against isolated per-run state is what the gate needs next, and it is a run and not a build. -
v2 — sustained outage windows; historical trending across scans
Deliberately out of scope: web dashboards, continuous monitoring, framework-specific adapters, security scanning, and anything requiring a database.
Contributing
git clone https://github.com/SMWundefined/RateMyAgent.git
cd RateMyAgent
uv venv --python 3.12
uv pip install -e '.[dev]' # editable, with pytest and ruff
uv run pytest -q # prints the count; no network or API keys
uv run ruff check .
Start with docs/ARCHITECTURE.md — it covers the Target
interface, the FaultProxy, the trajectory model, and the policy engine, including the
parts that are load-bearing and the reasoning behind them.
House rules, in short:
- Every probe needs tests that run without API keys, a network, or an MCP server. Use the
mock targets in
tests/conftest.py. - Probes measure, the policy judges. A probe that emits a verdict is a bug.
- The
FaultProxyis the only place faults are injected. - No interactive prompts. This is an SRE tool; it has to stay pipeable.
- Say what you measured, not what you would like to be true. Findings call out thin evidence rather than letting it pass quietly.
License
Apache License 2.0 — see LICENSE and NOTICE.
Apache rather than MIT because it carries an express patent grant from contributors, and section 5 states that contributions are offered under the same terms unless you say otherwise. MIT is silent on both. Equally permissive; less for a legal review to work out.
Release files for ratemyagent 1.6.2
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| ratemyagent-1.6.2.tar.gz | 556.6 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| ratemyagent-1.6.2-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 823.4 kB
Release files / ratemyagent-1.6.2.tar.gz
| Download URL | ratemyagent-1.6.2.tar.gz |
|---|---|
| Size | 556.6 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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BLAKE2b-256 checksum How to use checksums |
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| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
No |
| Uploaded via |
uv/0.12.9 {"installer":{"name":"uv","version":"0.12.9","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}
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Release files / ratemyagent-1.6.2-py3-none-any.whl
| Download URL | ratemyagent-1.6.2-py3-none-any.whl |
|---|---|
| Size | 266.8 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
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|
BLAKE2b-256 checksum How to use checksums |
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|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
No |
| Uploaded via |
uv/0.12.9 {"installer":{"name":"uv","version":"0.12.9","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}
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