Every question you can ask the graph.
One recording, queried from your coding agent (MCP), your editor (LSP), or the command line. The
local queries run on your recorded files. The Pro ones run on the hosted
graph, where every production deploy's runs pool into one. And cypher answers the
ones we didn't ship a tool for.
Test intelligence · local, free
verify_mock
Catch a lying mock. A stub that passes green but returns something the real collaborator never would. Mutation testing can't see it. The recording can.
See more →split_interface
Split a fat interface. A class whose callers each use a different slice of it. It names the role interfaces to split it into, measured from who actually calls what.
See more →dead_api
Find dead public API. Public methods no caller reached in any recorded run, including the ones whose only caller is their own spec. Greyed out in your editor.
See more →unit_test_candidates
Test what matters. Untested methods ranked by how many places call them, so the most-depended-on code gets a test first. Aim your mutation runs there too.
See more →how_to_reach
Reach any method. The collaborators and call path that get an object into the state a method needs, taken from a real run. Setup for tests that use real objects instead of doubles.
See more →observed_shape
The observed contract. The messages your code actually sends to a value, read from real runs. The interface a call depends on, whether or not anyone declared it.
See more →testing_pyramid
The boundaries your pyramid misses. Seams that are only ever crossed through a double, never for real, mapped onto your testing pyramid. Record production too and they're ranked by traffic.
See more →specs_that_reach
Run only the specs that matter. The spec examples whose recorded runs reach a method, so a change reruns those and nothing else. Keeps a red-green loop in seconds.
See more →how_far_it_reached
Is your unit test a unit test? For each spec example, how many classes its real call tree touched and how deep it went. A unit spec that reaches thirty classes is telling you something.
See more →Ask the call graph · local, free
what_calls
Who can call this method. Every caller of a method from real runs, with where and how often. The calls that actually happened, not grep. what_it_calls does the reverse.
See more →how_it_got_here
How execution got here. The real call chains that reach a method, in order, taken from recorded runs. The stack trace you'd have got if it had raised, on demand, for every route in.
See more →where_time_goes
Where the time goes. The most-travelled call chains, ranked by how often they run, so caching and optimisation land where the traffic actually is.
See more →what_a_change_touches
What a change touches. Every caller that relies on a method's observed shape, the argument classes it passes and the messages it sends to what comes back, so you know what a signature change reaches before you make it.
See more →what_it_receives
What a method receives. The observed shape of each argument at a call site. The messages the method actually sends to what it's passed, not only the class it was given.
See more →who_actually_answered
Who actually answered. At a duck-typed call site, the concrete classes that received the message at runtime, and how often. Go to implementation, from real runs.
See more →where_nil_comes_from
Where nil shows up. The methods that returned nil and the arguments that received it at runtime, logged as NilClass and tied to the errors that followed. The case a declared type quietly hides.
See more →whats_looping
N+1 and hot loops. The same call site hit many times in one run, read straight off the call trees. A query in a loop, or the same question asked over and over.
See more →Software design · local, free
feature_envy
Move a method to where it belongs. A method that sends most of its calls to another object and barely touches its own. It names the object to move it onto, from real call counts.
See more →relocate_file
Which file should move where. Two files that lean on each other constantly but sit directories apart. The graph names the folder they belong in, weighed by real call traffic and the distance between them.
See more →break_cycle
Cut a dependency cycle. Files or namespaces caught in a runtime dependency cycle, flagged with the single lowest-traffic edge to sever to break the loop.
See more →stabilize_dep
Point dependencies at stability. A stable module, with many callers and few dependencies, reaching into a less stable one. Measured from real call traffic, so you can depend toward stability or put an abstraction between them.
See more →split_package
Split a package used in parts. Consumers that pull in a whole namespace but touch disjoint pieces of it. Split it so nobody takes a dependency on code they never call.
See more →check_diff
Catch it in review. Point it at a branch or PR and it flags only what the change introduced, before it lands: a drifted mock, a fresh dependency cycle, new feature envy.
See more →The design playbook, with the worked report →
Everything above is free. Not a trial, not a free tier with the good bits held back: every local tool, free with an account, running on your laptop. Your recordings stay there unless you opt in to sending them. Sign up free →
Your whole app, from production, on the hosted graph Pro
find_implementers
A real type for any interface. Search your whole app for a class that satisfies a required message set. Swap it in, or generate a verified fake from its contract.
See more →prod_dead_api
Safe to delete, proven in production. Public methods no production run ever calls, pooled across every deploy of your app. Genuinely dead, proven by real traffic rather than guessed.
See more →coupling_map
Coupling from real load. Module and namespace coupling drawn from real production calls. Which parts of your app actually talk, and how much.
See more →cypher
Ask anything. Arbitrary Cypher over the shared graph, for the question we didn't ship a tool for.
See more →