Every breaking change leaves fingerprints

Open a case

Start a run: paste a link, the 3 AI subagents take it from there

Paste a GitHub pull request or repo link and press Enter to launch all 3 autonomous subagents

Cold cases (example links):
SyncSnitch Multi-Agent Orchestrator The case in progress · live run
STARTING
Consumer: … RUN: w-20260928-033249-fa0f
Target: …
Subagent 1 · S3QUEUED

Schema Diff & AST Tracer

The Tracer · confirms real impact

Zero-token diff on REST, gRPC & DB; traces consumer AST reachability.

Breaking Changes
–
Surfaces
–
AST Candidate Hits
–
Public APIs
–

    agent syncsnitch-tracer

    Subagent 2 · S4QUEUED

    Downstream Code Transformer

    The Transformer · writes the adapter

    Synthesizes backward-compatible tolerant reader adapters for the consumer.

    Pattern
    Tolerant Reader Adapter
    Branch
    –
    Modified Files
    –
    Diffstat
    –
    Compatibility
    –

    agent syncsnitch-transformer

    Subagent 3 · S5–S6QUEUED

    Contract Verifier

    The Verifier · forensics lab

    Deterministic judge running the V1–V6 suite in a mock container harness.

    • V1 Consumer unit tests WAITING
    • V2 Fixtures schema match WAITING
    • V3 Dual-run vs Upstream v1 WAITING
    • V4 Dual-run vs Upstream v2 WAITING
    • V5 Prism contract examples WAITING
    • V6 Diff scope guardrails WAITING

    Final Verdict–

    agent syncsnitch-verifier

    SyncSnitch Live Agent Log StreamThe wiretap · every agent step as it happens STREAMING

      How a case gets solved

      The S1–S9 workflow pipeline · nine steps when an upstream pull request changes a contract

      An upstream team changed a contract. SyncSnitch found every downstream break, generated a backward-compatible fix, proved it in containers and opened a draft PR after a human approved.

      S1
      Dust for prints
      Detect

      Contract drift in OpenAPI, protobuf, Alembic

      Deterministic
      S2
      Follow the trail
      Trace

      Static trace to consumer file:line

      Deterministic
      S3
      The Tracer
      Tracer subagent

      Confirms the real impact

      AI subagent
      S4
      The Transformer
      Transformer subagent

      Writes the tolerant-reader adapter

      AI subagent
      S5
      The lab
      Verify

      V1–V6 checks in Docker containers

      Docker lab
      S6
      The Verifier
      Verifier subagent

      Reads failures, loops back once

      AI subagent
      S7
      The warrant
      Human approval gate

      A person approves or rejects

      Human
      S8
      File the case
      Draft PR

      Opens the companion draft PR

      Deterministic
      S9
      Close the file
      Run artifact

      Run record + replay page

      Deterministic

      The ruleHow SyncSnitch decides

      AI investigates and writes the fix. Code decides pass or fail. A person signs off.

      S1, S2, S8 and S9 use zero AI tokens. It only ever edits the downstream repo.

      Before you open a case

      What a repo needs

      Requirements for the full S1–S9 run · one GitHub repo with both services

      1 · The upstream service Owns the contract

      • REST: contracts/openapi.yaml in the service folder (or the repo root).
      • gRPC: a .proto file directly in contracts/.
      • Database: Alembic migrations in migrations/versions/*.py (new files between base and head).
      • A change to compare: a commit that edits those contracts. Paste a /pull/<n> or /compare/<base>...<head> link, or SyncSnitch picks the latest contract commit.

      2 · The consumer service Gets the fix

      • Another folder in the same repo with a pyproject.toml (a Python project).
      • Tests that run with uv run pytest -q: the Transformer and check V1 use exactly this.
      • Real usage of the changed fields in .py, .sql, .proto files or JSON fixtures under tests/. No usage means no breaking change for it, and the agents have nothing to fix.

      3 · Optional Stronger proof, private repos

      • A Dockerfile in both services and Docker on the machine running the site: V3–V5 run in containers. Without them they are reported as skipped, never as passed.
      • Private repos: the server needs GITHUB_TOKEN; opening the draft PR needs gh logged in with push access.

      Not supported yet: consumers in other languages than Python, and contracts in other paths. The cold cases on the home page (kshiti26-11/demo: orders-service → billing-service) meet every requirement.