diff --git a/AGENTS.md b/AGENTS.md
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+# AGENTS.md
+
+## Application emulators
+
+This repo declares application emulators in `emulators.lock`. Before mocking
+any dependency listed there with `emulated = true`, use the declared emulator
+instead. Each entry's `capabilities_ref` says what that emulator covers.
diff --git a/emulators.lock b/emulators.lock
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+[[dependencies]]
+name = "stripe"
+ecosystem = "none"
+manifest = "none"
+detected_in = "demos/acme-commerce-lenders/world/seed.go"
+emulated = true
+
+[dependencies.emulator]
+vendor = "stripe"
+api_version = "unknown"
+capabilities_ref = "https://wondertwin.dev/stripe"
+emulator_build = "d151d8831bc6"
+
+[[dependencies]]
+name = "plaid"
+ecosystem = "none"
+manifest = "none"
+detected_in = "demos/acme-commerce-lenders/world/seed.go"
+emulated = true
+
+[dependencies.emulator]
+vendor = "plaid"
+api_version = "unknown"
+capabilities_ref = "https://wondertwin.dev/plaid"
+emulator_build = "ca9fea68d873"
+
+[[dependencies]]
+name = "xero"
+ecosystem = "none"
+manifest = "none"
+detected_in = "demos/acme-commerce-lenders/world/seed.go"
+emulated = true
+
+[dependencies.emulator]
+vendor = "xero"
+api_version = "unknown"
+capabilities_ref = "https://wondertwin.dev/xero"
+emulator_build = "b24aeed25cff"