Constant STEP_SCHEMA_JSON 

pub const STEP_SCHEMA_JSON: &str = "{\n  \"$schema\": \"https://json-schema.org/draft/2020-12/schema\",\n  \"$id\": \"https://schemas.fleetforge.dev/step.json\",\n  \"type\": \"object\",\n  \"required\": [\"id\", \"type\", \"inputs\"],\n  \"properties\": {\n    \"id\": { \"type\": \"string\", \"format\": \"uuid\" },\n    \"type\": { \"enum\": [\"llm\", \"tool\", \"map\", \"reduce\", \"branch\", \"replay\", \"agent\"] },\n    \"inputs\": {\n      \"type\": \"object\",\n      \"properties\": {\n        \"messages\": {\n          \"type\": \"array\",\n          \"items\": {\n            \"type\": \"object\",\n            \"required\": [\"role\", \"content\"],\n            \"properties\": {\n              \"role\": { \"enum\": [\"system\", \"user\", \"assistant\", \"tool\"] },\n              \"content\": { \"type\": \"string\" }\n            }\n          }\n        },\n        \"prompt_ref\": { \"type\": \"string\" },\n        \"prompt_params\": { \"type\": \"object\" },\n        \"tools\": {\n          \"type\": \"array\",\n          \"items\": { \"$ref\": \"#/$defs/toolSpec\" }\n        },\n        \"tool_choice\": {\n          \"anyOf\": [\n            { \"type\": \"string\", \"enum\": [\"auto\", \"none\"] },\n            { \"type\": \"string\", \"pattern\": \"^required:[a-zA-Z0-9_.-]+$\" }\n          ]\n        },\n        \"response_schema\": {\n          \"anyOf\": [\n            { \"type\": \"object\" },\n            { \"type\": \"string\" }\n          ]\n        },\n        \"response_strict\": { \"type\": \"boolean\", \"default\": true },\n        \"model\": { \"type\": \"string\" },\n        \"temperature\": { \"type\": \"number\", \"minimum\": 0, \"maximum\": 2 },\n        \"context_sources\": {\n          \"type\": \"array\",\n          \"items\": { \"$ref\": \"#/$defs/contextSource\" }\n        }\n      },\n      \"additionalProperties\": true\n    },\n    \"policy\": {\n      \"type\": \"object\",\n      \"properties\": {\n        \"guardrails\": {\n          \"type\": \"array\",\n          \"items\": { \"type\": \"string\" }\n        },\n        \"packs\": {\n          \"type\": \"array\",\n          \"items\": {\n            \"type\": \"object\",\n            \"required\": [\"name\"],\n            \"properties\": {\n              \"name\": { \"type\": \"string\" },\n              \"id\": { \"type\": \"string\" },\n              \"phase\": {\n                \"anyOf\": [\n                  { \"type\": \"string\", \"enum\": [\"pre\", \"mid\", \"post\"] },\n                  {\n                    \"type\": \"array\",\n                    \"items\": { \"type\": \"string\", \"enum\": [\"pre\", \"mid\", \"post\"] },\n                    \"minItems\": 1\n                  }\n                ]\n              },\n              \"hooks\": {\n                \"anyOf\": [\n                  { \"type\": \"string\", \"enum\": [\"pre\", \"mid\", \"post\"] },\n                  {\n                    \"type\": \"array\",\n                    \"items\": { \"type\": \"string\", \"enum\": [\"pre\", \"mid\", \"post\"] },\n                    \"minItems\": 1\n                  }\n                ]\n              },\n              \"options\": { \"type\": \"object\" }\n            },\n            \"additionalProperties\": false\n          }\n        },\n        \"egress_profile\": {\n          \"type\": \"string\",\n          \"enum\": [\"none\", \"allowlist\", \"tenant-default\"]\n        },\n        \"isolation\": {\n          \"type\": \"string\",\n          \"enum\": [\"docker\", \"firecracker\"]\n        }\n      },\n      \"additionalProperties\": true\n    },\n    \"execution\": {\n      \"type\": \"object\",\n      \"properties\": {\n        \"max_attempts\": {\n          \"type\": \"integer\",\n          \"minimum\": 1,\n          \"default\": 1\n        },\n        \"retry_backoff_ms\": {\n          \"type\": \"integer\",\n          \"minimum\": 0,\n          \"default\": 0\n        },\n        \"retry_backoff_factor\": {\n          \"type\": \"number\",\n          \"minimum\": 1,\n          \"default\": 1\n        },\n        \"deadline_ms\": {\n          \"type\": \"integer\",\n          \"minimum\": 1\n        },\n        \"checkpoint\": {\n          \"type\": \"boolean\",\n          \"default\": false\n        },\n        \"compensation\": {\n          \"type\": \"object\",\n          \"properties\": {\n            \"step\": { \"type\": \"string\", \"minLength\": 1 },\n            \"reason\": { \"type\": \"string\" }\n          },\n          \"required\": [\"step\"],\n          \"additionalProperties\": false\n        },\n        \"cost_hint\": {\n          \"type\": \"object\",\n          \"properties\": {\n            \"tokens\": { \"type\": \"integer\", \"minimum\": 0 },\n            \"usd\": { \"type\": \"number\", \"minimum\": 0 }\n          },\n          \"additionalProperties\": false\n        }\n      },\n      \"additionalProperties\": false\n    }\n  },\n  \"additionalProperties\": false,\n  \"$defs\": {\n    \"toolSpec\": {\n      \"type\": \"object\",\n      \"required\": [\"name\", \"schema\", \"description\"],\n      \"properties\": {\n        \"name\": { \"type\": \"string\" },\n        \"description\": { \"type\": \"string\" },\n        \"schema\": { \"type\": \"object\" }\n      }\n    },\n    \"contextSource\": {\n      \"type\": \"object\",\n      \"required\": [\"kind\"],\n      \"properties\": {\n        \"kind\": { \"enum\": [\"memory:kv\", \"memory:vector\", \"artifact\", \"input\"] },\n        \"namespace\": { \"type\": \"string\" },\n        \"key\": { \"type\": \"string\" },\n        \"top_k\": { \"type\": \"integer\" },\n        \"query\": { \"type\": \"string\" }\n      }\n    }\n  }\n}\n";

Embedded JSON schemas shared across FleetForge surfaces.