Letta · Schema

BlockSchema

Block with human-readable ID for agent file

Artificial IntelligenceAgentsStateful AgentsMemoryMemGPTContinual LearningMCPMulti-AgentRAGOpen-Source

Properties

Name Type Description
value string Value of the block.
limit integer Character limit of the block.
project_id object The associated project id.
template_name object Name of the block if it is a template.
is_template boolean
template_id object The id of the template.
base_template_id object The base template id of the block.
deployment_id object The id of the deployment.
entity_id object The id of the entity within the template.
preserve_on_migration object Preserve the block on template migration.
label string Label of the block.
read_only boolean Whether the agent has read-only access to the block.
description object Description of the block.
metadata object Metadata of the block.
hidden object If set to True, the block will be hidden.
tags object The tags to associate with the block.
id string Human-readable identifier for this block in the file
View JSON Schema on GitHub

JSON Schema

letta-blockschema-schema.json Raw ↑
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/BlockSchema",
  "title": "BlockSchema",
  "properties": {
    "value": {
      "type": "string",
      "title": "Value",
      "description": "Value of the block."
    },
    "limit": {
      "type": "integer",
      "title": "Limit",
      "description": "Character limit of the block.",
      "default": 100000
    },
    "project_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Project Id",
      "description": "The associated project id."
    },
    "template_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Template Name",
      "description": "Name of the block if it is a template."
    },
    "is_template": {
      "type": "boolean",
      "title": "Is Template",
      "default": false
    },
    "template_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Template Id",
      "description": "The id of the template."
    },
    "base_template_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Base Template Id",
      "description": "The base template id of the block."
    },
    "deployment_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Deployment Id",
      "description": "The id of the deployment."
    },
    "entity_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Entity Id",
      "description": "The id of the entity within the template."
    },
    "preserve_on_migration": {
      "anyOf": [
        {
          "type": "boolean"
        },
        {
          "type": "null"
        }
      ],
      "title": "Preserve On Migration",
      "description": "Preserve the block on template migration.",
      "default": false
    },
    "label": {
      "type": "string",
      "title": "Label",
      "description": "Label of the block."
    },
    "read_only": {
      "type": "boolean",
      "title": "Read Only",
      "description": "Whether the agent has read-only access to the block.",
      "default": false
    },
    "description": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Description",
      "description": "Description of the block."
    },
    "metadata": {
      "anyOf": [
        {
          "additionalProperties": true,
          "type": "object"
        },
        {
          "type": "null"
        }
      ],
      "title": "Metadata",
      "description": "Metadata of the block.",
      "default": {}
    },
    "hidden": {
      "anyOf": [
        {
          "type": "boolean"
        },
        {
          "type": "null"
        }
      ],
      "title": "Hidden",
      "description": "If set to True, the block will be hidden."
    },
    "tags": {
      "anyOf": [
        {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "title": "Tags",
      "description": "The tags to associate with the block."
    },
    "id": {
      "type": "string",
      "title": "Id",
      "description": "Human-readable identifier for this block in the file"
    }
  },
  "type": "object",
  "required": [
    "value",
    "label",
    "id"
  ],
  "description": "Block with human-readable ID for agent file"
}

Work with this as data

Every JSON Schema here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for schemas

4 MCP tools reach this
  • find_json_schemasBrowse and filter every JSON Schema in the catalog.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools

Call it yourself

curl for this page
This JSON Schema
curl "https://apis.io/api/v1/json-schemas/letta-blockschema"
All schemas
curl "https://apis.io/api/v1/json-schemas?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no email required.

A second provider on the same verified email joins the account you already have.