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Letta (BYOK) — connector documentation

  • MCP endpoint: https://byok-letta.connectorbay.com/mcp
  • REST API: POST https://byok-letta.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-letta.connectorbay.com/openapi.json
  • Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
  • Authentication: your own Letta Letta API key, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
  • Health: https://byok-letta.connectorbay.com/health · Tool schemas: https://byok-letta.connectorbay.com/tools.json
  • Publisher: Unify Dynamics LLC · connectorbay.com/byok-letta · agent@connectorbay.com

What Letta (BYOK) is for

Letta (BYOK) lets an AI assistant read your own Letta data through the Letta API with a key you supply (Letta API key). Read-only: 12 tools (list_agents, get_agent, list_agent_messages, list_agent_memory_blocks, list_agent_tools, list_blocks, list_tools, list_runs, get_run, list_steps, list_models, list_folders). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to api.letta.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Letta. Letta and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

  • "Which Letta agents do I have?"
  • "Show the configuration of my Letta agent"
  • "What did my Letta agent say recently?"
  • "What is in my Letta agent's core memory?"
  • "Which tools does my Letta agent have?"
  • "Which shared memory blocks exist in my Letta project?"

What it does

  • list_agents: List the agents of the project with name, model, type, tags and last run time. Filter by name, tags or project.
  • get_agent: Get one agent: name, model, type, system prompt, tags, project and last run information. Secrets are not requested.
  • list_agent_messages: List the messages of an agent (user, assistant, reasoning, tool calls and tool returns) with type, time and content.
  • list_agent_memory_blocks: List the core memory blocks of an agent (such as persona and human) with label, value, character limit and read-only flag.
  • list_agent_tools: List the tools attached to an agent with name, description, type and approval setting. Source code is not requested.
  • list_blocks: List memory blocks of the project (shared or template blocks) with label, value, description and tags, filterable by label.
  • list_tools: List the tools of the project (built-in and custom) with name, description, type and tags. Source code is not requested.
  • list_runs: List agent runs (one run per request to an agent) with status, stop reason, timing and the agent id; filter by agent or status.
  • get_run: Get one agent run: status, stop reason, timing in nanoseconds and the agent and conversation it belongs to.
  • list_steps: List agent steps (single LLM calls) with model, token counts, status, stop reason and run id, filterable by agent, model or date.
  • list_models: List the language models the server offers, with handle, provider, context window and reasoning support.
  • list_folders: List folders (document collections for agents) with name, description, embedding configuration and times.

BYOK key

You bring your own Letta Letta API key (https://app.letta.com). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to api.letta.com over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

Live from the Letta API (api.letta.com) with a BYOK key; documentation: https://docs.letta.com/api/resources/agents. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Letta. Letta and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your Letta account.

Built for: Worldwide. Languages: English.