thoughtchain

thoughtchain is a standalone Rust crate for durable agent memory.

It stores semantically typed thoughts in an append-only, hash-chained memory log through a swappable storage adapter layer. The current default backend is JSONL, but the chain model is no longer tied to that format. Agents can:

• persist important insights, decisions, constraints, and checkpoints
• record retrospectives and lessons learned after hard failures or non-obvious fixes
• relate new thoughts to earlier thoughts with typed graph edges
• query memory by type, role, agent, tags, concepts, text, and importance
• reconstruct context for agent resumption
• export a Markdown memory view that can back MEMORY.md, MCP, REST, or CLI flows

The crate is intentionally independent from cloudllm so it can be embedded in other agent systems without creating circular dependencies.

What Is In This Folder

thoughtchain/ contains:

• the standalone thoughtchain library crate
• server support for HTTP MCP and REST, enabled by default
• the thoughtchaind daemon binary
• dedicated tests under thoughtchain/tests

Build

From inside thoughtchain/:

cargo build

Build only the library without the default daemon/server stack:

cargo build --no-default-features

Test

Run the crate tests:

cargo test

Run tests without the default server feature:

cargo test --no-default-features

Run rustdoc tests:

cargo test --doc

Generate Docs

Build local Rust documentation:

cargo doc --no-deps

Generate docs for the library-only build:

cargo doc --no-deps --no-default-features

Run The Daemon

The standalone daemon binary is thoughtchaind.

Run it:

cargo run --bin thoughtchaind

Install it from the crate directory:

cargo install --path . --locked

When it starts, it serves both:

• an MCP server
• a REST server

It prints the active chain directory, default chain key, and bound MCP/REST addresses on startup.

Daemon Configuration

thoughtchaind is configured with environment variables:

• THOUGHTCHAIN_DIR Directory where ThoughtChain storage adapters store chain files.
• THOUGHTCHAIN_DEFAULT_KEY Default chain_key used when requests omit one. Default: borganism-brain
• THOUGHTCHAIN_STORAGE_ADAPTER Storage backend for newly opened chains. Supported values: jsonl, binary. Default: jsonl
• THOUGHTCHAIN_BIND_HOST Bind host for both HTTP servers. Default: 127.0.0.1
• THOUGHTCHAIN_MCP_PORT MCP server port. Default: 9471
• THOUGHTCHAIN_REST_PORT REST server port. Default: 9472

Example:

THOUGHTCHAIN_DIR=/tmp/thoughtchain \
THOUGHTCHAIN_DEFAULT_KEY=borganism-brain \
THOUGHTCHAIN_STORAGE_ADAPTER=jsonl \
THOUGHTCHAIN_BIND_HOST=127.0.0.1 \
THOUGHTCHAIN_MCP_PORT=9471 \
THOUGHTCHAIN_REST_PORT=9472 \
cargo run --bin thoughtchaind

Server Surfaces

MCP endpoints:

• GET /health
• POST /
• POST /tools/list
• POST /tools/execute

REST endpoints:

• GET /health
• GET /v1/chains
• POST /v1/bootstrap
• POST /v1/agents
• POST /v1/thoughts
• POST /v1/retrospectives
• POST /v1/search
• POST /v1/recent-context
• POST /v1/memory-markdown
• POST /v1/head

Using With MCP Clients

thoughtchaind exposes both:

• a standard streamable HTTP MCP endpoint at POST /
• the legacy CloudLLM-compatible MCP endpoints at POST /tools/list and POST /tools/execute

That means you can:

• use native MCP clients such as Codex and Claude Code against http://127.0.0.1:9471
• keep using direct HTTP calls or cloudllm's MCP compatibility layer when needed

Codex

Codex CLI expects a streamable HTTP MCP server when you use --url:

codex mcp add thoughtchain --url http://127.0.0.1:9471

Useful follow-up commands:

codex mcp list
codex mcp get thoughtchain

This connects Codex to the daemon's standard MCP root endpoint.

Qwen Code

Qwen Code uses the same HTTP MCP transport model:

qwen mcp add --transport http thoughtchain http://127.0.0.1:9471

Useful follow-up commands:

qwen mcp list

For user-scoped configuration:

qwen mcp add --scope user --transport http thoughtchain http://127.0.0.1:9471

Claude Code

Claude Code supports MCP servers through its claude mcp commands and project/user MCP config. For a remote HTTP MCP server, the configuration shape is transport-based:

claude mcp add --transport http thoughtchain http://127.0.0.1:9471

Useful follow-up commands:

claude mcp list
claude mcp get thoughtchain

Claude Code also supports JSON config files such as .mcp.json. A ThoughtChain HTTP MCP config looks like this:

{
  "mcpServers": {
    "thoughtchain": {
      "type": "http",
      "url": "http://127.0.0.1:9471"
    }
  }
}

Important:

• /mcp inside Claude Code is mainly for managing or authenticating MCP servers that are already configured
• the server itself must already be running at the configured URL

GitHub Copilot CLI

GitHub Copilot CLI can also connect to thoughtchaind as a remote HTTP MCP server.

From interactive mode:

1. Run /mcp add
2. Set Server Name to thoughtchain
3. Set Server Type to HTTP
4. Set URL to http://127.0.0.1:9471
5. Leave headers empty unless you add auth later
6. Save the config

You can also configure it manually in ~/.copilot/mcp-config.json:

{
  "mcpServers": {
    "thoughtchain": {
      "type": "http",
      "url": "http://127.0.0.1:9471",
      "headers": {},
      "tools": ["*"]
    }
  }
}

Retrospective Memory

ThoughtChain supports a dedicated retrospective workflow for lessons learned.

• Use thoughtchain_append for ordinary durable facts, constraints, decisions, plans, and summaries.
• Use thoughtchain_append_retrospective after a repeated failure, a long snag, or a non-obvious fix when future agents should avoid repeating the same struggle.

The retrospective helper:

• defaults thought_type to LessonLearned
• always stores the thought with role = Retrospective
• still supports tags, concepts, confidence, importance, and refs to earlier thoughts such as the original mistake or correction

Shared-Chain Multi-Agent Use

Multiple agents can write to the same chain_key.

Each stored thought carries:

• agent_id
• agent_name
• optional agent_owner

That allows a shared chain to represent memory from:

• multiple agents in one workflow
• multiple named roles in one orchestration system
• multiple tenants or owners writing to the same chain namespace

Queries can filter by:

• agent_id
• agent_name
• agent_owner

Related Docs

At the repository root:

• THOUGHTCHAIN_MCP.md
• THOUGHTCHAIN_REST.md
• thoughtchain/WHITEPAPER.md
• thoughtchain/changelog.txt