@decispher/mcp-server

The Decispher MCP server. It serves your team's engineering decisions, constraints and conventions to AI coding agents over stdio, so an agent knows why the codebase is the way it is before it changes anything.

Needs a Decispher account and an MCP API key from your dashboard.

Install

npx @decispher/mcp-server

Configure

Name your key once with the CLI, then point the config at the name:

npx decispher@latest link

Claude Code, Cursor, Windsurf and any other MCP client take the same shape.

{
  "mcpServers": {
    "decispher": {
      "command": "npx",
      "args": ["-y", "@decispher/mcp-server"],
      "env": {
        "DECISPHER_LINK": "acme"
      }
    }
  }
}

A link name is public and meant to be committed. The credentials it points at stay in ~/.decispher/links.json on your machine, so this file holds no secret and a teammate who clones the repo runs decispher link once to answer to the same name. acme/payments names a project-scoped key under the same company. On a machine holding no credentials that command is a browser sign-in, so nobody has to be sent a key for it to work.

Attaching memory sets

"env": {
  "DECISPHER_LINK": "acme/payments",
  "DECISPHER_SET": "design-system,incidents"
}

The link stores the sets you hold; the config picks which ride along. At most five, and past two or three they compete for one budget and crowd out what relevance retrieval would have found.

A key in the config, without the CLI

Still supported, and not deprecated. Three situations need it: the Decispher Worker injects credentials per run into a sandbox with no home directory, CI and containers are rebuilt every run, and trying MCP before installing the CLI.

"env": {
  "DECISPHER_API_URL": "https://api.decispher.com",
  "DECISPHER_API_KEY": "dsk_...",
  "DECISPHER_COMPANY_ID": "optional",
  "DECISPHER_IDENTITY_KEY": "dik_...",
  "DECISPHER_SET_KEY": "dset_..."
}

DECISPHER_COMPANY_ID is optional. Present, it is used and one round trip is skipped; absent, the server resolves it from the key on the first tool call. DECISPHER_API_URL still matters: without it the server talks to http://localhost:3000.

When both are set

They compose field by field, with each environment variable overriding just that one field of the link. So a link plus an explicit API key means that company's identity and sets with the narrower key substituted in. The one thing that cannot compose is two companies: an identity key is scoped to the company its API key belongs to, so a mismatch would resolve to nothing and personal memory would go dark. The server refuses to start on that combination and names both companies rather than running with memory silently off.

A DECISPHER_LINK naming a link this machine does not hold is an error, never a fallback. Quietly using an unrelated credential is the confusion links exist to end.

The server publishes its own tool list from your account's /capabilities, so a tool added on the server side appears in your client on its next start with no upgrade here.

What it exposes

Before you write code

• check_intent tells you whether a planned change conflicts with a team constraint, answering BLOCKED, WARN or CLEAR.
• get_constraints and check_conventions list the rules in force.
• get_context_for_file returns the decisions attached to a file, ranked by a symbol graph rather than by text similarity alone.

While you work

• search_decisions, get_decision, ask_knowledge_base, get_context_for_topic and get_related_context read the knowledge graph.
• capture_decision writes back what you learned.

Across sessions

• copy_chat compresses the current conversation into a portable snapshot and returns a key that works on any machine and in any Decispher-connected tool.
• paste_chat restores one. Sections that do not fit the response budget are named and held back behind a free continuation cursor; section fetches one in full, and excerpt reaches the per-stretch notes of a long conversation.
• list_clips finds a snapshot whose key you lost.

Branch memory

• store_read, store_write, store_list and store_link are the working memory your agents hand to each other across a branch.

Every tool is scoped to the key that called it: a project-scoped key never sees another project's record.

Costs

Reads and writes are priced in Decispher credits per your company's effort mode; /capabilities reports the current cost of every tool. paste_chat, list_clips and the branch-store tools are free.

Links

• decispher.com
• MCP server docs

Licensed under the terms in LICENSE.