Graph Indexer for OpenCode

Graph Indexer for OpenCode is a local MCP server that gives OpenCode exact references, call graphs and change impact from an index of your repository. Run npx graph-indexer init and it adds a graph-indexer entry to opencode.json; with --hooks it also installs an OpenCode plugin.

How do I add Graph Indexer to OpenCode?

From the repository root, with Node.js 22.5 or later:

npx graph-indexer init

init configures OpenCode when it finds opencode.json, opencode.jsonc or a .opencode folder. To force it, use npx graph-indexer init --agents opencode. OpenCode and Kilo Code share one init target, because Kilo Code reads the same configuration.

What does npx graph-indexer init change for OpenCode?

For OpenCode, init touches these files:

Use --dry-run to preview everything and --no-instructions to skip the AGENTS.md block. Re-running init updates the block in place between its graph-indexer:start and graph-indexer:end markers.

What does the manual OpenCode configuration look like?

OpenCode uses its own MCP format: a mcp object, a local type and the command as a single array. The entry init writes is:

{
  "mcp": {
    "graph-indexer": {
      "type": "local",
      "command": ["npx", "-y", "graph-indexer@3", "serve"],
      "enabled": true
    }
  }
}

With init --local, the command points at the bin/graph-indexer.mjs of your checkout instead of npx.

What does the OpenCode plugin do?

The Graph Indexer plugin for OpenCode appends short, factual context to the output of OpenCode’s read, grep, bash, edit and write tools. It asks the repository’s resident Graph Indexer process over a local socket, never over the network. It adds three things:

• Once the agent is crawling (several searches or reads since the last edit), a read also shows where the names in those lines are defined.
• After a search that missed a definition, the output says where the definition is.
• After an edit, it reports what the edit broke: syntax errors, calls that no longer fit a changed signature, removed names still in use.

The plugin fails open: if the process does not answer, it adds nothing. Install it with npx graph-indexer init --hooks. See how it works for the resident process.

What does OpenCode gain from Graph Indexer?

OpenCode’s agent gets eight read-only tools. find_references lists every real use of a symbol, bound through scopes, imports and receiver types. call_graph shows callers and callees, change_impact shows dependents and the tests to run, and check_changes verifies uncommitted edits without a build.

Against the TypeScript compiler on 400 nestjs symbols, find_references reached 99.7% precision and 96.2% recall, where grep reached 12.8% precision (benchmarks). Graph Indexer is not a type checker: generics, reflection, any and dependency-injection tokens are only partly visible. Graph Indexer itself makes no network calls and sends no telemetry; OpenCode still sends what it reads to its model provider. See the tools reference and the other agents.