Lawang Onboard

Permission-aware AI onboarding. An onboarding copilot inside IBM Bob that explains a codebase to a new engineer, and only the parts they are allowed to see.

Built for the IBM Bob 2.0 Hackathon (lablab.ai, 25 to 27 September 2026) by team Lawang Onboard.

The problem

A new engineer, or a contractor hired for one module, needs weeks to learn why a codebase looks the way it does. The answers exist, spread across commit messages, architecture decision records and pull request reviews, but nobody reads those on day one. And access is all or nothing: either the newcomer sees everything, including whatever an AI assistant can read into its context, or they wait for someone to explain.

Related MCP server: Sippion

What it does

Open the repository in IBM Bob, switch to the Onboard mode, and ask:

• /tour: the map of what you can see, module by module.

• /trace webhook: how a webhook becomes a record, step by step.

• /why internal/ingress: the decisions and reviews behind a path.

• "What can I pick up first?"

Bob answers from the code and its history, and cites every item it used. Every piece of context carries a scope; the engineer's role maps to a set of scopes; the role comes from the token on the connection; and the Lawang Onboard MCP server filters before the model sees anything. A contractor's session cannot leak what it was never given, and every answer ends with what was withheld:

Withheld: path:cmd (68), path:internal/core (314), path:migrations (56), path:repo (86),
private:growth (18), private:security (6) | total hidden: 399

Results

Measured on 26 September with the contractor role, one fresh Bob task per question, by a team member who did not build the server. Full write-up: docs/benchmark.md.

How it works

IBM Bob (Onboard mode: rules, skills, slash commands)
        |  MCP over stdio or HTTPS, bearer token
        v
onboard server (Go)
  token -> role -> scopes -> one filter function -> tools -> audit log
        |
corpus/*.jsonl  (610 items: files, docs, ADRs, commits, PRs, reviews, issues, each with scopes)

• Scopes come from roles.yaml: path globs (first match wins), labels (a growth label makes an issue private) and kinds. An item needs every one of its scopes; an item with no scope is denied to everyone.

• Tools: whoami, map_system, search, get, trace_feature, why, setup_guide, starter_tasks, withheld. Each filters first and builds its answer only from visible items. A hidden id and a missing id get the same answer.

• Onboard mode can use only MCP tools and skills, not the file system, so Bob's only view of the code is the filtered one. Its rules make it call whoami first, cite item ids, treat corpus text as data, mark proposals as proposals and close with the Withheld line.

• Tokens are compared in constant time; an unknown, empty or ambiguous token is refused. The demo page's API uses the same tokens.

Design notes: docs/design.md.

Try it

• Live demo: https://lawang-onboard.samsulhadi.com (paste a role token to see that role's view).

• Connect a client: IBM Bob, Claude Code, Cursor and VS Code are set up below, over stdio through the published image or over HTTPS through the hosted server.

Connect your MCP client

server.json declares two ways in, and the nine tools and four prompts are the same through both:

0.1.2 is the tag to pull, and it is the first whose binary reports the tag as its serverInfo.version (0.1.1 reported 0.1.0) and the first that serves the prompts. Over stdio you are the operator: pick any secret, give it to one role, and set ONBOARD_TOKEN to the same value. That role decides what you see, and the image carries the Lawang demo corpus, so there is nothing else to set up. Over HTTPS the tokens are ours, so ask us for one.

Keep the secret out of any file you commit. The Bob, Claude Code and Cursor snippets below read it from your environment, so export it before you start the client; the VS Code snippets below do not read it, and VS Code prompts you for it once instead. The two values are deliberately the same: one names the role, the other says which role this client claims.

read -rs ONBOARD_TOKEN && export ONBOARD_TOKEN   # typed, so it stays out of your shell history
export ONBOARD_TOKEN_CONTRACTOR="$ONBOARD_TOKEN"

Then pick your client. Each snippet names the documentation it came from and the day that page was read; these clients change their configuration formats, so check the page if a snippet does not work.

IBM Bob

Copy .bob/mcp.example.json to .bob/mcp.json for a local server over stdio, or .bob/mcp.remote.example.json for the hosted one, put your token in, reload MCP servers, switch to the Onboard mode and type /tour. Both hold the token literally, in a file .gitignore keeps out of git. For the local one that is what the flow under "Run it locally" expects: scripts/use-role.py writes the token into that file's env object for you. The remote one you paste into headers yourself, because it has no env object and that script does not touch it. The block below keeps the token in your environment instead.

For the published image over stdio, with no Go toolchain:

{
  "mcpServers": {
    "lawang-onboard": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "ONBOARD_TOKEN", "-e", "ONBOARD_TOKEN_CONTRACTOR",
               "ghcr.io/gablooge/lawang-onboard:0.1.2", "-stdio"],
      "env": {
        "ONBOARD_TOKEN": "${env:ONBOARD_TOKEN}",
        "ONBOARD_TOKEN_CONTRACTOR": "${env:ONBOARD_TOKEN_CONTRACTOR}"
      }
    }
  }
}

So the file holds a variable name and never your secret. Three Bob details behind that, measured on 12 October 2026 (Bob IDE 2.2.1 and Bob Shell 2.0.5, which carry the same MCP client):

• Bob expands ${env:NAME} from its own environment. env and headers were tested; args goes through the same walk over the entry. A bare ${NAME} is not expanded and arrives as that literal text, which is worth knowing before you copy a ${VAR} out of an older note.

• The env object is doing real work: Bob gives a stdio server a fixed allow-list (HOME, LOGNAME, PATH, SHELL, TERM, USER) plus the entry's own env, and nothing else. So -e ONBOARD_TOKEN on its own passes nothing on and the image exits with onboard: ONBOARD_TOKEN is not set. Keep both halves.

• Export the variables before you start Bob. Setting them in another terminal afterwards does not reach a Bob that is already running.

Claude Code

Two commands, from the claude mcp add reference (read 12 October 2026). --env values and header values are expanded from your environment when the server starts, so the ${...} text is what gets written to the configuration, not your secret. Everything after -- is passed to the server untouched, which is what lets docker run keep its own flags.

Over stdio, through the image:

claude mcp add --env 'ONBOARD_TOKEN=${ONBOARD_TOKEN}' \
  --env 'ONBOARD_TOKEN_CONTRACTOR=${ONBOARD_TOKEN_CONTRACTOR}' --transport stdio lawang-onboard \
  -- docker run -i --rm -e ONBOARD_TOKEN -e ONBOARD_TOKEN_CONTRACTOR \
     ghcr.io/gablooge/lawang-onboard:0.1.2 -stdio

Over HTTPS, through the hosted server:

claude mcp add --transport http lawang-onboard https://lawang-onboard.samsulhadi.com/mcp \
  --header 'Authorization: Bearer ${ONBOARD_TOKEN}'

Both write to local scope, which is this project only; add --scope user for every project. The single quotes matter: they stop your shell expanding the token into the stored command. Checked at that default scope on CLI 2.1.293: the entry lands in ~/.claude.json under this project's path, the ${...} text is what is stored, and claude mcp list reports Connected with the variables exported and Failed to connect without them, naming them as missing.

One silent failure to know about on the HTTPS entry. Under "Credential variables that read as empty", that page says some credential-like names read as empty instead of expanding in a remote server's url and headers. It gives three categories with examples rather than a list, and says a name outside them expands as written. ONBOARD_TOKEN is outside them, and it did expand on CLI 2.1.293, measured against a local endpoint that logged the header it received. If yours reads as empty, the header goes out as a bare Bearer and this server answers 401. claude mcp list is the quick check; claude --debug-file /tmp/claude-debug.log and a search for "never expanded toward a remote server" is the one that names the variable.

Cursor

.cursor/mcp.json in the project, or ~/.cursor/mcp.json for every project, under mcpServers. Cursor resolves ${env:NAME} in command, args, env, url and headers. From Cursor's MCP documentation (read 12 October 2026).

Over stdio, through the image. That page's stdio field table marks type required with the value "stdio", while none of its stdio examples carry it, so this snippet follows the table:

{
  "mcpServers": {
    "lawang-onboard": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "ONBOARD_TOKEN", "-e", "ONBOARD_TOKEN_CONTRACTOR",
               "ghcr.io/gablooge/lawang-onboard:0.1.2", "-stdio"],
      "env": {
        "ONBOARD_TOKEN": "${env:ONBOARD_TOKEN}",
        "ONBOARD_TOKEN_CONTRACTOR": "${env:ONBOARD_TOKEN_CONTRACTOR}"
      }
    }
  }
}

Over HTTPS, through the hosted server:

{
  "mcpServers": {
    "lawang-onboard": {
      "url": "https://lawang-onboard.samsulhadi.com/mcp",
      "headers": { "Authorization": "Bearer ${env:ONBOARD_TOKEN}" }
    }
  }
}

A remote entry is a url and optional headers; the documentation names no transport field, and Cursor works out streamable HTTP for itself.

VS Code

.vscode/mcp.json in the workspace, or the same file in your user profile, under servers. Fields and variables from the MCP configuration reference (read 12 October 2026): type, command, args, env and envFile for stdio, type, url and headers for a remote server. That page documents ${input:id} and ${workspaceFolder}, and not ${env:NAME}, so the token comes from an inputs entry: VS Code asks for it once, on first use, and stores it for later. Nothing here reads your exported variables.

Over stdio, through the image:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "onboard-token",
      "description": "Lawang Onboard role token",
      "password": true
    }
  ],
  "servers": {
    "lawang-onboard": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "ONBOARD_TOKEN", "-e", "ONBOARD_TOKEN_CONTRACTOR",
               "ghcr.io/gablooge/lawang-onboard:0.1.2", "-stdio"],
      "env": {
        "ONBOARD_TOKEN": "${input:onboard-token}",
        "ONBOARD_TOKEN_CONTRACTOR": "${input:onboard-token}"
      }
    }
  }
}

Over HTTPS, through the hosted server. Keep the inputs array from the block above in the file: on its own this entry leaves ${input:onboard-token} unresolved and VS Code rejects the configuration.

{
  "servers": {
    "lawang-onboard": {
      "type": "http",
      "url": "https://lawang-onboard.samsulhadi.com/mcp",
      "headers": { "Authorization": "Bearer ${input:onboard-token}" }
    }
  }
}

The same page describes a portable .mcp.json at the workspace root that uses mcpServers instead of servers, which is the shape the Bob and Cursor blocks above already have. The code --add-mcp command is on a different page, MCP servers in VS Code (read 12 October 2026); its example passes one JSON argument with escaped double quotes and covers name, command and args only, so for an entry with env or headers use the file.

The server is also listed in the MCP Registry as io.github.gablooge/lawang-onboard.

The four prompts, in any client

The nine tools are the same in every client, and so is the guidance around them. The Onboard mode's four skills (tour, trace, why, first-week) are written once, in .bob/skills/, and the server serves that same text as MCP prompts, each one preceded by the mode's rules from .bob/rules-onboard/: call whoami first, answer only from tool results, cite every item id, end with the Withheld line. trace takes a term and why takes a path; both are required, one line of at most 512 bytes with something visible in it, and the value is appended after the text as data, never substituted into it. So a client that is not Bob runs the tour as a tour:

Checked on 28 October 2026 with Claude Code 2.1.311 from an empty directory, the 0.1.2 build over stdio as contractor: /mcp__lawang-onboard__tour began with Role: contractor, called the tools through the server, produced a tour with an item id on every claim, and ended with the same line as the Bob run it is measured against (task 36 in bob_sessions/LEDGER.md): Withheld: path:cmd (68), path:internal/core (314), path:migrations (56), path:repo (86), private:growth (18), private:security (6) | total hidden: 399. What stays Bob's: the Onboard mode itself, which is what takes the file system away from the model (the limit below), and the three slash commands in .bob/commands/, which only switch to that mode.

One limit is worth stating plainly, because it is not a setting we can fix. The filter holds only while this server is the model's only view of the code. Bob's Onboard mode is configured without file system access, so there the filtered corpus is all the model has. Claude Code, Cursor and VS Code read your working tree by default, and a model that can open a file does not need to ask us for it: it sees whatever is checked out, whatever roles.yaml says. Nothing we ship changes that, and no option on our side could. If the point is to see what a role sees, connect from a client or a mode with no file access, or from a machine that has no clone. Otherwise the withheld counts describe the corpus, which is still true, and not your disk.

Run it locally

Needs Go 1.25.

cp .env.example .env                 # set the three role tokens
cp .bob/mcp.example.json .bob/mcp.json
scripts/use-role.py contractor       # writes that role's token into .bob/mcp.json

Open the folder in IBM Bob, reload MCP servers, pick the Onboard mode and ask away. Bob starts the server over stdio.

For the web page and the HTTP endpoint:

set -a; . ./.env; set +a
go run ./cmd/onboard -addr :47312               # http://localhost:47312, MCP at /mcp
go run ./cmd/onboard -addr :47312 -demo-roles   # local demos only: role buttons without tokens
make test                                       # go test -race -count=1 ./...

Hosting (Docker and a Cloudflare Tunnel, make up): docs/deploy.md.

To skip the Go toolchain entirely, run the published image instead: the snippets under Connect your MCP client do that for each client.

Use it on your own repository

The demo answers about Lawang, but nothing in the server is specific to it. A corpus and a roles file are all it reads. The export needs Python 3 and git, the server needs Go 1.25 or Docker. Every command below runs in a clone of this repository, and everything you make goes under local/, which git ignores.

1. Export. Point it at a local clone of your repository:

   make corpus REPO=../myrepo GITHUB=me/myrepo OUT=local/corpus

   This writes files, docs and commits from the clone, and pull requests, reviews and issues from GitHub (public repositories need no token; set GITHUB_TOKEN for a private one or a large one). GITHUB= with nothing after it skips GitHub and makes no network call. For a repository owned by an organisation, run the script directly and add --owner <your login>.

   What the export removes, and what it does not. It replaces a fixed list of token shapes (GitHub, Slack, AWS key ids, Stripe, Google, GitLab, npm, JWTs, bearer values, PEM private keys), passwords inside URLs, and, in configuration files, a literal value on the same line as a key whose name ends in password, secret, token or api_key, unless the value reads as a variable name (DB_PASSWORD_VAR) or a reference (var.db_password). In commit messages and GitHub text it also replaces email addresses and IP addresses, and it writes every author but the owner and bots as <user>. It leaves out symlinks, lock files, minified files, node_modules, vendor, third_party, and configuration files with secret, credential or passw in the name. It does not remove: @mentions and names written in the text of a commit or a pull request, GitHub noreply addresses (which contain a login), a secret of a shape it does not know, one stored under a neutral key, or one assigned in source code (PASSWORD = "..." in a .py file). So it is a net and not a guarantee. The counts are printed and kept in local/corpus/manifest.json; read the corpus before you share it. The raw GitHub answers, not scrubbed at all, are cached beside the corpus in local/.corpus-raw/, which ignores itself in git and is never mounted or served.

2. Say who sees what.

   cp roles.example.yaml local/roles.yaml

   Edit the globs to match your tree. Every line is commented. As the template is written, a directory you forget to list is shown to the maintainer role only. That holds for as long as you keep the last rule's scope (unlisted:repo) out of the other roles; the header of the file says what changes if you do not.

3. Run. Each role needs a token, in the variable its token_env names. Without them the page loads and every call answers 401:

   cp .env.example .env    # then set ONBOARD_TOKEN_MAINTAINER, _EMPLOYEE and _CONTRACTOR

   With Go:

   set -a; . ./.env; set +a
   go run ./cmd/onboard -addr :47312 -corpus local/corpus -roles local/roles.yaml

   Or with the published image, mounting both over the demo's:

   docker run --rm -p 47312:47312 --env-file .env \
     -v "$PWD/local/corpus:/app/corpus:ro" -v "$PWD/local/roles.yaml:/app/roles.yaml:ro" \
     ghcr.io/gablooge/lawang-onboard:0.1.2

   The MCP endpoint is http://localhost:47312/mcp and the page is at /. For stdio, take your client's docker run entry from Connect your MCP client and add the two -v mounts to its arguments, with absolute paths (there is no shell there to expand $PWD); it has no -p.

What you get depends on what the repository has. The tour, search, get, trace_feature and why work on any export. setup_guide reads the README, the Makefile and .github/workflows/. starter_tasks needs GitHub issues and a label_areas entry.

How IBM Bob is used

IBM Bob is both the product's runtime and the tool that built it. The Onboard mode, its rules, four skills (tour, trace, first-week, why) and three slash commands are the user interface. Plan mode designed the server, Agent mode wrote all of its code and tests, Ask mode reviewed it for leaks, and the Onboard mode ran the benchmark. 36 Bob tasks, 46.6 of the team's 80 Bobcoins; every task has a screenshot in bob_sessions/ and a row in the ledgers (Samsul, Ryan). Details, and what was done outside Bob: docs/submission/bob-usage.md.

Data and privacy

See DATA_SOURCES.md and PRIVACY.md. The demo corpus is the team's own open-source repository, gablooge/lawang; no client, confidential, personal or social media data is used. The roles are synthetic.

Team

• Samsul Hadi (lead)

• Ryan Rizki

License

MIT