# PRD 0050: Move provider-specific agent logic into contrib

- **Status:** Active
- **Author:** claude
- **Created:** 2026-06-03
- **Issue:** #177

## Summary

The agent provider module (`bot_bottle/agent_provider.py`) hard-codes
the Claude- and Codex-specific provisioning rules — auth file shapes,
trust-dialog markers, egress routes, dummy-auth dance, env vars — in a
single `if template == "codex": ... if template == "claude": ...`
chain (lines 154–230 today). Other pieces of provider behavior live in
each backend's `provision/` directory (`provision_skills`,
`provision_prompt`, `provision_provider_auth`, `provision_supervise`),
duplicated once per backend, even though almost none of what they do
is actually backend-specific.

This PRD reshapes the agent provider into a proper plugin boundary.
The two existing providers (Claude, Codex) move out of `agent_provider`
into `bot_bottle/contrib/claude/` and `bot_bottle/contrib/codex/` —
the same `contrib/` layout PRD 0048 established for the Gitea
deploy-key provisioner. The four provisioner methods backends
currently duplicate move into the provider plugin itself; the backend
keeps only the bottle-side primitives (`cp_in`, `exec`) the plugin
calls through. MCP server registration becomes a first-class part of
the provider contract so Codex finally gets the supervise sidecar
wired in alongside Claude.

The shipping artifact is two new provider plugins under `contrib/`, a
narrower `AgentProvider` ABC in `bot_bottle/agent_provider.py`, four
fewer provisioner hooks on `BottleBackend`, and a supervise-MCP entry
visible from the Codex agent at launch.

## Problem

Three concrete pains, all downstream of the provider abstraction not
being where the work happens:

1. **Adding a third provider is a five-file edit.** A hypothetical
   Gemini or Aider provider has to: (a) add a branch in
   `agent_provision_plan`, (b) add a runtime entry in `_RUNTIMES`,
   (c) thread a `prompt_mode` enum value, (d) potentially extend
   `provision_provider_auth` per backend, (e) wire MCP registration
   into both `backend/docker/provision/supervise.py` and
   `backend/smolmachines/provision/supervise.py`. Nothing about that
   spread is load-bearing; it's leftover from when there was one
   provider.

2. **MCP server registration is Claude-only.** Both
   `backend/docker/provision/supervise.py` and
   `backend/smolmachines/provision/supervise.py` run `claude mcp add`
   verbatim. Codex bottles silently get no MCP entry — the sidecar
   is running, the routes are open, but the agent can't see the
   tools because nothing wrote them into Codex's TOML config. Today
   this is a latent gap. The provider plugin is the only layer that
   knows how a given agent discovers MCP servers, so that's where
   the registration belongs.

3. **`provision_skills` / `provision_prompt` / `provision_provider_auth`
   are duplicated between backends.** Each backend has its own
   ~50-line copy. The differences are entirely about which path the
   backend uses for `cp_in` and what user it `chown`s to. Same
   business logic, two implementations, two test surfaces, two
   places to update when the rules change.

The agent_provider module is the right home for all of this. It already
owns the `AgentProvisionPlan` (the declarative description of what
needs to land in the guest); extending it to own the imperative
"actually land it" step is the natural next move. Putting
provider-specific code under `contrib/` mirrors the convention PRD 0048
established and keeps the core package provider-agnostic.

## Goals / Success Criteria

1. `bot_bottle/agent_provider.py` contains no Claude- or
   Codex-specific branches. The Claude and Codex template strings
   themselves still live in the core module (they're the public
   manifest values), but everything keyed off them moves out.
2. `bot_bottle/contrib/claude/agent_provider.py` and
   `bot_bottle/contrib/codex/agent_provider.py` exist and contain
   the provider-specific behavior previously in lines 154–230 of
   `agent_provider.py`. Each is reachable from the core registry via
   a lazy import (the same pattern PRD 0048 used for
   `GiteaDeployKeyProvisioner`).
3. `AgentProvider` is an ABC (or protocol) with at minimum:
   - `provision_plan(...) -> AgentProvisionPlan` — what the existing
     `agent_provision_plan` produces today, scoped to one provider.
   - `provision_skills(bottle, plan)` — copy host skills into the guest.
   - `provision_prompt(bottle, plan)` — copy the prompt file, return
     the in-guest path (or None).
   - `provision_supervise_mcp(bottle, plan, supervise_url)` — register
     the supervise sidecar in the provider's MCP config. No-op when
     the bottle has no supervise sidecar.
   - The Claude implementation runs `claude mcp add`. The Codex
     implementation writes the corresponding entry into
     `~/.codex/config.toml`'s `[mcp_servers.supervise]` table.
4. `BottleBackend` loses the four abstract methods being moved
   (`provision_skills`, `provision_prompt`, `provision_provider_auth`,
   `provision_supervise`). `BottleBackend.provision_in_bottle` calls
   the provider plugin directly via the bottle and plan it already
   has. `provision_ca`, `provision_workspace`, and `provision_git`
   stay on the backend — they're backend infrastructure, not
   provider behavior.
5. `bot_bottle/backend/docker/provision/{skills,prompt,provider_auth,
   supervise}.py` and `bot_bottle/backend/smolmachines/provision/{skills,
   prompt,provider_auth,supervise}.py` are deleted. The
   backend-specific provisioners that remain (`ca`, `git`,
   `workspace`) stay.
6. A Codex bottle launched with `--supervise` shows the
   supervise MCP server entry in its Codex config and can call
   supervise tools from inside the bottle (egress-block,
   pipelock-block, capability-block).
7. Existing tests for the moved logic move with the code:
   provider-specific tests under `tests/unit/test_contrib_claude_*.py`
   and `tests/unit/test_contrib_codex_*.py`, mirroring
   `tests/unit/test_contrib_gitea_deploy_key.py`.
8. PRD 0050's Status flips Draft → Active in the same commit that
   removes the last `if template == "claude"` branch from
   `agent_provider.py`.

## Non-goals

- **A third agent provider.** This PRD reshapes the boundary so a
  third provider is cheap to add. It does not add one.
- **Changing the manifest surface.** The `agent.provider`
  manifest field still takes `"claude"` or `"codex"`. The set of
  valid strings is unchanged.
- **Changing `AgentProvisionPlan`'s shape.** The dataclasses
  (`AgentProvisionDir`, `AgentProvisionFile`, `AgentProvisionCommand`,
  `AgentProvisionPlan` itself) stay in the core module and keep their
  current fields. Provider plugins produce the same plan shape; only
  the producer moves.
- **Changing the supervise sidecar protocol or the supervise tool
  surface.** PRDs 0013–0016 stay Active. What changes is how the
  agent discovers the sidecar's MCP endpoint, not what it does once
  connected.
- **Per-skill provider differences.** A Codex agent and a Claude
  agent see the same `~/.claude/skills/<name>/` tree today (Codex
  reads it via its own skills mechanism). This PRD does not change
  that — `provision_skills` lands the same content for both.
- **Removing the `prompt_args` helper from `agent_provider.py`.** It
  stays at module scope; it's already a pure dispatch on `prompt_mode`
  and has no Claude/Codex `if` chain to extract.
- **`provision_provider_auth` migration.** The issue notes this method
  is "probably not needed anymore" once each provider owns its own
  provisioning. After the move, the work that
  `provision_provider_auth` did (apply `dirs` / `files` / `pre_copy` /
  `verify` from the plan) becomes a shared helper the per-provider
  `provision_skills` / `provision_prompt` calls dispatch through —
  or, more likely, a single `provision(bottle)` entry point on the
  provider. The hook is removed from `BottleBackend`; whether the
  underlying loop lives on `AgentProvider` as a default
  implementation or as a free function in `contrib/_apply.py` is
  decided at implementation time, not in this PRD.

## Scope

### In scope

- New `AgentProvider` ABC in `bot_bottle/agent_provider.py` with the
  five methods listed under Goal 3. Existing `agent_provision_plan`
  becomes `AgentProvider.provision_plan`.
- New `bot_bottle/contrib/claude/__init__.py`,
  `bot_bottle/contrib/claude/agent_provider.py`,
  `bot_bottle/contrib/codex/__init__.py`,
  `bot_bottle/contrib/codex/agent_provider.py`. Each defines a
  `ClaudeAgentProvider` / `CodexAgentProvider` class.
- A `get_provider(template) -> AgentProvider` registry in
  `bot_bottle/agent_provider.py`, lazy-imported from `contrib/`,
  mirroring `get_provisioner(provider, ...)` in
  `bot_bottle/deploy_key_provisioner.py`.
- Backend changes:
  - `BottleBackend.provision_in_bottle` resolves the provider once
    and calls `provider.provision_skills(bottle, plan)`,
    `provider.provision_prompt(bottle, plan)`, and
    `provider.provision_supervise_mcp(bottle, plan, url)` in place
    of the current four abstract hooks.
  - `BottleBackend.provision_skills`, `provision_prompt`,
    `provision_provider_auth`, `provision_supervise` are removed.
  - Docker and smolmachines backends remove their corresponding
    `provision_*` implementations and the
    `backend/<name>/provision/{skills,prompt,provider_auth,
    supervise}.py` modules.
- Codex MCP wiring: `CodexAgentProvider.provision_supervise_mcp`
  writes a `[mcp_servers.supervise]` block into
  `~/.codex/config.toml` pointing at the same agent-side supervise
  URL the Claude provider uses. The file already exists from the
  trust-dialog step; the MCP entry is appended (or the file is
  rewritten in a single shot, whichever's simpler).
- Tests migrate. Backend tests that targeted the four moved
  provisioners are rewritten against the provider plugin, with one
  test file per provider mirroring `tests/unit/test_contrib_gitea_*.py`.

### Out of scope

- Adding a manifest field for "extra MCP servers the agent should
  see". The supervise sidecar is the only MCP server provisioned
  today, and the issue's "Add mcp server configuring into agent
  provision" line is about the supervise sidecar specifically. A
  general-purpose user-declared MCP list is a follow-up if and when
  the need surfaces.
- Refactoring `AgentProvisionPlan`'s dataclasses. They stay byte-
  for-byte the same so the diff is purely "who owns the producer".
- A `BottleBackend.provision_provider_auth` shim during transition.
  The hook is removed in one cut; the only caller is the backend
  itself, no manifest consumers reference it.
- Renaming `agent_provider.py` → `agent_providers/`. The module
  still has core dataclasses + the ABC + the registry; it's a single
  file's worth of code.

## Proposed design

### Module shape after the cut

```
bot_bottle/agent_provider.py
  PROVIDER_CLAUDE, PROVIDER_CODEX, PROVIDER_TEMPLATES
  PromptMode  (Literal)
  AgentProvisionDir, AgentProvisionFile, AgentProvisionCommand,
    AgentProvisionPlan  (dataclasses, unchanged)
  AgentProviderRuntime  (dataclass — template/command/image/etc.)
  AgentProvider  (ABC)
    .runtime() -> AgentProviderRuntime
    .provision_plan(state_dir, ..., trusted_project_path, ...) -> AgentProvisionPlan
    .provision_skills(bottle, plan) -> None
    .provision_prompt(bottle, plan) -> str | None
    .provision_supervise_mcp(bottle, plan, supervise_url) -> None
  get_provider(template: str) -> AgentProvider     # lazy-imports contrib
  prompt_args(prompt_mode, prompt_path, *, argv)   # unchanged

bot_bottle/contrib/claude/agent_provider.py
  ClaudeAgentProvider(AgentProvider)
    _RUNTIME = AgentProviderRuntime(template="claude", ...)
    .provision_plan(...)         # owns the lines-204–230 chunk
    .provision_skills(...)       # was backend/<name>/provision/skills.py
    .provision_prompt(...)       # was backend/<name>/provision/prompt.py
    .provision_supervise_mcp(...)# was backend/<name>/provision/supervise.py

bot_bottle/contrib/codex/agent_provider.py
  CodexAgentProvider(AgentProvider)
    _RUNTIME = AgentProviderRuntime(template="codex", ...)
    .provision_plan(...)         # owns the lines-154–204 chunk
    .provision_skills(...)       # same as Claude impl, factored to shared helper
    .provision_prompt(...)       # same as Claude impl, factored to shared helper
    .provision_supervise_mcp(...)# writes [mcp_servers.supervise] to config.toml
```

The skills / prompt / provider-auth-apply implementations are 99%
identical across providers — `cp_in` then `chown` / `chmod`. They are
extracted to small free functions in
`bot_bottle/contrib/_provision_apply.py` (or kept as default
implementations on `AgentProvider` if every concrete subclass would
just call them). Picked at implementation time; both options match
PRD 0048's contrib convention. The visible contract is that
provisioning lives on the provider plugin.

### MCP registration for Codex

Codex reads MCP servers from `~/.codex/config.toml` (or whatever
`CODEX_HOME/config.toml` resolves to). The provider already writes
this file once during `provision_plan` to set the project trust
level. `CodexAgentProvider.provision_supervise_mcp` extends the
existing write: same path, append a `[mcp_servers.supervise]` table
pointing at the agent-side supervise URL.

Two implementation routes worth flagging:

- **Option A:** Pre-bake the MCP entry in the same config-write that
  happens during `provision_plan`, before bottle launch. Simpler;
  the supervise URL has to be known at plan time, which means
  `provision_plan` needs the supervise URL (or a sentinel that means
  "fill this in"). The smolmachines backend already plumbs
  `agent_supervise_url` through to its provision_supervise step, so
  the value is available.
- **Option B:** Append at bottle-launch time via a `bottle.exec`
  that writes to the file inside the guest, matching the
  `claude mcp add` flow. Slower but uniform with how
  `ClaudeAgentProvider.provision_supervise_mcp` works.

Option B is the symmetric choice and the one this PRD assumes.
The implementer can switch to A if Option B turns out to need a
TOML-merge primitive the codebase doesn't already have.

### Backend after the cut

```python
class BottleBackend:
    def provision_in_bottle(self, plan, bottle, supervise_url):
        provider = get_provider(plan.spec.manifest.agents[
            plan.spec.agent_name].provider)
        self.provision_ca(plan, bottle)
        prompt_path = provider.provision_prompt(bottle, plan)
        provider.provision_skills(bottle, plan)
        self.provision_workspace(plan, bottle)
        self.provision_git(plan, bottle)
        provider.provision_supervise_mcp(bottle, plan, supervise_url)
        return prompt_path
```

`supervise_url` is the existing per-backend "where does the agent
reach the sidecar from inside the guest" value. The Docker backend
passes `http://supervise:<port>/`; smolmachines passes the
`http://127.0.0.1:<port>/` it already computed. The backend's only
remaining provider-touching duty is "tell the provider what the
sidecar URL is".

### Registry

```python
# bot_bottle/agent_provider.py
def get_provider(template: str) -> AgentProvider:
    if template == PROVIDER_CLAUDE:
        from bot_bottle.contrib.claude.agent_provider import (
            ClaudeAgentProvider,
        )
        return ClaudeAgentProvider()
    if template == PROVIDER_CODEX:
        from bot_bottle.contrib.codex.agent_provider import (
            CodexAgentProvider,
        )
        return CodexAgentProvider()
    raise ValueError(f"unknown agent provider template: {template!r}")
```

Lazy imports keep core import-time graph small and match PRD 0048.

## Implementation chunks

Each chunk is one commit on the PR; the PR ships as one cut.

1. **Lift `AgentProvider` ABC + registry.** Add the ABC and
   `get_provider` next to the existing `agent_provision_plan`
   function. Have `agent_provision_plan` delegate to
   `get_provider(template).provision_plan(...)` so callers keep
   working through the transition.
2. **Move provider-specific `provision_plan` content into
   contrib.** Create `contrib/claude/` and `contrib/codex/`. The
   Claude and Codex branches of `agent_provision_plan` move into
   the respective provider classes. The shared scaffolding
   (initial dict setup, final `AgentProvisionPlan(...)` return)
   stays in the ABC as a template method or moves into each
   subclass — whichever needs less indirection.
3. **Move backend provisioners onto the provider.** Add
   `provision_skills`, `provision_prompt`, `provision_supervise_mcp`
   to `AgentProvider` (with a shared apply helper for skills /
   prompt). Update `BottleBackend.provision_in_bottle` to call them.
   Delete the four backend hook methods and the eight
   `backend/<name>/provision/{skills,prompt,provider_auth,supervise}.py`
   modules.
4. **Add Codex MCP support.** Implement
   `CodexAgentProvider.provision_supervise_mcp` against
   `~/.codex/config.toml`. Add a unit test that runs the method
   against an in-memory FakeBottle and asserts the
   `[mcp_servers.supervise]` block is present.
5. **Migrate tests.** Per-backend tests for the moved
   provisioners turn into per-provider tests under
   `tests/unit/test_contrib_claude_*.py` and
   `tests/unit/test_contrib_codex_*.py`. Keep one integration-style
   test per backend that confirms `provision_in_bottle` still
   reaches every step.
6. **Activate.** Flip Status: Draft → Active in this PRD; close
   #177 on merge.

## Open questions (resolved)

1. **`codex mcp add` exists.** Implementation calls
   `codex mcp add --transport http supervise <url>` as `node` —
   symmetric with `claude mcp add` (no `--scope user`; Codex writes
   `~/.codex/config.toml` by default). Failure logs a warning; the
   bottle still works without the entry.
2. **Each provider owns its apply steps end-to-end.** The base
   ABC declares `provision_skills` / `provision_prompt` /
   `provision` as abstract; each concrete provider implements its
   own copy loop. No shared `_provision_apply.py`. The apply
   sequences look similar today, but Claude and Codex harnesses
   diverge over time (codex already grew a dummy-auth dance + a
   `codex login status` verify with no Claude analogue) and the
   "shared because both happen to call cp_in then chown" coupling
   would just rot. Duplication is intentional.
3. **Env knobs removed.** `BOT_BOTTLE_CONTAINER_HOME`,
   `BOT_BOTTLE_GUEST_HOME`, `BOT_BOTTLE_CONTAINER_SKILLS_DIR`, and
   `BOT_BOTTLE_GUEST_SKILLS_DIR` are gone; `/home/node` is hardcoded
   everywhere it was read. The values were effectively constants;
   the knobs added surface area for no real flexibility.

## References

- Issue
  [#177](https://gitea.dideric.is/didericis/bot-bottle/issues/177)
  — the request: move provider logic into contrib, add MCP
  configuration to agent provision, rename provision_supervise →
  provision_supervise_mcp, ensure Codex gets MCP provisioned.
- PRD 0013 — supervise plane foundation (defines the MCP-discoverable
  block-remediation tools this PRD makes available to Codex).
- PRD 0048 — SSH deploy key provisioning (the `contrib/` convention
  this PRD follows).
- Current source:
  [agent_provider.py L154-L230](https://gitea.dideric.is/didericis/bot-bottle/src/branch/main/bot_bottle/agent_provider.py#L154-L230)
  — the provider-specific block this PRD relocates to contrib.