Skip to content

devin-provider.md

Latest commit

 

History

History
159 lines (125 loc) · 7.85 KB

devin-provider.md

File metadata and controls

159 lines (125 loc) · 7.85 KB
Raw

Devin CLI provider (ACP)

GJC can drive Devin CLI as a selectable provider. Devin is integrated through its Agent Client Protocol server (devin acp), because that is the only programmatic interface Devin CLI exposes: Devin publishes no model-inference endpoint, and its CLI credentials cannot be reused for arbitrary inference requests.

That makes devin an agent-level provider, not a model backend. This page states exactly what that means for tools, permissions, workflows, and billing.

Setup

# 1. Install Devin CLI and authenticate (credentials stay with Devin).
#    https://docs.devin.ai/cli
devin auth login

# 2. Confirm the CLI is reachable. GJC spawns `devin acp` over stdio.
devin models list

# 3. Start GJC and pick a Devin model.
gjc
#   /model          -> provider model picker
#   gjc models      -> non-interactive model list

If devin is not on PATH, point GJC at the executable:

GJC_DEVIN_CLI_PATH=/opt/devin/bin/devin gjc

Models

GJC discovers the models your account can use from the ACP session's own model config option and applies the model you select with the session's session/set_config_option request. The catalog therefore follows your Devin account and enterprise allowlists instead of a hardcoded list. adaptive is the default selector when no model has been chosen yet (Devin's recommended default); enterprise organizations can disable it.

Selecting a model the account does not offer fails loudly with the account's actual options rather than silently running a different (possibly more expensive) model. If you switch models mid-session, GJC applies the change to the live ACP session.

What applies to a Devin turn

Surface Applies?
GJC TUI, transcript rendering, session persistence, resume Yes
Provider/model selection (/model, gjc models, role profiles) Yes
Cancelling a turn (Esc/Ctrl+C) Yes — GJC sends ACP session/cancel
Devin's own tool calls shown in the transcript Yes, read-only (see below)
GJC tools (bash, read, edit, grep, task, web search, LSP, …) No — Devin runs its own tools
GJC skills, workflows (deep-interview, ralplan, ultragoal, autoresearch), role agents, hooks No — they are not sent to Devin
GJC permission prompts for GJC tools No — see "Permissions"
GJC context compaction, handoff, branch summaries No — refused up front, never sent to Devin
GJC token accounting, cost display, context-window pressure No — Devin reports its own usage

Why GJC tools do not participate

A GJC model provider returns an assistant message whose tool calls GJC then executes. ACP works the other way around: the agent executes its tools and reports them to the client. GJC therefore renders Devin's tool_call / tool_call_update notifications as read-only transcript entries and always finishes the turn with a normal stop, so GJC never re-executes a Devin tool call. Each entry carries its ACP identity under an _acp key (toolCallId, kind, status) in its arguments.

Devin owns the conversation history. GJC forwards only your newest message, and Devin applies its own rules (AGENTS.md, .devin/ rules and skills, MCP servers you configured with devin mcp). GJC's own AGENTS.md-driven harness guidance is not injected into Devin turns.

Maintenance and utility calls are refused

GJC also routes non-turn work through a provider: context compaction, handoff generation, branch summaries, and utility generations such as session titles, commit messages, and prompt suggestions. Devin is an agent, not a text model, so GJC refuses those requests instead of spending your Devin quota on them, with an error naming what happened (maintenanceCall on the provider request).

A Devin turn therefore requires an interactive GJC session turn: a session identity plus a user message. Utility one-shots that carry no session identity are rejected the same way.

This rarely matters in practice: because GJC forwards only your newest message, Devin manages the conversation context itself, so GJC-side compaction is not needed to keep a Devin session going. GJC's own transcript can still reach its auto-compaction threshold on a long session; when every model the maintenance action could reach is an agent-level provider, GJC skips it quietly instead of reporting a guaranteed refusal on every crossing. Manual maintenance (/compact, /handoff, branch summaries) still reports the refusal — switch to a non-Devin model (/model) for that operation. Auto-compaction can also run when a non-Devin model stays reachable (e.g. the default role resolves to a text model while the session itself is on Devin) or a session_before_compact extension hook supplies the summary.

Images

Image attachments are forwarded only when the ACP agent advertises image prompt support (an ACP promptCapabilities negotiation). Otherwise the attachment is replaced with a visible note in the prompt, so nothing is dropped silently.

Permissions

Devin asks the ACP client — GJC — before running the operations its own permission policy gates. GJC answers from an explicit policy:

GJC_DEVIN_PERMISSION_MODE Behavior
unset / allow (default) Grants allow_once. A request that offers no allow_once is cancelled: GJC never grants a persistent approval on its own.
deny Reject with reject_once (or reject_always when that is the only refusal offered).
any other value Fails closed to deny.

If Devin offers no option matching the policy, GJC answers cancelled rather than approving something it was not offered.

This policy mirrors GJC's own stance for its own tools: GJC is an autonomous coding agent and does not prompt for every tool call. Set GJC_DEVIN_PERMISSION_MODE=deny for untrusted repositories, or configure Devin's own permission mode (devin --permission-mode, DEVIN_PERMISSION_MODE) so it does not ask in the first place.

Billing

Devin usage is billed to your Devin account (quota/credits or ACUs, depending on your plan). GJC records zero cost for Devin turns and does not convert Devin usage into GJC token accounting; use Devin's /usage or /session-stats inside a session for that.

Troubleshooting

Symptom Cause and fix
Provider shows no models Devin CLI missing, unauthenticated, or off PATH. Run devin auth login; set GJC_DEVIN_CLI_PATH if needed.
Devin CLI is not authenticated GJC reached the CLI but it has no credentials. Run devin auth login (or set WINDSURF_API_KEY for enterprise builds).
Devin account does not offer model "<id>" The model is not in your account's allowlist. Pick a discovered model.
Devin ACP process exited with code … The CLI crashed; the stderr tail is included in the message.
Turn stalls then errors The agent stopped sending updates within the stream idle timeout. Check devin doctor/devin --version.
Error naming maintenance calls GJC refused a manual compaction/handoff/branch-summary request on a Devin model (auto-maintenance skips quietly). Switch to a non-Devin model for that operation.

Implementation notes

  • Provider id devin, API devin-acp, implemented in packages/ai/src/providers/devin-acp.ts.
  • One devin acp child process per GJC session and working directory, reused across turns and killed at session teardown (providerSessionState). The working directory is part of that cache identity, so /move starts a fresh ACP session in the new directory (Devin's own conversation history restarts, as it would for a new session) and closes the child it replaced.
  • Authentication, model catalog, tool execution, and usage stay inside Devin; GJC never reads or stores Devin credentials.

See also: Models and providers, Environment variables.