Source: https://internal-agents.com/agents/shopify-internal-agents # Shopify — Aquifer / River The Aquifer agent platform (session/harness/sandbox split) powers River, a Slack-native coding agent, plus research, migration, and app-security agents. > This entry describes supporting infrastructure that other work builds on. The catalog classifies it as a platform. The record also reports a workflow. - Approach type: Platform - Deployment stage: Scaled - Autonomy: Drafts reviewed - Evidence strength: Detailed primary - Status: Internal - First reported year: 2026 - Work: Coding, Code review, Research, Security - Interfaces: Slack, Github - Invocation: Event driven, Interactive - Entry reviewed: 2026-09-09 ## Where people stay involved - **River coding request → reviewed pull request** — Work product review · Level 3 ## Overview ### Summary The Aquifer agent platform (session/harness/sandbox split) powers River, a Slack-native coding agent, plus research, migration, and app-security agents. Fact · Reported · High confidence · `shopify-internal-agents--summary` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ## How it works ### Supporting component Durable identity, disposable loop, isolated execution; swap any layer independently Fact · Reported · High confidence · `shopify-internal-agents--primitives-0` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Supporting component Slack-native coding agent in public channels only; visibility drives adoption Fact · Reported · High confidence · `shopify-internal-agents--primitives-1` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Supporting component Written-down knowledge mined from successful patterns and public transcripts Fact · Reported · High confidence · `shopify-internal-agents--primitives-2` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ## Supervision evidence ### Operating model assessment Level 3 for River coding request → reviewed pull request; human attention boundary: work-product-review. Inference · Catalog judgment · Medium confidence · `shopify-internal-agents--operating-models-0` Confidence reason: The source documents pull-request creation but does not establish outcome-only supervision. Qualifications: - Observation date: 2026 Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ## Implementation details ### Sandbox An execution environment (filesystem, shell, repo, build/test) separated from the harness; Shopify credits the brain-and-hands framing to Anthropic Fact · Reported · High confidence · `shopify-internal-agents--architecture-sandbox` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Harness Session (durable; Postgres append-only event log) + Harness (cheap agent loop) + Cell (ephemeral Go runtime); cells die, sessions persist Fact · Reported · High confidence · `shopify-internal-agents--architecture-harness` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Model The design lets Shopify change the model without changing the sandbox Fact · Reported · High confidence · `shopify-internal-agents--architecture-model` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Interfaces slack, github Fact · Reported · High confidence · `shopify-internal-agents--architecture-interfaces` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Tool access Repo + tests + data warehouse + production traces + PR creation; a gateway credentials proxy Fact · Reported · High confidence · `shopify-internal-agents--architecture-tool-access` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Knowledge Monorepo 'World' (code + skills + conventions + intent docs + runbooks + AGENTS.md); Nix reproducible envs; Slack-transcript corpus mining Fact · Reported · High confidence · `shopify-internal-agents--architecture-knowledge` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Credentials Gateway credentials proxy; per-profile sandbox policies; Shopify SSO Fact · Reported · High confidence · `shopify-internal-agents--architecture-credentials` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Context management Skills loaded on-demand as files, updatable per session; session survival across cell/sandbox/machine death Fact · Reported · High confidence · `shopify-internal-agents--architecture-context-mgmt` Confidence reason: A linked first-party source states the claim. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ## Reported metrics ### Headline claim 1 in 8 merged PRs company-wide coauthored by River Metric · Reported · High confidence · `shopify-internal-agents--headline-metric` Confidence reason: A linked first-party source states the claim. Qualifications: - Reported by: Shopify - Scope: Merged River-coauthored PRs across Shopify - Denominator: All Shopify merged pull requests Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) · Preserved content.md, lines 12 ### Key observation River: 59,918 sessions / 30 days across 5,170 Slack channels Metric · Reported · High confidence · `shopify-internal-agents--key-metrics-0` Confidence reason: A linked first-party source states the claim. Qualifications: - The source does not report the denominator of this figure. - Reported by: Shopify - Scope: River sessions and distinct Slack channels in a recent 30-day period - Method: river_sessions domain table, written by River every session Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) · Preserved content.md, lines 83 ### Key observation 3,536 River-coauthored PRs merged; 1 in 8 merged PRs company-wide Metric · Reported · High confidence · `shopify-internal-agents--key-metrics-1` Confidence reason: A linked first-party source states the claim. Qualifications: - Reported by: Shopify - Scope: River-coauthored merged PRs in the recent 30-day period; company-wide PR share - Denominator: All Shopify merged pull requests for the one-in-eight share - Method: river_sessions domain table for reported session-linked counts Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) · Preserved content.md, lines 12, 83 ### Key observation Median session 19 min; median 50 tool calls/session Metric · Reported · High confidence · `shopify-internal-agents--key-metrics-2` Confidence reason: A linked first-party source states the claim. Qualifications: - The source does not report the denominator of this figure. - Reported by: Shopify - Scope: Median River session duration and tool calls per session Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) · Preserved content.md, lines 65 ## Lessons and interpretation ### Lesson Agent-friendly is human-friendly; monorepo, reproducible envs, written skills, and fast CI help both Inference · Catalog judgment · Medium confidence · `shopify-internal-agents--lessons-learned-0` Confidence reason: The catalog derives this observation from the linked sources. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Lesson Local agents have a ceiling; private windows mean only the person at the keyboard learns anything Inference · Catalog judgment · Medium confidence · `shopify-internal-agents--lessons-learned-1` Confidence reason: The catalog derives this observation from the linked sources. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Lesson Session survival is critical; cells die, sandboxes die, machines die; the conversation doesn't Inference · Catalog judgment · Medium confidence · `shopify-internal-agents--lessons-learned-2` Confidence reason: The catalog derives this observation from the linked sources. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ### Lesson Treat agents as profiles, not platforms; a new agent is a new bundle on the same substrate Inference · Catalog judgment · Medium confidence · `shopify-internal-agents--lessons-learned-3` Confidence reason: The catalog derives this observation from the linked sources. Evidence: - Supports · [1] [Under the River](https://shopify.engineering/under-the-river) · [Preserved copy](https://github.com/steel-experiments/internal-agents-map/blob/main/archive/sources/shopify-internal-agents-source-1/content.md) ## Sources 1. [Under the River](https://shopify.engineering/under-the-river) - Engineering blog · First party · Evidence - Original URL: - Accessed: 2026-08-12 · Last verified: 2026-08-31 - Preserved copy in the repository: