GitHub Copilot CLI

Persistent memory for GitHub Copilot CLI using Hindsight. Python hook scripts automatically recall relevant context at session start (and for every subagent Copilot CLI spawns) and retain conversations as they happen — no changes to your Copilot CLI workflow required.

Quick Start

Recommended: Hindsight Cloud

Sign up free for a Hindsight Cloud API key — no self-hosting, no local daemon to manage.

# Install the CLI
pip install hindsight-copilot-cli

# Install the hooks (defaults to Hindsight Cloud)
hindsight-copilot-cli install --api-url https://api.hindsight.vectorize.io --api-token your-api-key

# Restart Copilot CLI — memory is live

The installer copies the hook scripts to ~/.copilot/hindsight-copilot-cli/, writes a standalone ~/.copilot/hooks/hindsight-copilot-cli.json (Copilot CLI loads every *.json file in its hooks directory, so this never needs to merge with other tools' hook files), and creates ~/.hindsight/copilot-cli.json for your personal config.

Self-hosting alternative — connect to a local hindsight-embed daemon by omitting the flags:

hindsight-copilot-cli install

To uninstall:

hindsight-copilot-cli uninstall

Repo-level install

For a team-shared configuration checked into version control, register the hooks at the repository level instead:

hindsight-copilot-cli install --scope repo

This writes .github/hooks/hindsight-copilot-cli.json in the current repo. Hook scripts are still installed to ~/.copilot/hindsight-copilot-cli/ (per-machine), so the token must come from the HINDSIGHT_API_TOKEN environment variable rather than a committed file.

Features

• Auto-recall at session start — when a Copilot CLI session starts, queries Hindsight for relevant memories and injects them as additional context. Uses the queued initialPrompt when one exists, or falls back to a generic project-context query derived from the working directory.
• Auto-recall for subagents — Copilot CLI's built-in subagents (explore, task, research, code-review, rubber-duck, security-review, and custom agents) run in their own isolated context and otherwise get none of the memory injected at session start. The subagentStart hook gives them baseline project memory too.
• Auto-retain — after each turn (subject to retainEveryNTurns), and again on session end, stores the conversation to Hindsight for future recall.
• Dynamic bank IDs — supports per-project memory isolation based on the working directory.
• Session-level upsert — uses the session ID as the document ID so re-running the same session updates rather than duplicates stored content.
• Zero runtime dependencies — the hook scripts are pure Python stdlib; the pip install only ships the one-time installer.

Architecture

The plugin uses four Copilot CLI hook events:

Hook	Event	Purpose
session_start.py	sessionStart	Auto-recall — query memories using the initial prompt (or a project-context fallback), inject as additional context
subagent_start.py	subagentStart	Auto-recall for subagents — query memories using a project-context fallback query (subagent payloads carry no task text), inject as additional context
agent_stop.py	agentStop	Auto-retain — read the transcript, apply the retainEveryNTurns cadence, POST to Hindsight (async); caches the transcript path for sessionEnd
session_end.py	sessionEnd	Final flush — force a retain using the transcript path cached by the last agentStop, since sessionEnd's payload has no transcript path of its own

On sessionStart, the hook queries Hindsight for the most relevant memories and injects a context block that Copilot CLI adds to the session:

<hindsight_memories>
Relevant memories from past conversations...
Current time - 2026-03-27 09:14

- Project uses FastAPI with asyncpg — not SQLAlchemy [world] (2026-03-26)
- Preferred testing framework: pytest with pytest-asyncio [experience] (2026-03-26)
</hindsight_memories>

subagentStart fires for every subagent Copilot CLI spawns except the built-in general-purpose agent (which never emits the event) and injects the same style of context block, prepended to that subagent's prompt.

On agentStop (and again on sessionEnd), the hook reads the session transcript, strips previously injected memory tags (to prevent feedback loops), and POSTs the conversation to Hindsight asynchronously.

Recall is not refreshed per turn

Unlike some other integrations, Copilot CLI's userPromptSubmitted and preToolUse hooks don't support injecting additional context, so recall only runs once per session (at sessionStart) and once per subagent (at subagentStart) rather than being refreshed on every turn. This keeps the integration simple and reliable, at the cost of not picking up new memories mid-session.

Connection Modes

1. External API (recommended)

Connect to a running Hindsight server (cloud or self-hosted) via ~/.hindsight/copilot-cli.json:

{
  "hindsightApiUrl": "https://api.hindsight.vectorize.io",
  "hindsightApiToken": "hsk_your_token"
}

2. Local Daemon

Run hindsight-embed locally. The session_start.py hook detects it on apiPort (default 9077). The daemon is not auto-started by the plugin — start it separately:

uvx hindsight-embed

Then leave hindsightApiUrl empty in your config and the plugin connects to http://localhost:9077.

Configuration

Default config ships in ~/.copilot/hindsight-copilot-cli/settings.json. For personal overrides that survive updates, create ~/.hindsight/copilot-cli.json. Most settings can also be overridden via environment variable.

Loading order (later entries win):

1. Built-in defaults
2. Plugin settings.json (at ~/.copilot/hindsight-copilot-cli/settings.json)
3. User config (~/.hindsight/copilot-cli.json)
4. Environment variables

---

Connection

Setting	Env Var	Default	Description
hindsightApiUrl	HINDSIGHT_API_URL	""	URL of the Hindsight API server. Empty = local daemon.
hindsightApiToken	HINDSIGHT_API_TOKEN	null	API token for authentication. Required for Hindsight Cloud.
apiPort	HINDSIGHT_API_PORT	9077	Port for the local hindsight-embed daemon.

---

Memory Bank

Setting	Env Var	Default	Description
bankId	HINDSIGHT_BANK_ID	"copilot-cli"	The bank to read from and write to. All sessions share this bank unless dynamicBankId is enabled.
bankMission	HINDSIGHT_BANK_MISSION	coding assistant prompt	Describes the agent's purpose. Sent when creating or updating the bank.
retainMission	—	extraction prompt	Instructions for Hindsight's fact extraction — what to extract from coding conversations.
dynamicBankId	HINDSIGHT_DYNAMIC_BANK_ID	false	When true, derives a unique bank ID from dynamicBankGranularity fields — useful for per-project isolation.
dynamicBankGranularity	—	["agent", "project"]	Which fields to combine for dynamic bank IDs. "project" = working directory, "agent" = agent name.
agentName	HINDSIGHT_AGENT_NAME	"copilot-cli"	Agent name used in dynamic bank ID derivation.

---

Auto-Recall

Setting	Env Var	Default	Description
autoRecall	HINDSIGHT_AUTO_RECALL	true	Master switch for auto-recall (covers both sessionStart and subagentStart).
recallBudget	HINDSIGHT_RECALL_BUDGET	"mid"	Search depth: "low" (fast), "mid" (balanced), "high" (thorough).
recallMaxTokens	HINDSIGHT_RECALL_MAX_TOKENS	1024	Max tokens in the recalled memory block.
recallTypes	—	["world", "experience"]	Memory types to retrieve.
recallFallbackQueryTemplate	—	project-context prompt	Query used when there's no specific prompt/task text available (interactive sessionStart with no queued prompt, or any subagentStart).

---

Auto-Retain

Setting	Env Var	Default	Description
autoRetain	HINDSIGHT_AUTO_RETAIN	true	Master switch for auto-retain.
retainMode	HINDSIGHT_RETAIN_MODE	"full-session"	"full-session" sends the full transcript per session (upserted by session ID). "chunked" sends sliding windows every N turns.
retainEveryNTurns	—	10	Retain fires every N turns. 1 = every turn. Higher values reduce API calls.
retainContext	—	"copilot-cli"	Label identifying the source integration. Useful when multiple integrations write to the same bank.

---

Debug

Setting	Env Var	Default	Description
debug	HINDSIGHT_DEBUG	false	Enable verbose logging to stderr. All log lines are prefixed with [Hindsight].

Per-Project Memory

To give each project its own isolated memory bank, enable dynamic bank IDs:

{
  "dynamicBankId": true,
  "dynamicBankGranularity": ["agent", "project"]
}

With this config, running Copilot CLI in ~/projects/api and ~/projects/frontend stores and recalls memories separately. Bank IDs are derived from the working directory path.

Troubleshooting

Hooks not firing: check that ~/.copilot/hooks/hindsight-copilot-cli.json (or .github/hooks/hindsight-copilot-cli.json for repo scope) is valid JSON. Copilot CLI loads hook configuration when it starts, so restart the CLI after installing or updating hooks.

No memories recalled: Recall returns results only after something has been retained. Complete one Copilot CLI session first, then start a new one.

Memory not being stored: retainEveryNTurns defaults to 10 — the agentStop hook only fires a retain every 10 turns. While testing, add "retainEveryNTurns": 1 to ~/.hindsight/copilot-cli.json. The sessionEnd hook also forces a final retain when the session terminates.

Debug mode: Add "debug": true to ~/.hindsight/copilot-cli.json to see what Hindsight is doing on each turn.