fleet-memory/hindsight-docs/docs/developer/configuration.md

Configuration

Complete reference for configuring Hindsight services through environment variables.

Hindsight has two services, each with its own configuration prefix:

Service	Prefix	Description
API Service	HINDSIGHT_API_*	Core memory engine
Control Plane	HINDSIGHT_CP_*	Web UI

---

API Service

The API service handles all memory operations (retain, recall, reflect).

Database

Variable	Description	Default
HINDSIGHT_API_DATABASE_URL	PostgreSQL connection string	pg0 (embedded)
HINDSIGHT_API_DATABASE_SCHEMA	PostgreSQL schema name for tables	public
HINDSIGHT_API_RUN_MIGRATIONS_ON_STARTUP	Run database migrations on API startup	true

If not provided, the server uses embedded pg0 — convenient for development but not recommended for production.

The DATABASE_SCHEMA setting allows you to use a custom PostgreSQL schema instead of the default public schema. This is useful for:

• Multi-database setups where you want Hindsight tables in a dedicated schema
• Hosting platforms (e.g., Supabase) where public schema is reserved or shared
• Organizational preferences for schema naming conventions

# Example: Using a custom schema
export HINDSIGHT_API_DATABASE_URL=postgresql://user:pass@host:5432/dbname
export HINDSIGHT_API_DATABASE_SCHEMA=hindsight

Migrations will automatically create the schema if it doesn't exist and create all tables in the configured schema.

Database Connection Pool

Variable	Description	Default
HINDSIGHT_API_DB_POOL_MIN_SIZE	Minimum connections in the pool	5
HINDSIGHT_API_DB_POOL_MAX_SIZE	Maximum connections in the pool	100
HINDSIGHT_API_DB_COMMAND_TIMEOUT	PostgreSQL command timeout in seconds	60
HINDSIGHT_API_DB_ACQUIRE_TIMEOUT	Connection acquisition timeout in seconds	30

For high-concurrency workloads, increase DB_POOL_MAX_SIZE. Each concurrent recall/think operation can use 2-4 connections.

To run migrations manually (e.g., before starting the API), use the admin CLI:

hindsight-admin run-db-migration
# Or for a specific schema:
hindsight-admin run-db-migration --schema tenant_acme

LLM Provider

Variable	Description	Default
HINDSIGHT_API_LLM_PROVIDER	Provider: openai, anthropic, gemini, groq, ollama, lmstudio, vertexai	openai
HINDSIGHT_API_LLM_API_KEY	API key for LLM provider	-
HINDSIGHT_API_LLM_MODEL	Model name	gpt-5-mini
HINDSIGHT_API_LLM_BASE_URL	Custom LLM endpoint	Provider default
HINDSIGHT_API_LLM_MAX_CONCURRENT	Max concurrent LLM requests	32
HINDSIGHT_API_LLM_MAX_RETRIES	Max retry attempts for LLM API calls	10
HINDSIGHT_API_LLM_INITIAL_BACKOFF	Initial retry backoff in seconds (exponential backoff)	1.0
HINDSIGHT_API_LLM_MAX_BACKOFF	Max retry backoff cap in seconds	60.0
HINDSIGHT_API_LLM_TIMEOUT	LLM request timeout in seconds	120
HINDSIGHT_API_LLM_GROQ_SERVICE_TIER	Groq service tier: on_demand, flex, auto	auto

Provider Examples

# Groq (recommended for fast inference)
export HINDSIGHT_API_LLM_PROVIDER=groq
export HINDSIGHT_API_LLM_API_KEY=gsk_xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=openai/gpt-oss-20b
# For free tier users: override to on_demand if you get service_tier errors
# export HINDSIGHT_API_LLM_GROQ_SERVICE_TIER=on_demand

# OpenAI
export HINDSIGHT_API_LLM_PROVIDER=openai
export HINDSIGHT_API_LLM_API_KEY=sk-xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=gpt-4o

# Gemini
export HINDSIGHT_API_LLM_PROVIDER=gemini
export HINDSIGHT_API_LLM_API_KEY=xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=gemini-2.0-flash

# Anthropic
export HINDSIGHT_API_LLM_PROVIDER=anthropic
export HINDSIGHT_API_LLM_API_KEY=sk-ant-xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=claude-sonnet-4-20250514

# Vertex AI (Google Cloud)
export HINDSIGHT_API_LLM_PROVIDER=vertexai
export HINDSIGHT_API_LLM_MODEL=google/gemini-2.0-flash-001
export HINDSIGHT_API_LLM_VERTEXAI_PROJECT_ID=your-gcp-project-id
export HINDSIGHT_API_LLM_VERTEXAI_REGION=us-central1
# Optional: use ADC (gcloud auth application-default login) or provide service account key:
# export HINDSIGHT_API_LLM_VERTEXAI_SERVICE_ACCOUNT_KEY=/path/to/service-account-key.json

# Ollama (local, no API key)
export HINDSIGHT_API_LLM_PROVIDER=ollama
export HINDSIGHT_API_LLM_BASE_URL=http://localhost:11434/v1
export HINDSIGHT_API_LLM_MODEL=llama3

# LM Studio (local, no API key)
export HINDSIGHT_API_LLM_PROVIDER=lmstudio
export HINDSIGHT_API_LLM_BASE_URL=http://localhost:1234/v1
export HINDSIGHT_API_LLM_MODEL=your-local-model

# OpenAI-compatible endpoint
export HINDSIGHT_API_LLM_PROVIDER=openai
export HINDSIGHT_API_LLM_BASE_URL=https://your-endpoint.com/v1
export HINDSIGHT_API_LLM_API_KEY=your-api-key
export HINDSIGHT_API_LLM_MODEL=your-model-name

Vertex AI Setup

Google Cloud's Vertex AI provides OpenAI-compatible endpoints for Gemini models. Hindsight supports two authentication methods:

Prerequisites:

• GCP project with Vertex AI API enabled
• IAM role roles/aiplatform.user for your credentials

Environment Variables:

Variable	Description	Required
HINDSIGHT_API_LLM_VERTEXAI_PROJECT_ID	Your GCP project ID	Yes
HINDSIGHT_API_LLM_VERTEXAI_REGION	GCP region (e.g., us-central1)	No (default: us-central1)
HINDSIGHT_API_LLM_VERTEXAI_SERVICE_ACCOUNT_KEY	Path to service account JSON key file	No (uses ADC if not set)

Authentication Methods:

1. Application Default Credentials (ADC) - Recommended for development

   # Setup ADC
   gcloud auth application-default login
   
   # Configure Hindsight
   export HINDSIGHT_API_LLM_PROVIDER=vertexai
   export HINDSIGHT_API_LLM_MODEL=google/gemini-2.0-flash-001
   export HINDSIGHT_API_LLM_VERTEXAI_PROJECT_ID=your-project-id
   

2. Service Account Key - Recommended for production

   # Create service account and download key
   gcloud iam service-accounts create hindsight-api
   gcloud projects add-iam-policy-binding your-project-id \
     --member="serviceAccount:hindsight-api@your-project-id.iam.gserviceaccount.com" \
     --role="roles/aiplatform.user"
   gcloud iam service-accounts keys create key.json \
     --iam-account=hindsight-api@your-project-id.iam.gserviceaccount.com
   
   # Configure Hindsight
   export HINDSIGHT_API_LLM_PROVIDER=vertexai
   export HINDSIGHT_API_LLM_MODEL=google/gemini-2.0-flash-001
   export HINDSIGHT_API_LLM_VERTEXAI_PROJECT_ID=your-project-id
   export HINDSIGHT_API_LLM_VERTEXAI_SERVICE_ACCOUNT_KEY=/path/to/key.json
   

Authentication Priority: Hindsight tries ADC first, then falls back to service account key file if configured.

Token Management: Access tokens expire after 60 minutes. Hindsight automatically refreshes tokens every 50 minutes in the background.

Per-Operation LLM Configuration

Different memory operations have different requirements. Retain (fact extraction) benefits from models with strong structured output capabilities, while Reflect (reasoning/response generation) can use lighter, faster models. Configure separate LLM models for each operation to optimize for cost and performance.

Variable	Description	Default
HINDSIGHT_API_RETAIN_LLM_PROVIDER	LLM provider for retain operations	Falls back to HINDSIGHT_API_LLM_PROVIDER
HINDSIGHT_API_RETAIN_LLM_API_KEY	API key for retain LLM	Falls back to HINDSIGHT_API_LLM_API_KEY
HINDSIGHT_API_RETAIN_LLM_MODEL	Model for retain operations	Falls back to HINDSIGHT_API_LLM_MODEL
HINDSIGHT_API_RETAIN_LLM_BASE_URL	Base URL for retain LLM	Falls back to HINDSIGHT_API_LLM_BASE_URL
HINDSIGHT_API_RETAIN_LLM_MAX_CONCURRENT	Max concurrent requests for retain	Falls back to HINDSIGHT_API_LLM_MAX_CONCURRENT
HINDSIGHT_API_RETAIN_LLM_MAX_RETRIES	Max retries for retain	Falls back to HINDSIGHT_API_LLM_MAX_RETRIES
HINDSIGHT_API_RETAIN_LLM_INITIAL_BACKOFF	Initial backoff for retain retries (seconds)	Falls back to HINDSIGHT_API_LLM_INITIAL_BACKOFF
HINDSIGHT_API_RETAIN_LLM_MAX_BACKOFF	Max backoff cap for retain retries (seconds)	Falls back to HINDSIGHT_API_LLM_MAX_BACKOFF
HINDSIGHT_API_RETAIN_LLM_TIMEOUT	Timeout for retain requests (seconds)	Falls back to HINDSIGHT_API_LLM_TIMEOUT
HINDSIGHT_API_REFLECT_LLM_PROVIDER	LLM provider for reflect operations	Falls back to HINDSIGHT_API_LLM_PROVIDER
HINDSIGHT_API_REFLECT_LLM_API_KEY	API key for reflect LLM	Falls back to HINDSIGHT_API_LLM_API_KEY
HINDSIGHT_API_REFLECT_LLM_MODEL	Model for reflect operations	Falls back to HINDSIGHT_API_LLM_MODEL
HINDSIGHT_API_REFLECT_LLM_BASE_URL	Base URL for reflect LLM	Falls back to HINDSIGHT_API_LLM_BASE_URL
HINDSIGHT_API_REFLECT_LLM_MAX_CONCURRENT	Max concurrent requests for reflect	Falls back to HINDSIGHT_API_LLM_MAX_CONCURRENT
HINDSIGHT_API_REFLECT_LLM_MAX_RETRIES	Max retries for reflect	Falls back to HINDSIGHT_API_LLM_MAX_RETRIES
HINDSIGHT_API_REFLECT_LLM_INITIAL_BACKOFF	Initial backoff for reflect retries (seconds)	Falls back to HINDSIGHT_API_LLM_INITIAL_BACKOFF
HINDSIGHT_API_REFLECT_LLM_MAX_BACKOFF	Max backoff cap for reflect retries (seconds)	Falls back to HINDSIGHT_API_LLM_MAX_BACKOFF
HINDSIGHT_API_REFLECT_LLM_TIMEOUT	Timeout for reflect requests (seconds)	Falls back to HINDSIGHT_API_LLM_TIMEOUT
HINDSIGHT_API_CONSOLIDATION_LLM_PROVIDER	LLM provider for observation consolidation	Falls back to HINDSIGHT_API_LLM_PROVIDER
HINDSIGHT_API_CONSOLIDATION_LLM_API_KEY	API key for consolidation LLM	Falls back to HINDSIGHT_API_LLM_API_KEY
HINDSIGHT_API_CONSOLIDATION_LLM_MODEL	Model for consolidation operations	Falls back to HINDSIGHT_API_LLM_MODEL
HINDSIGHT_API_CONSOLIDATION_LLM_BASE_URL	Base URL for consolidation LLM	Falls back to HINDSIGHT_API_LLM_BASE_URL
HINDSIGHT_API_CONSOLIDATION_LLM_MAX_CONCURRENT	Max concurrent requests for consolidation	Falls back to HINDSIGHT_API_LLM_MAX_CONCURRENT
HINDSIGHT_API_CONSOLIDATION_LLM_MAX_RETRIES	Max retries for consolidation	Falls back to HINDSIGHT_API_LLM_MAX_RETRIES
HINDSIGHT_API_CONSOLIDATION_LLM_INITIAL_BACKOFF	Initial backoff for consolidation retries (seconds)	Falls back to HINDSIGHT_API_LLM_INITIAL_BACKOFF
HINDSIGHT_API_CONSOLIDATION_LLM_MAX_BACKOFF	Max backoff cap for consolidation retries (seconds)	Falls back to HINDSIGHT_API_LLM_MAX_BACKOFF
HINDSIGHT_API_CONSOLIDATION_LLM_TIMEOUT	Timeout for consolidation requests (seconds)	Falls back to HINDSIGHT_API_LLM_TIMEOUT

:::tip When to Use Per-Operation Config

• Retain: Use models with strong structured output (e.g., GPT-4o, Claude) for accurate fact extraction
• Reflect: Use faster/cheaper models (e.g., GPT-4o-mini, Groq) for reasoning and response generation
• Recall: Does not use LLM (pure retrieval), so no configuration needed :::

Example: Separate Models for Retain and Reflect

# Default LLM (used as fallback)
export HINDSIGHT_API_LLM_PROVIDER=openai
export HINDSIGHT_API_LLM_API_KEY=sk-xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=gpt-4o

# Use GPT-4o for retain (strong structured output)
export HINDSIGHT_API_RETAIN_LLM_MODEL=gpt-4o

# Use faster/cheaper model for reflect
export HINDSIGHT_API_REFLECT_LLM_PROVIDER=groq
export HINDSIGHT_API_REFLECT_LLM_API_KEY=gsk_xxxxxxxxxxxx
export HINDSIGHT_API_REFLECT_LLM_MODEL=llama-3.3-70b-versatile

Example: Tuning Retry Behavior for Rate-Limited APIs

# For Anthropic with tight rate limits (10k output tokens/minute)
export HINDSIGHT_API_LLM_PROVIDER=anthropic
export HINDSIGHT_API_LLM_API_KEY=sk-ant-xxxxxxxxxxxx
export HINDSIGHT_API_LLM_MODEL=claude-sonnet-4-20250514

# Reduce concurrent requests for retain to avoid rate limits
export HINDSIGHT_API_RETAIN_LLM_MAX_CONCURRENT=3

# Fail faster with fewer retries
export HINDSIGHT_API_RETAIN_LLM_MAX_RETRIES=3

# Or increase backoff times to wait out rate limit windows
export HINDSIGHT_API_RETAIN_LLM_INITIAL_BACKOFF=2.0  # Start at 2s instead of 1s
export HINDSIGHT_API_RETAIN_LLM_MAX_BACKOFF=120.0    # Cap at 2min instead of 1min

Embeddings

Variable	Description	Default
HINDSIGHT_API_EMBEDDINGS_PROVIDER	Provider: local, tei, openai, cohere, or litellm	local
HINDSIGHT_API_EMBEDDINGS_LOCAL_MODEL	Model for local provider	BAAI/bge-small-en-v1.5
HINDSIGHT_API_EMBEDDINGS_TEI_URL	TEI server URL	-
HINDSIGHT_API_EMBEDDINGS_OPENAI_API_KEY	OpenAI API key (falls back to HINDSIGHT_API_LLM_API_KEY)	-
HINDSIGHT_API_EMBEDDINGS_OPENAI_MODEL	OpenAI embedding model	text-embedding-3-small
HINDSIGHT_API_EMBEDDINGS_OPENAI_BASE_URL	Custom base URL for OpenAI-compatible API (e.g., Azure OpenAI)	-
HINDSIGHT_API_COHERE_API_KEY	Cohere API key (shared for embeddings and reranker)	-
HINDSIGHT_API_EMBEDDINGS_COHERE_MODEL	Cohere embedding model	embed-english-v3.0
HINDSIGHT_API_EMBEDDINGS_COHERE_BASE_URL	Custom base URL for Cohere-compatible API (e.g., Azure-hosted)	-
HINDSIGHT_API_LITELLM_API_BASE	LiteLLM proxy base URL (shared for embeddings and reranker)	http://localhost:4000
HINDSIGHT_API_LITELLM_API_KEY	LiteLLM proxy API key (optional, depends on proxy config)	-
HINDSIGHT_API_EMBEDDINGS_LITELLM_MODEL	LiteLLM embedding model (use provider prefix, e.g., cohere/embed-english-v3.0)	text-embedding-3-small

# Local (default) - uses SentenceTransformers
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=local
export HINDSIGHT_API_EMBEDDINGS_LOCAL_MODEL=BAAI/bge-small-en-v1.5

# OpenAI - cloud-based embeddings
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=openai
export HINDSIGHT_API_EMBEDDINGS_OPENAI_API_KEY=sk-xxxxxxxxxxxx  # or reuses HINDSIGHT_API_LLM_API_KEY
export HINDSIGHT_API_EMBEDDINGS_OPENAI_MODEL=text-embedding-3-small  # 1536 dimensions

# Azure OpenAI - embeddings via Azure endpoint
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=openai
export HINDSIGHT_API_EMBEDDINGS_OPENAI_API_KEY=your-azure-api-key
export HINDSIGHT_API_EMBEDDINGS_OPENAI_MODEL=text-embedding-3-small
export HINDSIGHT_API_EMBEDDINGS_OPENAI_BASE_URL=https://your-resource.openai.azure.com/openai/deployments/your-deployment

# TEI - HuggingFace Text Embeddings Inference (recommended for production)
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=tei
export HINDSIGHT_API_EMBEDDINGS_TEI_URL=http://localhost:8080

# Cohere - cloud-based embeddings
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=cohere
export HINDSIGHT_API_COHERE_API_KEY=your-api-key
export HINDSIGHT_API_EMBEDDINGS_COHERE_MODEL=embed-english-v3.0  # 1024 dimensions

# Azure-hosted Cohere - embeddings via custom endpoint
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=cohere
export HINDSIGHT_API_COHERE_API_KEY=your-azure-api-key
export HINDSIGHT_API_EMBEDDINGS_COHERE_MODEL=embed-english-v3.0
export HINDSIGHT_API_EMBEDDINGS_COHERE_BASE_URL=https://your-azure-cohere-endpoint.com

# LiteLLM proxy - unified gateway for multiple providers
export HINDSIGHT_API_EMBEDDINGS_PROVIDER=litellm
export HINDSIGHT_API_LITELLM_API_BASE=http://localhost:4000
export HINDSIGHT_API_LITELLM_API_KEY=your-litellm-key  # optional
export HINDSIGHT_API_EMBEDDINGS_LITELLM_MODEL=text-embedding-3-small  # or cohere/embed-english-v3.0

Embedding Dimensions

Hindsight automatically detects the embedding dimension from the model at startup and adjusts the database schema accordingly. The default model (BAAI/bge-small-en-v1.5) produces 384-dimensional vectors, while OpenAI models produce 1536 or 3072 dimensions.

:::warning Dimension Changes Once memories are stored, you cannot change the embedding dimension without losing data. If you need to switch to a model with different dimensions:

1. Empty database: The schema is adjusted automatically on startup
2. Existing data: Either delete all memories first, or use a model with matching dimensions

Supported OpenAI embedding dimensions:

• text-embedding-3-small: 1536 dimensions
• text-embedding-3-large: 3072 dimensions
• text-embedding-ada-002: 1536 dimensions (legacy) :::

Reranker

Variable	Description	Default
HINDSIGHT_API_RERANKER_PROVIDER	Provider: local, tei, cohere, flashrank, litellm, or rrf	local
HINDSIGHT_API_RERANKER_LOCAL_MODEL	Model for local provider	cross-encoder/ms-marco-MiniLM-L-6-v2
HINDSIGHT_API_RERANKER_LOCAL_MAX_CONCURRENT	Max concurrent local reranking (prevents CPU thrashing under load)	4
HINDSIGHT_API_RERANKER_TEI_URL	TEI server URL	-
HINDSIGHT_API_RERANKER_TEI_BATCH_SIZE	Batch size for TEI reranking	128
HINDSIGHT_API_RERANKER_TEI_MAX_CONCURRENT	Max concurrent TEI reranking requests	8
HINDSIGHT_API_RERANKER_COHERE_MODEL	Cohere rerank model	rerank-english-v3.0
HINDSIGHT_API_RERANKER_COHERE_BASE_URL	Custom base URL for Cohere-compatible API (e.g., Azure-hosted)	-
HINDSIGHT_API_RERANKER_LITELLM_MODEL	LiteLLM rerank model (use provider prefix, e.g., cohere/rerank-english-v3.0)	cohere/rerank-english-v3.0
HINDSIGHT_API_RERANKER_FLASHRANK_MODEL	FlashRank model for fast CPU-based reranking	ms-marco-MiniLM-L-12-v2
HINDSIGHT_API_RERANKER_FLASHRANK_CACHE_DIR	Cache directory for FlashRank models	System default

# Local (default) - uses SentenceTransformers CrossEncoder
export HINDSIGHT_API_RERANKER_PROVIDER=local
export HINDSIGHT_API_RERANKER_LOCAL_MODEL=cross-encoder/ms-marco-MiniLM-L-6-v2

# TEI - for high-performance inference
export HINDSIGHT_API_RERANKER_PROVIDER=tei
export HINDSIGHT_API_RERANKER_TEI_URL=http://localhost:8081

# Cohere - cloud-based reranking
export HINDSIGHT_API_RERANKER_PROVIDER=cohere
export HINDSIGHT_API_COHERE_API_KEY=your-api-key  # shared with embeddings
export HINDSIGHT_API_RERANKER_COHERE_MODEL=rerank-english-v3.0

# Azure-hosted Cohere - reranking via custom endpoint
export HINDSIGHT_API_RERANKER_PROVIDER=cohere
export HINDSIGHT_API_COHERE_API_KEY=your-azure-api-key
export HINDSIGHT_API_RERANKER_COHERE_MODEL=rerank-english-v3.0
export HINDSIGHT_API_RERANKER_COHERE_BASE_URL=https://your-azure-cohere-endpoint.com

# LiteLLM proxy - unified gateway for multiple reranking providers
export HINDSIGHT_API_RERANKER_PROVIDER=litellm
export HINDSIGHT_API_LITELLM_API_BASE=http://localhost:4000
export HINDSIGHT_API_LITELLM_API_KEY=your-litellm-key  # optional
export HINDSIGHT_API_RERANKER_LITELLM_MODEL=cohere/rerank-english-v3.0  # or voyage/rerank-2, together_ai/...

LiteLLM supports multiple reranking providers via the /rerank endpoint:

• Cohere (cohere/rerank-english-v3.0, cohere/rerank-multilingual-v3.0)
• Together AI (together_ai/...)
• Voyage AI (voyage/rerank-2)
• Jina AI (jina_ai/...)
• AWS Bedrock (bedrock/...)

Authentication

By default, Hindsight runs without authentication. For production deployments, enable API key authentication using the built-in tenant extension:

# Enable the built-in API key authentication
export HINDSIGHT_API_TENANT_EXTENSION=hindsight_api.extensions.builtin.tenant:ApiKeyTenantExtension
export HINDSIGHT_API_TENANT_API_KEY=your-secret-api-key

When enabled, all requests must include the API key in the Authorization header:

curl -H "Authorization: Bearer your-secret-api-key" \
  http://localhost:8888/v1/default/banks

Requests without a valid API key receive a 401 Unauthorized response.

:::tip Custom Authentication For advanced authentication (JWT, OAuth, multi-tenant schemas), implement a custom TenantExtension. See the Extensions documentation for details. :::

Server

Variable	Description	Default
HINDSIGHT_API_HOST	Bind address	0.0.0.0
HINDSIGHT_API_PORT	Server port	8888
HINDSIGHT_API_WORKERS	Number of uvicorn worker processes	1
HINDSIGHT_API_LOG_LEVEL	Log level: debug, info, warning, error	info
HINDSIGHT_API_LOG_FORMAT	Log format: text or json (structured logging for cloud platforms)	text
HINDSIGHT_API_MCP_ENABLED	Enable MCP server at /mcp/{bank_id}/	true

Retrieval

Variable	Description	Default
HINDSIGHT_API_GRAPH_RETRIEVER	Graph retrieval algorithm: link_expansion, mpfp, or bfs	link_expansion
HINDSIGHT_API_RECALL_MAX_CONCURRENT	Max concurrent recall operations per worker (backpressure)	32
HINDSIGHT_API_RECALL_CONNECTION_BUDGET	Max concurrent DB connections per recall operation	4
HINDSIGHT_API_RERANKER_MAX_CANDIDATES	Max candidates to rerank per recall (RRF pre-filters the rest)	300
HINDSIGHT_API_MPFP_TOP_K_NEIGHBORS	Fan-out limit per node in MPFP graph traversal	20
HINDSIGHT_API_MENTAL_MODEL_REFRESH_CONCURRENCY	Max concurrent mental model refreshes	8

Graph Retrieval Algorithms

• link_expansion (default): Fast, simple graph expansion from semantic seeds via entity co-occurrence and causal links. Target latency under 100ms. Recommended for most use cases.
• mpfp: Multi-Path Fact Propagation - iterative graph traversal with activation spreading. More thorough but slower.
• bfs: Breadth-first search from seed facts. Simple but less effective for large graphs.

Retain

Controls the retain (memory ingestion) pipeline.

Variable	Description	Default
HINDSIGHT_API_RETAIN_MAX_COMPLETION_TOKENS	Max completion tokens for fact extraction LLM calls	64000
HINDSIGHT_API_RETAIN_CHUNK_SIZE	Max characters per chunk for fact extraction. Larger chunks extract fewer LLM calls but may lose context.	3000
HINDSIGHT_API_RETAIN_EXTRACTION_MODE	Fact extraction mode: concise, verbose, or custom	concise
HINDSIGHT_API_RETAIN_CUSTOM_INSTRUCTIONS	Custom extraction guidelines (only used when mode is custom)	-
HINDSIGHT_API_RETAIN_EXTRACT_CAUSAL_LINKS	Extract causal relationships between facts	true

Extraction Modes

The extraction mode controls how aggressively facts are extracted from content:

• concise (default): Selective extraction that focuses on significant, long-term valuable facts. Filters out greetings, filler, and trivial information. Produces fewer but higher-quality facts with better performance.

• verbose: Detailed extraction that captures every piece of information with maximum verbosity. Produces more facts with extensive detail but slower performance and higher token usage.

• custom: Inject your own extraction guidelines while keeping the structural parts of the prompt (output format, coreference resolution, temporal handling, etc.) intact. Useful for A/B testing different extraction strategies or domain-specific customization.

Example: Custom Extraction Mode

# Set mode to custom
export HINDSIGHT_API_RETAIN_EXTRACTION_MODE=custom

# Define custom guidelines (multi-line is fine)
export HINDSIGHT_API_RETAIN_CUSTOM_INSTRUCTIONS="ONLY extract facts that are:
✅ Technical decisions and their rationale
✅ Architecture patterns and design choices
✅ Performance metrics and benchmarks
✅ Code reviews and feedback

DO NOT extract:
❌ Generic greetings or pleasantries
❌ Process chatter (\"let me check\", \"one moment\")
❌ Repeated information already captured

CONSOLIDATE related technical discussions into ONE fact when possible.

Ask yourself: 'Would this technical context be useful in 6 months?' If no, skip it."

Observations (Experimental)

Observations are consolidated knowledge synthesized from facts.

Variable	Description	Default
HINDSIGHT_API_ENABLE_OBSERVATIONS	Enable observation consolidation	true
HINDSIGHT_API_CONSOLIDATION_BATCH_SIZE	Memories to load per batch (internal optimization)	50
HINDSIGHT_API_CONSOLIDATION_MAX_TOKENS	Max tokens for recall when finding related observations during consolidation	1024
HINDSIGHT_API_RETAIN_OBSERVATIONS_ASYNC	Run observation generation asynchronously (after retain completes)	false

Reflect

Variable	Description	Default
HINDSIGHT_API_REFLECT_MAX_ITERATIONS	Max tool call iterations before forcing a response	10

Local MCP Server

Configuration for the local MCP server (hindsight-local-mcp command).

Variable	Description	Default
HINDSIGHT_API_MCP_LOCAL_BANK_ID	Memory bank ID for local MCP	mcp
HINDSIGHT_API_MCP_INSTRUCTIONS	Additional instructions appended to retain/recall tool descriptions	-

# Example: instruct MCP to also store assistant actions
export HINDSIGHT_API_MCP_INSTRUCTIONS="Also store every action you take, including tool calls and decisions made."

Distributed Workers

Configuration for background task processing. By default, the API processes tasks internally. For high-throughput deployments, run dedicated workers. See Services - Worker Service for details.

Variable	Description	Default
HINDSIGHT_API_WORKER_ENABLED	Enable internal worker in API process	true
HINDSIGHT_API_WORKER_ID	Unique worker identifier	hostname
HINDSIGHT_API_WORKER_POLL_INTERVAL_MS	Database polling interval in milliseconds	500
HINDSIGHT_API_WORKER_BATCH_SIZE	Tasks to claim per poll cycle	10
HINDSIGHT_API_WORKER_MAX_RETRIES	Max retries before marking task failed	3
HINDSIGHT_API_WORKER_HTTP_PORT	HTTP port for worker metrics/health (worker CLI only)	8889

Performance Optimization

Variable	Description	Default
HINDSIGHT_API_SKIP_LLM_VERIFICATION	Skip LLM connection check on startup	false
HINDSIGHT_API_LAZY_RERANKER	Lazy-load reranker model (faster startup)	false

Programmatic Configuration

You can also configure the API programmatically using MemoryEngine.from_env():

from hindsight_api import MemoryEngine

memory = MemoryEngine.from_env()
await memory.initialize()

---

Control Plane

The Control Plane is the web UI for managing memory banks.

Variable	Description	Default
HINDSIGHT_CP_DATAPLANE_API_URL	URL of the API service	http://localhost:8888

# Point Control Plane to a remote API service
export HINDSIGHT_CP_DATAPLANE_API_URL=http://api.example.com:8888

---

Example .env File

# API Service
HINDSIGHT_API_DATABASE_URL=postgresql://hindsight:hindsight_dev@localhost:5432/hindsight
# HINDSIGHT_API_DATABASE_SCHEMA=public  # optional, defaults to 'public'
HINDSIGHT_API_LLM_PROVIDER=groq
HINDSIGHT_API_LLM_API_KEY=gsk_xxxxxxxxxxxx

# Authentication (optional, recommended for production)
# HINDSIGHT_API_TENANT_EXTENSION=hindsight_api.extensions.builtin.tenant:ApiKeyTenantExtension
# HINDSIGHT_API_TENANT_API_KEY=your-secret-api-key

# Control Plane
HINDSIGHT_CP_DATAPLANE_API_URL=http://localhost:8888

---

For configuration issues not covered here, please open an issue on GitHub.