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What it does: Lets agents inspect or manipulate their own and others’ conversations, spawn sub-agents for specialized tasks, route messages between sessions, and reach into long-term memory. Who it’s for: Anyone building multi-agent setups, delegating work to specialists, or asking the agent to recall something it learned earlier. For multi-agent execution graphs (DAGs), see the dedicated Pipelines page — this page covers the simpler one-shot delegation primitives.

Session tools

The ctx_* tools are in-session recovery over the DAG (LCD) context engine’s lossless store — they are distinct from the cross-session recall tools (memory_search, session_search). See Context expansion tools below. For DAG-style multi-agent workflows (debate, vote, refine, map-reduce, etc.), see Pipelines — the pipeline tool is the canonical entry point.

Session tools

The four session tools (session_search, session_status, sessions_history, sessions_list) let agents inspect conversations and discover active sessions.
Shows the current session’s status including the agent ID, model, token usage, and duration.Parameters:Returns the current session’s metadata.
Lists all active sessions for the current agent, with optional filters by session kind and recency.Parameters:Returns a list of sessions with their session keys, agent assignments, channels, and last activity timestamps.
Retrieves the conversation history for a specific session by session key.Parameters:
Search across session messages using FTS keywords or boolean expressions.Parameters:

Cross-Agent Coordination

Sends a message into another session. This is the primary way agents communicate with each other. The three modes control how the sending agent waits for a response.Parameters:Modes explained:Example — Delegate a task and wait:
Example — Send a notification:
Creates a new sub-agent session with structured context. The spawned agent runs in an isolated workspace with its own conversation history and receives a context packet containing the task, artifact references, domain knowledge, and an optional objective that survives compaction.Parameters:When async is false (the default), the parent agent blocks until the sub-agent completes and returns its result. When async is true, the sub-agent runs in the background and the parent continues working. Use subagents to check on background sub-agents.Sub-agent results are automatically condensed (if over the token threshold) and formatted with metadata tags before being returned to the parent. See Subagent Context Lifecycle for the full pipeline.Example — Spawn a coding agent (sync):
Example — Spawn an async researcher:
Example — Spawn with artifacts and objective:
Manages sub-agents that were spawned with sessions_spawn. You can list running sub-agents, terminate them, or steer them with a new task.Parameters:Actions:Example — Check on sub-agents:
Example — Steer a running sub-agent:
For DAG-style multi-agent workflows — parallel research, debate, vote, sequential refinement, map-reduce, and human approval gates — use the dedicated pipeline tool. It has its own page with the full schema, the 7 built-in node type drivers, and worked examples.See Pipelines.

Memory tools — Long-term Memory

Agents have access to long-term memory that persists across conversations. Four dedicated tools cover the full memory lifecycle: memory_search for hybrid text and vector search, memory_get for reading entries by path, memory_store for persisting new information, and memory_manage for admin CRUD operations. Memory uses hybrid text and vector search, so agents can find relevant information even when the wording differs from the original.
Searches the agent’s long-term memory using hybrid text and vector similarity. Returns matching memory entries ranked by relevance.Parameters:Returns matching entries with their paths, content previews, and relevance scores.Example:
Reads memory file sections by path, with an optional line range.Parameters:
Explicitly stores information in the agent’s long-term memory. While Comis automatically stores important information from conversations, this lets agents deliberately save specific facts, preferences, or notes.Parameters:Example:
Comis has built-in secret detection. Attempting to store API keys, passwords, tokens, or other secrets will be blocked automatically. This protects against accidental credential leakage into the memory system.
Admin-only memory CRUD operations. Requires admin trust level. The delete and flush sub-actions require user approval. pin/unpin mark a single entry as always-injected in recall.Parameters:

Context expansion tools

These three tools recover detail from the current conversation when the agent runs in DAG mode (contextEngine.version: "dag"). As a long, tool-heavy session grows past its token budget, the DAG (LCD) context engine compresses old turns into a zoomable summary hierarchy. The ctx_* tools let the agent zoom back in: search the compressed history, inspect a summary’s coverage, and rehydrate a compressed region back to its underlying messages.
In-session, not cross-session. The ctx_* tools operate only on the current conversation’s lossless store and share no code with the long-term recall tools. Use memory_search / session_search to recall information from other sessions; use ctx_* to recover detail the summarizer compressed away within this session. The ctx_* tools are DAG-mode-only — active by default (DAG is the default engine) and inactive only in the opt-in pipeline mode — never-export (never reachable via the Comis MCP server), and read-only — they never reach another session or tenant.
Full-text search over the current conversation’s lossless store (compressed messages and summaries). Uses SQLite FTS5 when available and falls back to a LIKE scan otherwise — it never hard-fails. Returns matching snippets, which are treated as untrusted recovered content.Parameters:
Inspects a single summary in the DAG: its depth, the time range and number of messages it covers, its token count, and its immediate children. Returns metadata only (no recovered content), so it is a cheap way to decide which region is worth expanding.Parameters:
Rehydrates a compressed region back to the underlying messages it covers. A region that partially drifted out of the store is recovered best-effort (the unrecoverable count is reported — expansion is never fatal). Large output is not inlined into the context: it is written to the session’s tool-results/ directory and returned as a file handle, which you can then open with the file tools (read). Recovered content is treated as untrusted.Parameters:

Sub-Agent Patterns

Sub-agents are one of the most powerful features in Comis. Here are common patterns for using them effectively:

Delegation

Spawn a specialist agent for a specific task. For example, a general-purpose assistant can spawn a coding agent to fix a bug, wait for the result, and report back to the user.

Parallel Work

Spawn multiple sub-agents to work on different parts of a problem simultaneously. Each sub-agent runs independently, and the parent collects results when they finish.

When to use sessions_spawn vs. pipeline

For all DAG patterns, see the dedicated Pipelines page.

Agent Sessions

How sessions work under the hood

Pipelines

Multi-agent DAG execution — the deep dive on the pipeline tool

Messaging

Send messages across channels

Agent Tools Overview

Master reference table of all tools