> ## Documentation Index > Fetch the complete documentation index at: https://ara-90a60a07.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Send a message on the caller's Reason Network > Reason Network's `send_message`. It goes out from one of the caller's own computers that is online with Reason running, as `/` (the agent named after the calling app), and returns once that computer reports the engine's delivery state per recipient; replies come back to `from` and land in `check_inbox`. Answers 409 when nothing went out at all: `agent_network_no_computer` (none of the user's computers is running Reason), `agent_network_not_taken` (the computer didn't take it in time; sending again is safe) or `agent_network_send_failed` (the engine refused it, as it refuses an agent's message to a group). 202 means the computer took it and hasn't reported yet. With `as`, the call is that chat's own session on the connection, `/`, with its own address and inbox; a blank one is none. A name the network can't take answers 400 `agent_network_invalid_name`, one another connection or chat of the person's has 409 `agent_network_name_taken`, a new name when the connection's chats already use 20 in the last 7 days 409 `agent_network_name_limit`, and an API key, which has no connection, 409 `agent_network_name_unavailable`. Scope: `run` ## OpenAPI ````yaml /openapi.json post /v3/organizations/{orgId}/agent-network/send openapi: 3.1.0 info: title: Reason API version: 3.0.0 description: >- The Reason HTTP API. Drive cloud software-engineering agents: open sessions against your repositories, stream their work, and manage the secrets, skills, and automations they run with. Authenticate with a Reason API key sent as a bearer token. New keys use `reason_`; legacy `ara_` keys remain accepted. Every resource is scoped to an organization; resolve your `org_id` once with `GET /v3/self`. servers: - url: https://api.reasonmachines.com security: - reasonApiKey: [] tags: - name: Account description: Verify a key and resolve the organization it belongs to. - name: Reasons description: >- Start here. A Reason is the long-running agent a person keeps: their main Reason and named ones, each with its own instructions, default model and repositories, conversation, Loops and Sessions. Give a Reason work by messaging it (sendReasonMessage) and read its replies with listReasonMessages. - name: Loops description: >- Standing work a Reason does, woken by a schedule or an event: a webhook, a GitHub event or a Slack message. Each wake opens or continues a Session of the Reason; webhook events that share a correlation key continue one Session. - name: Memory description: >- What Reasons remember across Sessions. Each Session starts by reading MEMORY.md (a short index) and the list of topic notes, and reads a note when its topic comes up. `personal` memory belongs to one person (the API key's owner) and only their Sessions read it; `team` memory belongs to the Workspace and every member's Sessions read it. memory:read lists, reads and searches; memory:write writes and deletes, in team memory only for a Workspace owner or admin. - name: Sessions description: >- A Session is one run of work inside a Reason: every Reason message and Loop wake runs in one, and createSession starts one directly for a single unattended task with a pass/fail outcome. Its transcript, events, result and pull request are read here. - name: Skills description: >- Reusable instruction bundles Reason selects semantically from their descriptions for matching agent tasks. - name: Secrets description: >- Encrypted credentials injected into the agent's sandbox. Write-only: values can be set but never read back. - name: Attachments description: >- Files uploaded to the organization and shared with sessions, downloaded via short-lived signed URLs. - name: Repositories description: Connected repositories, their indexing state, and generated wikis. - name: Git Connections description: Linked source-control accounts and the repositories they expose. - name: Machines description: >- Named Workspace queues served by headless workers. Sessions target a Machine by name and wait for a free worker; more workers serve more Sessions concurrently. - name: Devices description: >- Owned Mac and headless Device identity, bounded enrollment and root grants. - name: Cloud Access description: >- Keyless cloud sign-in for sessions: Reason's OIDC issuer facts and the AWS, Google Cloud and Azure connections a workspace trusts, including which run triggers each one signs in. - name: MCP Servers description: >- Org-level Model Context Protocol servers exposed to the agent. Secret values are write-only. - name: Change Request Reviews description: >- Automated senior-engineer reviews posted on pull requests and merge requests. - name: Consumption description: 'Billing-aligned usage: daily consumption and billing cycles.' - name: Metrics description: Aggregate analytics over sessions, change requests, and usage. - name: Audit Logs description: An append-only record of changes made within the organization. - name: Organizations description: The top-level tenant. Create, read, update, and delete organizations. - name: Members description: People in an organization and their pending invites. - name: Roles description: Role assignments that govern what each member can do. - name: Settings description: 'Organization configuration: namespaced settings and the run tag policy.' - name: Provider credentials description: >- Configure Bring-Your-Own-Key (BYOK) API keys and subscription credentials for model providers. Secret values are write-only. - name: Feedback description: Report problems with the API or these docs to the Reason team. - name: Projects description: >- Deprecated: a project is a Reason with the same id. Use the Reasons operations; these remain for existing clients. - name: Automations description: >- The older form of Loops. Prefer the Loops under a Reason (listReasonLoops, createReasonLoop), which take every wake: schedule, webhook, GitHub, Slack. Use these for what Loops do not carry yet: a run's MCP and app tools, and automations not filed under a Reason. paths: /v3/organizations/{orgId}/agent-network/send: parameters: - $ref: '#/components/parameters/orgId' post: tags: - Agent network summary: Send a message on the caller's Reason Network description: >- Reason Network's `send_message`. It goes out from one of the caller's own computers that is online with Reason running, as `/` (the agent named after the calling app), and returns once that computer reports the engine's delivery state per recipient; replies come back to `from` and land in `check_inbox`. Answers 409 when nothing went out at all: `agent_network_no_computer` (none of the user's computers is running Reason), `agent_network_not_taken` (the computer didn't take it in time; sending again is safe) or `agent_network_send_failed` (the engine refused it, as it refuses an agent's message to a group). 202 means the computer took it and hasn't reported yet. With `as`, the call is that chat's own session on the connection, `/`, with its own address and inbox; a blank one is none. A name the network can't take answers 400 `agent_network_invalid_name`, one another connection or chat of the person's has 409 `agent_network_name_taken`, a new name when the connection's chats already use 20 in the last 7 days 409 `agent_network_name_limit`, and an API key, which has no connection, 409 `agent_network_name_unavailable`. Scope: `run` operationId: sendNetworkMessage requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AgentNetworkSendRequest' responses: '200': description: What the network did with it, per recipient. content: application/json: schema: $ref: '#/components/schemas/AgentNetworkSendResponse' '202': description: The user's computer took it and hasn't reported yet. content: application/json: schema: $ref: '#/components/schemas/AgentNetworkSendResponse' '400': description: >- `as` isn't a name the network takes (`agent_network_invalid_name`); nothing went out. '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '409': description: >- Nothing went out (`agent_network_no_computer`, `agent_network_not_taken`, `agent_network_send_failed`, or for `as`, `agent_network_name_taken`, `agent_network_name_limit` and `agent_network_name_unavailable`). '429': $ref: '#/components/responses/RateLimited' security: - reasonApiKey: - run components: parameters: orgId: name: orgId in: path required: true description: Organization id or slug. Resolve it with `GET /v3/self`. schema: type: string schemas: AgentNetworkSendRequest: type: object properties: to: type: string minLength: 1 maxLength: 300 description: '"person/session" (or just "session").' message: type: string minLength: 1 maxLength: 30000 description: The message, with the point in the first line. reply_to: description: Id of the message you are replying to. type: - string - 'null' minLength: 1 maxLength: 100 notify: description: >- Also pop it up on that person's screen, for when they must act themselves (an approval, a decision). `to` may then be your own user's name, to reach them. type: - boolean - 'null' as: description: >- This chat's own name, such as editor, when the user talks to Reason Network from several chats of this app: the call is then that chat's own session, person/editor, with its own inbox, and a name another connection or chat of the user's has is refused. 1 to 32 lowercase letters, digits and dashes. Left out or blank, the connection's own session. type: - string - 'null' maxLength: 300 required: - to - message AgentNetworkSendResponse: type: object properties: from: description: >- The address it went out from, which replies reach and land in `check_inbox`. type: - string - 'null' ids: type: array items: type: string description: The network's id for the message; a reply names it as `reply_to`. recipients: type: array items: type: object properties: address: type: string state: description: >- The engine's delivery state: pushed, delivered, queued (kept until the session or its computer takes it), refused, held, notified, not notified or retry. Null from a computer whose Reason CLI doesn't report it. type: - string - 'null' note: type: string description: The engine's explanation of the state for this recipient. required: - address - state - note unread: description: >- Messages to the caller's agent it hasn't read, and who sent them, as `check_inbox` returns them; null when there are none. type: - object - 'null' properties: count: type: integer from: type: array items: type: string required: - count - from note: type: - string - 'null' required: - from - ids - recipients - unread - note Error: type: object properties: error: oneOf: - type: string - type: object required: - type - message properties: type: type: string message: type: string request_id: type: - string - 'null' message: type: string required_scope: type: string description: >- The capability required when the request was denied for a missing scope. responses: Unauthorized: description: Missing, invalid, or expired key. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: missing_bearer message: Authorization required Forbidden: description: The key lacks the required scope or role. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: missing_scope required_scope: sessions:read RateLimited: description: >- Too many requests. Retry after the number of seconds in the `Retry-After` response header. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer minimum: 1 required: true content: application/json: schema: $ref: '#/components/schemas/Error' example: error: type: rate_limited message: This API key exceeded its request-rate limit securitySchemes: reasonApiKey: type: http scheme: bearer bearerFormat: 'reason_ (legacy: ara_)' description: >- Your Reason API key from Settings › API keys. New keys use `reason_`; legacy `ara_` keys remain accepted. Keys are capability-scoped: run, mcp:read, mcp:write, secrets:read, secrets:write, sessions:read, sessions:debug, knowledge:read, memory:read, memory:write, skills:read, skills:write, repos:read, repos:write, reviews:read, reviews:write, deployment:read, analytics:read, org:read, org:write, attachments:read, attachments:write, guardrails:read, guardrails:write, network:read, network:write, automations:read, automations:write, agent_auth:read. network:read and network:write are opt-in, excluded from default keys. network:read reads the saved workspace network policy; network:write replaces custom allowed hosts and requires a current organization owner/admin. Legacy project PATCH requests containing network_allowed_hosts also require network:write plus their existing run scope and project management permission; saved project hosts do not affect current session egress. Only owners/admins can mint or manage keys with network:write; keys cannot grant themselves more authority. See /docs/network-policies for replacement semantics and runtime applicability. mcp:write manages MCP server configuration only; it does not authorize remote MCP-tool execution. sessions:read reads sessions, including the assistant, reasoning and tool activity in their events. sessions:debug is privileged: only for organization owners/admins, it expands session events to the full diagnostic projection (diagnostic event kinds, status text and raw event metadata). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.