> ## Documentation Index
> Fetch the complete documentation index at: https://docs.get-exo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Assert an edge

> Assert a developer-authored edge between two nodes the subject owns.

Provenance is stamped `origin=api` (via `created_by` +
`directionality_source`) and the edge `weight`/`confidence` are capped
at `ASSERTED_EDGE_AUTHORITY_CAP` (0.4) so a leaked key cannot inject a
dominating edge into the identity graph. NLI contradiction
screening is SKIPPED in v1 (documented). Both endpoints must be owned by the
effective subject; otherwise 404. Idempotent on the deterministic edge id.

## Authorization

This route requires the `graph:write` scope. A key carrying `memory:forget` or `write` also qualifies.

A missing or invalid credential returns 401 [`authentication_error`](/errors/authentication_error). A valid credential without the scope returns 403 [`permission_denied`](/errors/permission_denied), and the problem body names the exact scope required.

## Headers

These are request conventions the contract does not declare as parameters, so they do not appear in the schema tables below.

| Header            | Applies  | What it does                                                                                                                                           |
| ----------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `X-Exo-API-Key`   | Required | Your Exo API key, `exo_<env>_<token>`. `Authorization: Bearer exo_...` is accepted as an alternate.                                                    |
| `X-Exo-Subject`   | Optional | Acts for a provisioned subject instead of the key owner. An unprovisioned id returns 403 [`subject_not_provisioned`](/errors/subject_not_provisioned). |
| `Idempotency-Key` | Honoured | Makes a retry safe. The same key with the same body replays the original response instead of acting twice. See [Idempotency](/platform/idempotency).   |
| `X-Request-Id`    | Response | Returned on every response, including `204`s. Quote it in a support request.                                                                           |

## Success responses

| Status | Meaning             |
| ------ | ------------------- |
| `201`  | Successful Response |

## Errors

| Status | Code                                                   | When                                                           |
| ------ | ------------------------------------------------------ | -------------------------------------------------------------- |
| `400`  | [`invalid_request`](/errors/invalid_request)           | Malformed request, for example an invalid cursor.              |
| `401`  | [`authentication_error`](/errors/authentication_error) | Missing or invalid credentials.                                |
| `403`  | [`permission_denied`](/errors/permission_denied)       | Missing scope, or an unprovisioned subject selector.           |
| `404`  | [`not_found`](/errors/not_found)                       | The resource does not exist, or is not visible to this caller. |
| `409`  | [`conflict`](/errors/conflict)                         | A conflict with the current state of the resource.             |
| `422`  | [`validation_error`](/errors/validation_error)         | The request was understood but failed field validation.        |
| `429`  | [`rate_limit_exceeded`](/errors/rate_limit_exceeded)   | Rate limit exceeded. Retry after the Retry-After interval.     |
| `503`  | [`service_degraded`](/errors/service_degraded)         | A dependency is temporarily unavailable. Safe to retry.        |

Beyond the shared statuses, this route can answer with [`idempotency_in_flight`](/errors/idempotency_in_flight), [`idempotency_key_reuse`](/errors/idempotency_key_reuse). Every problem body names its own `code`, and the `type` URI always resolves to the matching page.

Every error is an RFC 9457 `application/problem+json` body carrying a stable `code`, a `requestId`, and a `suggestedAction` where Exo has one. See [Errors](/platform/errors).

## Notes

* **Asserted edges are capped.** `weight` and confidence are limited to 0.4, so organic evidence always outranks an assertion and a leaked key cannot inject a dominating edge.
* **Provenance is stamped `origin: "api"`**, which is what lets you tell your assertions apart from what Exo inferred.
* **Contradiction screening is skipped in v1.** Asserting an edge that conflicts with existing evidence is accepted rather than refused.
* **Idempotent on a deterministic edge id.** Asserting the same edge twice does not create two edges.


## OpenAPI

````yaml openapi.json POST /v1/graph/edges
openapi: 3.1.0
info:
  contact:
    name: Exo
    url: https://get-exo.com/
  description: >-
    The Exo public developer API: ingest content, retrieve identity-conditioned
    context, and read the knowledge graph. Authenticate every request with an
    Exo API key, either as the X-Exo-API-Key header or as Authorization: Bearer
    exo_... . Errors follow RFC 9457 problem+json with a stable snake_case code
    on every body.
  title: Exo API
  version: 1.0.0
servers:
  - url: https://api.get-exo.com
security:
  - ApiKeyHeader: []
  - BearerAuth: []
tags:
  - name: retrieve
    x-group: Retrieval
  - name: search
    x-group: Search
  - name: ingest
    x-group: Ingestion
  - name: jobs
    x-group: Jobs
  - name: subjects
    x-group: Subjects
  - name: recall
    x-group: Recall
  - name: graph
    x-group: Graph
  - name: insights
    x-group: Contradictions and proposals
  - name: condition
    x-group: Condition
  - name: brain
    x-group: Brain
  - name: sessions
    x-group: Coding sessions
  - name: connectors
    x-group: Connectors
  - name: events
    x-group: Events and webhooks
  - name: meta
    x-group: Identity
  - name: keys
    x-group: Keys and sandbox
  - name: usage
    x-group: Usage
  - name: settings
    x-group: Settings
  - name: exports
    x-group: Exports
  - name: team
    x-group: Team
  - name: admin
    x-group: Account and purge
paths:
  /v1/graph/edges:
    post:
      tags:
        - graph
      summary: Assert an edge
      description: >-
        Assert a developer-authored edge between two nodes the subject owns.


        Provenance is stamped ``origin=api`` (via ``created_by`` +

        ``directionality_source``) and the edge ``weight``/``confidence`` are
        capped

        at ``ASSERTED_EDGE_AUTHORITY_CAP`` (0.4) so a leaked key cannot inject a

        dominating edge into the identity graph (spec section 6). NLI
        contradiction

        screening is SKIPPED in v1 (documented). Both endpoints must be owned by
        the

        effective subject; otherwise 404. Idempotent on the deterministic edge
        id.


        Scope: ``graph:write`` (a ``write`` key also qualifies).
      operationId: assertEdge
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/EdgeAssertRequest'
        required: true
      responses:
        '201':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AssertedGraphEdge'
          description: Successful Response
        '400':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Malformed request, for example an invalid cursor.
        '401':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Missing or invalid credentials
        '403':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Missing scope or unprovisioned subject
        '404':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: No such node owned by the effective subject
        '409':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Conflict, for example a duplicate in-flight idempotent request.
        '422':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Validation Error
        '429':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: Rate limit exceeded
        '503':
          content:
            application/problem+json:
              schema:
                $ref: '#/components/schemas/Problem'
          description: A dependency is unavailable
components:
  schemas:
    EdgeAssertRequest:
      description: >-
        Body for POST /v1/graph/edges. Both endpoints must be owned by the

        effective subject. ``weight`` is capped at
        ``ASSERTED_EDGE_AUTHORITY_CAP``.
      properties:
        edgeType:
          default: relates_to
          maxLength: 200
          title: Edgetype
          type: string
        rationale:
          anyOf:
            - maxLength: 4000
              type: string
            - type: 'null'
          title: Rationale
        sourceNodeId:
          maxLength: 512
          title: Sourcenodeid
          type: string
        targetNodeId:
          maxLength: 512
          title: Targetnodeid
          type: string
        weight:
          anyOf:
            - type: number
            - type: 'null'
          title: Weight
      required:
        - sourceNodeId
        - targetNodeId
      title: EdgeAssertRequest
      type: object
    AssertedGraphEdge:
      description: >-
        An edge asserted through the API, as stored.


        Returned by POST /v1/graph/edges. ``origin`` is always ``api`` and
        ``weight``

        is the capped value actually written (see the asserted-edge authority
        cap),

        which may be lower than the weight requested.
      properties:
        edgeType:
          title: Edgetype
          type: string
        id:
          title: Id
          type: string
        origin:
          default: api
          title: Origin
          type: string
        rationale:
          anyOf:
            - type: string
            - type: 'null'
          title: Rationale
        sourceNodeId:
          title: Sourcenodeid
          type: string
        targetNodeId:
          title: Targetnodeid
          type: string
        weight:
          title: Weight
          type: number
      required:
        - id
        - sourceNodeId
        - targetNodeId
        - edgeType
        - weight
      title: AssertedGraphEdge
      type: object
    Problem:
      description: |-
        RFC 9457 problem+json envelope (spec D9), documented in OpenAPI.

        Invariant: ``code`` equals the tail of the ``type`` URI
        (``https://docs.get-exo.com/errors/<code>``).
      properties:
        code:
          title: Code
          type: string
        detail:
          title: Detail
          type: string
        documentationUrl:
          anyOf:
            - type: string
            - type: 'null'
          title: Documentationurl
        errors:
          anyOf:
            - items:
                $ref: '#/components/schemas/FieldViolation'
              type: array
            - type: 'null'
          title: Errors
        requestId:
          default: ''
          title: Requestid
          type: string
        status:
          title: Status
          type: integer
        suggestedAction:
          anyOf:
            - type: string
            - type: 'null'
          title: Suggestedaction
        title:
          title: Title
          type: string
        type:
          title: Type
          type: string
      required:
        - type
        - title
        - status
        - detail
        - code
      title: Problem
      type: object
    FieldViolation:
      description: A single field-level violation inside a Problem ``errors[]`` list.
      properties:
        code:
          title: Code
          type: string
        field:
          title: Field
          type: string
        message:
          title: Message
          type: string
        pointer:
          title: Pointer
          type: string
      required:
        - pointer
        - field
        - code
        - message
      title: FieldViolation
      type: object
  securitySchemes:
    ApiKeyHeader:
      description: An Exo API key (exo_...) sent as the X-Exo-API-Key header.
      in: header
      name: X-Exo-API-Key
      type: apiKey
    BearerAuth:
      description: The same Exo API key (exo_...) sent as an Authorization bearer token.
      scheme: bearer
      type: http

````