> ## Documentation Index
> Fetch the complete documentation index at: https://docs.melso.ai/llms.txt
> Use this file to discover all available pages before exploring further.
> ## Agent Instructions
> Melso product MCP: https://melso.ai/api/mcp (OAuth; one company per grant). REST: https://melso.ai. Documentation-search MCP: https://docs.melso.ai/mcp. The docs search server does not act on customer accounts.
>
> Use the live tool schema and respect company membership. Ask the person to authorize the exact fiscal document version in the signed-in app. A professional prepares and files included returns after authorization; AI does not file alone. A prepared file or approval receipt is not evidence of filing. Never claim completion from an accepted Task or Run. Keep credentials out of chat and logs. Agents features are internal or by private invitation.
# Upload file
> MCP OAuth token; acts in its granted workspace. Run credentials retain their Task scope.
Request: Multipart `file:binary` required; same size limit (under 100 MiB per request on melso.ai and mcp.melso.ai) and optional Task/message/Run association fields as POST /api/upload-file in [Tasks](/concepts/tasks-api). Upload each file separately.
Response: AttachmentResponse (see Tasks). Pass returned IDs as `attachment_ids:UUID[]` to `tasks_create` or `tasks_send`.
Status: 200; 400 invalid upload; 403 denied; 503 storage unavailable. Authentication and resource-access errors follow [Overview](/api-reference/errors).
## OpenAPI
````yaml /api-reference/openapi.json post /mcp/upload-file
openapi: 3.1.0
info:
title: Melso API
version: '2026-10-12'
description: >-
Customer integration contracts for Melso. Agents access is internal or by
private invitation. Fiscal approval remains in the authenticated app.
contact:
name: Melso
url: https://melso.ai/en
servers:
- url: https://melso.ai
description: Production API origin
security: []
tags:
- name: Areas
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Areas operations available within the caller's documented permissions.
- name: Artifacts
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Artifacts operations available within the caller's documented permissions.
- name: Authentication
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Authentication operations available within the caller's documented
permissions.
- name: Automations
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Automations operations available within the caller's documented
permissions.
- name: Companies
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Companies operations available within the caller's documented permissions.
- name: Execution funding
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Execution funding operations available within the caller's documented
permissions.
- name: Files
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Files operations available within the caller's documented permissions.
- name: GitHub
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
GitHub operations available within the caller's documented permissions.
- name: Interactions
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Interactions operations available within the caller's documented
permissions.
- name: Knowledge
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Knowledge operations available within the caller's documented permissions.
- name: MCP
description: MCP operations available within the caller's documented permissions.
- name: Messages
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Messages operations available within the caller's documented permissions.
- name: OAuth
description: OAuth operations available within the caller's documented permissions.
- name: Private network
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Private network operations available within the caller's documented
permissions.
- name: Runs
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Runs operations available within the caller's documented permissions.
- name: Skills
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Skills operations available within the caller's documented permissions.
- name: Tasks
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Tasks operations available within the caller's documented permissions.
- name: Vault
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Vault operations available within the caller's documented permissions.
- name: Webhooks
description: >-
Melso Agents is available only internally or by private invitation.
Agents-specific features require existing access. For the autónomo fiscal
service, see [Get started](/essentials/quickstart).
Webhooks operations available within the caller's documented permissions.
paths:
/mcp/upload-file:
post:
tags:
- MCP
summary: Upload file
description: >-
MCP OAuth token; acts in its granted workspace. Run credentials retain
their Task scope.
Request: Multipart `file:binary` required; same size limit (under 100
MiB per request on melso.ai and mcp.melso.ai) and optional
Task/message/Run association fields as POST /api/upload-file in
[Tasks](/concepts/tasks-api). Upload each file separately.
Response: AttachmentResponse (see Tasks). Pass returned IDs as
`attachment_ids:UUID[]` to `tasks_create` or `tasks_send`.
Status: 200; 400 invalid upload; 403 denied; 503 storage unavailable.
Authentication and resource-access errors follow
[Overview](/api-reference/errors).
operationId: uploadFile3
parameters: []
requestBody:
required: true
content:
multipart/form-data:
schema:
type: object
properties:
file:
type: string
format: binary
task_id:
type: string
message_id:
type: string
run_id:
type: string
required:
- file
responses:
'200':
description: >-
AttachmentResponse (see Tasks). Pass returned IDs as
`attachment_ids:UUID[]` to `tasks_create` or `tasks_send`.
content:
application/json:
schema:
$ref: '#/components/schemas/AttachmentResponse'
'400':
description: Invalid request.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'401':
description: Authentication required.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'403':
description: Credential, company or resource access denied.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'404':
description: Resource unavailable to this caller.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'429':
description: Rate limited; respect Retry-After when present.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'500':
description: Server error.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
'503':
description: Request failed; see the operation contract for the condition.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
security:
- mcpOAuth:
- mcp:tools
- runToken: []
components:
schemas:
AttachmentResponse:
type: object
properties:
id:
type: string
workspace_id:
type: string
task_id:
anyOf:
- type: string
- type: 'null'
message_id:
anyOf:
- type: string
- type: 'null'
run_id:
anyOf:
- type: string
- type: 'null'
uploader_type:
type: string
uploader_id:
type: string
filename:
type: string
url:
type: string
download_url:
type: string
attachment_download_url:
type: string
markdown_url:
type: string
content_type:
type: string
size_bytes:
type: integer
created_at:
type: string
required:
- id
- workspace_id
- task_id
- message_id
- run_id
- uploader_type
- uploader_id
- filename
- url
- download_url
- markdown_url
- content_type
- size_bytes
- created_at
Error:
type: object
properties:
error:
type: string
code:
type: string
required:
- error
additionalProperties: true
securitySchemes:
mcpOAuth:
type: oauth2
flows:
authorizationCode:
authorizationUrl: https://app.melso.ai/oauth/authorize
tokenUrl: https://melso.ai/oauth/token
scopes:
mcp:tools: Call the tools available in the company selected at consent.
runToken:
type: http
scheme: bearer
description: Active Run token; execution-scoped permissions apply.
````
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